home *** CD-ROM | disk | FTP | other *** search
- Path: senator-bedfellow.mit.edu!dreaderd!not-for-mail
- Message-ID: <food/sourdough/faq_1084444382@rtfm.mit.edu>
- Supersedes: <food/sourdough/faq_1082881260@rtfm.mit.edu>
- Expires: 14 Jun 2004 10:33:02 GMT
- X-Last-Updated: 2003/12/22
- From: Darrell Greenwood <darrell.faq@telus.invalid>
- Newsgroups: rec.food.sourdough,rec.answers,news.answers
- Subject: rec.food.sourdough FAQ Questions and Answers
- Approved: news-answers-request@MIT.EDU
- Followup-To: rec.food.sourdough
- Organization: http://www.nyx.net/~dgreenw/
- Distribution: world
- Reply-To: darrell.faq@telus.invalid (replace .invalid with .net)
- X-Antispam: Replace .invalid with .net, i.e., darrell.faq at telus.net
- Summary: This posting is a collection of interesting and knowledgeable
- answers to frequently asked questions on newsgroup
- rec.food.sourdough.
- Keywords: FAQ sourdough bread
- Originator: faqserv@penguin-lust.MIT.EDU
- Date: 13 May 2004 10:34:17 GMT
- Lines: 3435
- NNTP-Posting-Host: penguin-lust.mit.edu
- X-Trace: 1084444457 senator-bedfellow.mit.edu 567 18.181.0.29
- Xref: senator-bedfellow.mit.edu rec.food.sourdough:33705 rec.answers:86990 news.answers:271217
-
- Archive-name: food/sourdough/faq
- Posting-Frequency: 18 days
- Last-modified: 2003/02/09
- URL: http://www.nyx.net/~dgreenw/sourdoughfaqs.html
-
- Subject: 1. Introduction and Where are the FAQs?
-
- This FAQ is a collection of excerpts from past postings to
- rec.food.sourdough. They answer frequently asked questions.
-
- The objective of this FAQ is not to duplicate information that is
- easily available in the several excellent FAQs; Starter Doctor FAQ,
- basicbread FAQ, and sourdough Recipes FAQ and other archived
- information already in existence at the unc archive site pointed to
- and hot linked by URL;
-
- http://www.nyx.net/~dgreenw/sourdoughfaqs.html
-
- This URL also has additional information on starter sources and a
- growing number of links to resources other than the archive site.
-
- If you are using an ftp client the ftp archive site only is located at;
- 'sunSITE.unc.edu' path pub/academic/agriculture/rural-skills/food/sourdough/.
-
- FTP appears quite limited in number of connections permitted so I
- recommend using the http server at unc pointed to by
-
- http://www.nyx.net/~dgreenw/sourdoughfaqs.html if you can.
-
- A hypertext copy of the latest version of this FAQ is at URL;
-
- http://www.nyx.net/~dgreenw/sourdoughqa.html
-
- In addition to being posted in rec.food.sourdough, rec.answers, and
- news.answers monthly this faq, along with the other 3 regularly
- posted FAQs, is also archived at rtfm.mit.edu (18.181.0.24) in the
- directory
-
- /pub/usenet/news.answers/food/sourdough/
-
- as 'faq', 'starters', 'basicbread' and 'recipes'. This is useful if
- you do not have web access: the rtfm.mit.edu archival site permits
- both ftp and email retrieval of these files.
-
- To obtain these faqs, first try ftp to rtfm.mit.edu and look under
- that directory.
-
- If ftp does not work from your site, then try the mail server: send
- email to mail-server@rtfm.mit.edu with one or more of the following
- lines in the body of the message:
-
- send usenet/news.answers/food/sourdough/faq
-
- send usenet/news.answers/food/sourdough/starters
-
- send usenet/news.answers/food/sourdough/basicbread
-
- send usenet/news.answers/food/sourdough/recipes
-
-
- Contributions to this FAQ gratefully received.
-
- Authors are noted in the last section (99). The authors' first names
- are at the end of each of their contributions.
-
- ------------------------------
-
- Subject: 2. Table of Contents
-
- 1. Introduction and Where are the FAQs?
-
- 2. Table of Contents
-
- 3. What is the protein or gluten content of various flours?
-
- 4. What are some books on bread?
-
- 5. What is gluten and how does kneading develop it?
-
- 6. How do wild and commercial yeast differ?
-
- 7. Can I make bread without salt?
-
- 8. How do I stop my sourdough bread from flattening?
-
- 9. Can I use chlorinated water with my starter?
-
- 10. Does temperature of the starter have an effect on flavour?
-
- 11. What is diastatic malt?
-
- 12. What is meant by % hydration of a dough?
-
- 13. What is a sponge?
-
- 14. What is the difference between 'Classical' and 'Modern' sourdough?
-
- 15. How do I make soft buns?
-
- 16. How should I feed my starter for best results?
-
- 17. Are all starters the same?
-
- 18. What about Nancy Silverton's latest book?
-
- 19. How do I get that great crust?
-
- 20. How much starter do I need?
-
- 21. Sourdough Science 101 or How are the sourness and leavening of
- starters related?
-
- 22. What is the Microbiology of San Francisco Sourdough?
-
- 23. What about Ed Wood's latest edition of his book?
-
- 24. How can I start a starter from scratch?
-
- 25. How do I get holey, sour, moist and long keeping bread?
-
- 26. Is slashing of loaves aesthetic or functional?
-
- 27. How do lactic bacteria affect sourdough bread?
-
- 28. What is hooch? Refrigerator hooch? What do I do with it?
-
- 29. How can I determine the proportion of flour and water to use in
- my starter and dough?
-
- 30. How can I ship my starter to someone else?
-
- 31. How do I get that lofty loaf?
-
- 32. What is San Francisco Sourdough?
-
- 33. What temperature should my starter be for best results?
-
- 34. Can I freeze or dry my starter?
-
- 35. What happens if I start my starter with commercial yeast?
-
- 36. What do all these baker's terms like poolish, biga, chef, mean?
-
- 37. What is the relationship between temperature and sourdough activity?
-
- 38. Is there a glossary of rec.food.sourdough terms?
-
- 39. What factors affect microbial growth in sourdough
-
- 40. Should I use an established starter or make my own starter?
-
- 41. Can I use metal utensils with sourdough?
-
- 42. What is a good source for technical information on sourdough starters?
-
- 43. How do I convert yeast bread recipes to SD recipes?
-
- 44. What is meant by a "fully activated" starter?
-
- 45. What about Dan Wing's new book "The Bread Builders"?
-
- 46. What's all this about natural leaven and L. sanfranciscensis?
-
- 47.How does one measure the ph of sourdough, and what is the effect
- of different ph's?
-
- 48.Should I use more than one rise for my bread?
-
- 49. What is Salt Rising Bread?
-
- 99. Authors
-
- ------------------------------
-
- Subject: 3. What is the protein or gluten content of various flours?
-
- Cake flour is typically 7-9% protein; pastry, or cookie, ~9-10%; all
- purpose, 10-12%, bread, 12.5-13.5%, clear and high gluten, 14-15%;
- gluten "flour" (actually refined gluten), 45%. The protein consists
- of ~80% gluten, and the gluten of cake flour is weakest, and bread
- and high gluten flour the strongest, and the intermediate ones
- increasingly stronger. Gluten is more of less made up of equal parts
- of gliadin and glutenin.
-
- Gluten strength definition and measurement are not entirely well
- understood, even by cereal chemists. Generally, you want the most
- protein and strongest gluten for bagels and breads that also use
- other poor or non-gluten flours such as rye or oat; moderately strong
- for all wheat bread; weaker for pastries and cookies; still weaker
- for cakes such as pound cakes; yet still weaker for "high-ratio,"
- rich cakes; and weakest for angel food cakes. One of the quality
- tests for soft wheat flour is the "cookie spread test, which is one
- measure of this. There are also farinographs, elastographs, and
- whatnot to further attempt to measure this elusive property.
- Fortunately, with most flours, increasing protein content goes along
- with increasing gluten strength.
-
- -Jeff
-
- See also:
-
- Flour -- A Treatise: http://www.theartisan.net/Flours_One.htm
- Flour Test -- Flours of America: http://www.theartisan.net/flour_test.htm
-
- ------------------------------
-
- Subject: 4. What are some books on bread?
-
- I happen to be passionate about bread and own approximately 25 books
- on bread and have closely read numerous others. I will try and give
- you a tour of some of the books on bread, one
- introductory/intermediate, two current books focussing on "artisan"
- type breads and a few in the specialized to advanced category to give
- you a flavor of some of the books out there.
-
- The Laurel's Kitchen Bread book - A guide to Whole-Grain bread making
- by Laurel Robertson, Carol Flinders and Bronwen Godfrey is perhaps
- one of the best introductions to bread making.
-
- The books is aimed at people who want to bake with whole-grains but
- there is no reason you cannot use the principles with whatever form
- of flour you choose. She begins with a loaf for learning, thoroughly
- explains the principles of what you are trying to achieve (for
- example most books say something vague like "knead till elastic" she
- give you an objective end point - when dough is sufficiently kneaded
- you should be able to stretch the dough paper thin (insufficiently
- kneaded dough will tear or break long before you can stretch it this
- thin). She covers a wide variety of breads and methods, explains the
- effects of various ingredients and additives and has some unique
- material - for example she extols a Flemish "Desem" starter. She has
- tables to help you find recipes that fit into your schedule and adapt
- recipes to any baking schedule you choose. Everything she says is
- accurate (no small feat if you consider some of the stuff below).
- From the point of view of sourdough she is not a purist & in the
- context of a general book on bread I have no major quibble with that.
- The only flaw if you can call it one is there are no glossy pictures
- to inspire you. This is an issue because unfortunately many modern
- books have awfully good pictures that illustrate some important
- points (e.g. what does an "open" crumb vs fine crumb look like etc).
- It is sparsely referenced but has a few very authoritative references
- (Pyler "Baking Science and Technology" for example). A must buy for
- anyone learning to bake.
-
- The next three books focus on artisan type or regional breads:
-
- Joe Ortiz in the Village Baker says that in a trip to France he got a
- recipe for "pain ordinaire" and thought finally he had the long
- sought "secret recipe" only to discover that it was identical to the
- one he was already using! To him the lesson was the process was the
- important part not merely the ingredients and a good loaf was the
- result of successful mastery and manipulation of every step from
- choice of ingredients to mixing to baking. I think this is a good
- criterion to use to judge the current crop of bread books ( as well
- as older ones) - does the book give you sufficient information to
- understand the process so you can manipulate it to suit your own
- needs and tastes. I think the Ortiz book is very successful in this
- regard. It is really a condensation of several French masterpieces
- (cited in his bibliography) and is thus is a valuable resource for
- someone who is interested in Raymond Calvel or Lionel Poilane
- opinions on bread but cannot read the French originals. He explains
- the 3 basic kinds of dough (sponge, straight and sourdough). The
- importance of a number of variables and their effects like water
- (how wet the dough is) yeast, mixing conditions, temperature, wheat
- and how they end up altering the product. There is an incredible
- amount of information. Some of the info is laid out directly.
- Other parts will need lots of work on your part - he tells you a
- certain manipulation will affect say crumb but doesn't tell you why
- or in what direction - it does serve as a basis for experimentation
- however. I suspect he is not always clear about explaining the whys
- because he is an empirical baker. Having read some of the more
- Technical books by Pyler, Pomeranz, Stear etc I have come to
- understand the reasons why particular manipulations work. In short
- this book glorifies the method and is invaluable if this is what you
- want.
-
- No baker will agree with all his opinions on what a desirable
- approach to bread is, for example he recommends building sourdough
- starters relatively firm which is unlikely to pack the maximum flavor
- one can out of a sourdough (there are several good reasons to have a
- firm starter if one is only interested in good leavening). The other
- negative to me is that approximately a third of the book has recipes
- scaled up for the professional. This is an interesting curiosity but
- a waste to most home bakers. It has a good bibliography with
- classic primary sources. One could learn a lot from this over a long
- time - every rereading should uncover something new which could serve
- as the basis for experimentation. Not all of his opinions are
- correct, and there are technical missteps but since I am saving my
- venom for Daniel Leader I will pass on to him.
-
- Bread Alone - Daniel Leader and Judith Blahnik. I am lukewarm about
- this book. It is a very slick presentation that will seduce you with
- the romance of bread baking. It strings together a number of
- anecdotes in a racy style that is good entertainment. You will come
- out longing for a brick oven that he very skillfully mystifies and
- glorifies. It has pictures of very attractive loaves that are
- highly motivating. It extols the virtues of organic flour (a passion
- I share). Many of the recipes are on the trendy end - Country style
- loaf with figs and cognac and hazelnuts. The same with cilantro and
- cornmeal and coarse pepper etc. By the way he adds an additive like
- cilantro and cornmeal and considers this a new recipe in my book
- these should be considered variations. The book is very heavily
- padded with these variations and in actuality is very lean. I am not
- particularly impressed because only my imagination limits what
- concoctions I can come up with i.e. the hip recipes should not
- motivate you to buy this book. In fact it is the hipness that irks
- me. For example, he uses french terms for commonly used baking
- terms. Thus a sponge is a poolish, a sourdough is levain and so on.
- In no place does he explain the parallels and studiously avoids the
- common english terms. This is a slick way of packaging old wine in
- new bottles.
-
- He is factually wrong in a number of places. For example, he says
- that sourdough fanatics falsely treasure starters and he will
- demystify the process. He gives directions on starting your own
- starter and suggest adding yeast " as a magnet to attract the wild
- yeasts" -pure bull! Similarly he has a recipe for San Francisco
- Sourdough but uses the homemade starter. San Francisco Sourdough is
- not a process but requires the presence of a true starter with the
- characteristic organisms of San Francisco Sourdough - Candida milleri
- and Lactobacillus sanfrancisco. It is as likely that the ""Hearty
- Burgundy" of Ernest and Julio Gallo resembles the wines of Burgundy
- France as a homemade starter will have these particular organisms.
- (To be fair to Daniel Leader almost all books on bread commit this
- mistake in the obligatory "San Francisco Sourdough" recipe).
-
- On page 42 he says flour is "bromated" with potassium! (For you non
- scientists potassium bromate is used - with the bromate doing the
- brominating not potassium! Then on page 50 he has the strangest
- definition of first rise and second rise I have ever seen - he claims
- the yeast feed on free sugar in the first rise and the yeast release
- sugar from starch in the second rise. In truth there is very little
- free sugar in flour and once depleted the yeast are dependant on
- release of sugar from starch to continue to do their thing. When
- exactly this happens depends on the dough formulation, fermentation
- time and temperature etc etc. In fact in his lean long fermented
- poolish the yeast are very definitely living of starch & no rises
- have occurred at all! It is simply stupid to use his definitions. I
- heap so much venom because he is a graduate of the Culinary Institute
- of America, professional baker etc. and should have a better command
- of the facts. I would not nitpick if I found stuff like this in Marge
- Schlee's "Baking with Schmecks appeal !"
-
- Another aspect of the book that I dislike is that he repeats the most
- basic information for each step for every single recipe (many of
- which are variations in the form of an addition to a basic dough).
- For example he has three standard paragraphs on baking that tell you
- your rack should be in the center of the oven. Do not spritz the
- electric light bulb etc. This repetitious stuff occupies at least
- half the printed pages of the book - the book thus has the mere
- appearance of heft but is in fact quite thin. (Others may like this
- because you can start at any recipe in a non linear fashion). It has
- no bibliography and is lean on technique. To me the book is more
- sizzle than steak - it is worth reading but owning?
-
- The Italian Baker - Carol Field. In the Joe Ortiz vein. A
- masterpiece on Italian Bread. Carol Field is less authoritative than
- Ortiz in some respects - she is a cook book author with 5-6 published
- books on the history of Italy and Italian foods. Her cookbook author
- roots show through occasionally. For example on page 41 talking
- about yeast she says: "Bakers, who have noses like doctors or
- pharmacists, insist you can cut into the yeast and smell if it's
- right. The really expert say that if you set your ear right next to
- it, you can hear the little "tic-tac" of its growing." While poetic
- this is pure nonsense. Fortunately, there is not much drivel like
- this in the book. The reason I like the book is she tells you what
- the character of the dough is like - wet, firm etc. All too often
- this is ignored in most books on bread when in fact it is one of the
- major ways of controlling the nature of the loaf you produce. The
- minor negative is she repeats mixing information by hand, mixer and
- food processor for each recipe. This is generally unnecessary except
- in some rare cases.
-
- Il Fornio - Author? Light version of Carol Field. In fact owner of
- Il Fornio chain Carlo Veggetti was the person that arranged the
- meetings with regional Italian bakers for Field's own research.
-
- Elizabeth Davids "English Bread and Yeast Cookery". Available in an
- English version with imperial and metric measures and an American
- edition with a conversion to volume based measures (cups vs weights).
- The books is divided into two parts - "History and Background" and
- the second "Recipes". This is an interesting book to a scholar
- because it traces several historical roots of English Bread - it is
- not as some people think an encyclopedia on bread in general. It is
- written in a humanistic style & its virtue lies solely in its
- research into the historical aspects of English bread and breadmaking
- (bibliography of 200+). This aspect of the book makes a fascinating
- read with interesting plates and illustrations.
-
- Its practical utility is a different matter. For example, she has a
- chapter on French Bread, goes on to enumerate the difficulties of
- making french bread and the difference between French and English
- flour and then throws up her hands and says despite all I've said if
- you want to bake French Bread consult Mastering the Art of French
- Cooking by Julia Child et al. ! She then goes on to trace the roots
- of French Bread in England from 1654 to the twentieth century via
- 10-12 historical recipes. Clearly this is aimed at a pedant not an
- amateur. Most of the recipes are historical in nature and make
- interesting reading but it is not a good place to start to learn how
- to bake bread. Please note I am not saying there is nothing of
- practical utility (there is a lot) it is just buried in a lot of
- material. Despite the praise universally heaped on this book (much
- of it is deserved) I feel it has an equal number of deficiencies that
- are glaring. For example, she has a section on Malt, declares she
- hates the taste of it in bread, goes on to say some bakers like it
- for good rises & leaves one thoroughly confused. She neglects to
- mention how and why it works and the distinctions in malt (Malt can
- be diastatic or non-diastatic. Non diastatic is simply added as a
- sweetener, diastatic malt breaks down the starch in dough to yield
- sugars on which the yeast can feed. Having some around in long
- fermented breads is very important). It seems amazing to me that she
- will spend chapters on the "Assize System" & then neglect to tell you
- something of great practical importance. Similarly, her basic recipe
- for bread has almost no mention of kneading at all!
-
- The Breads of France - Bernard Clayton. Bernard Clayton has been
- looked upon as the doyen of American Bread for reasons I cannot
- fathom. The material when published was new and novel.
- Unfortunately, the book is sort of pointless since there appears to
- be no correlation between his description of a bread and the recipe
- that follows. For example, he has a recipe for the famous Poilaine
- loaf (actually describing a bread made by the father of the now
- equally famous Lionel Poilaine), says it is made from whole wheat and
- then uses next to no whole wheat in his recipe! It is therefore
- pointless to buy a book of this sort. His complete book of breads
- has a vast array of recipes again in a boring style. Essentially
- both books are recipe repositories & the recipes are of dubious
- authenticity. The tedium in the Breads of France is relieved by a few
- photographs and vignettes of the bakers or history behind some of the
- breads.
-
- Special and Decorative Breads a two volume set by Roland Bilheux,
- Alain Escoffier, Daniel Herve and Jean Marie Pouradier (Volume 1) &
- Volume II is authored by Alain Couet and Eric Kayser. There is some
- overlap between Vol 1 & II, Vol 1 mainly focuses on traditional
- breads while Vol II has Viennese pastries, Croissants Brioches etc.
- This is a translation of a French original has much distilled wisdom
- and incredible photographs of ornamental and decorative breads. It
- has very concise information that is generally very precise - they
- define the exact hydration for stiff (58-60%) to soft & sticky
- (65-67%) doughs with five intermediate steps. This is useful because
- they either explicitly say the dough is mixed at xx hydration or if
- they use a word like moderately firm you know precisely what they
- mean. Its negative - very specialized all recipes are scaled for a
- professional baker i.e. yield 25-100 lb of dough and major $$ each
- volume is about $70. I am glad I own them but they are so
- specialized that they may not be worth the $$ but it is a very good
- set of books to thumb through if only to improve your presentation.
-
- World Sourdough from Antiquity: by Ed Wood. Out of print (new
- edition in print now - dg) but may be available in some libraries. A
- very cynical view would suggest this book was probably published as a
- marketing vehicle for the starters that he sells through his company
- Sourdough International. A more generous view would be that Dr. Wood
- genuinely wants to spread the sourdough gospel. I do not know what
- motivates him but in fact I feel that the Woods have provided a
- tremendous service to the community by amassing these starters.
- Simply being able to buy a "fast" starter vs a "slow" starter allows
- you to refute the view of Leader or Joe Ortiz that starters are not
- substantially different. The book gives a reasonable explanation of
- several aspects of baking with sourdough. It is probably the best
- book on sourdough for a non technical audience. Treasure trove of
- recipes from Egypt, Bahrain, Saudi Arabia i.e. the area where all
- bread making probably originated (and less interestingly since this
- material is almost universally available, The Yukon, France, San
- Francisco, Austria, etc). He uses a number of grains and flours in
- his recipes demonstrating his awareness of what a true country bread
- is and a certain adventurous spirit with respect to ingredients. It
- has been built up so much on this group that it will probably prove
- underwhelming - it is the best non technical book on sourdough but is
- not necessarily the best book on bread in general.
-
- -Roland
-
- ------------------------------
-
- Subject: 5. What is gluten and how is it developed?
-
- What people call gluten is the formation of linkages between glutenin
- and gliadin. The "development" of dough consists of the formation of
- these bonds. These proteins have SH groups on them than can be
- linked into S-S groups. Just letting the sponge sit allows the
- reaction to proceed which is why the French call this "long kneading"
- i.e. you do nothing and the gluten is partially, developed. This is
- why, in a post to Bruce Hudson on sponge type breads I said that
- dough could be developed mechanically, (by kneading), chemically (by
- mixtures of oxidants and reductants) or fermentatively. Very few
- people realize that you can develop dough in all three ways: they
- learnt kneading was very important and are fixated on it. In fact
- kneading is absolutely essential only for straight dough breads.
-
- Kneading, develops gluten by stretching out the proteins, &
- increasing the rate at which, the molecules collide and the reaction
- occurs. Kneading also forms an ordered cohesive mass. The reaction
- remains essentially, a chemical reaction. The virtue of kneading is
- the mass is very uniform and the gluten can be developed very
- extensively (homogenous and extensive cross-linking) to give very
- strong loaves - which will rise spectacularly and have good
- mechanical strength so you can make free form loaves fearlessly.
- Most straight dough recipes develop all the gluten by kneading.
-
- Many sponge type breads fall into the category where a lot of the
- development is achieved by fermentation which allows less or in
- Jeff's case no kneading. Allowing the gluten to develop by
- fermentation, simply means that you give the dough sufficient time to
- let the chemical reactions occur spontaneously i.e. the linkages will
- form slowly over time. The lattice of cross-linked gluten that forms
- is not necessarily, as strong or as fully developed but this is
- undoubtedly what Jeff is aiming for: French country bread is
- characterized by an uneven crumb - by minimizing mechanical mixing he
- keeps the mass non homogenous. The simple actions of the original
- mixing, punch downs, shaping etc. also add a dimension of mechanical
- development. Relying solely on fermentative development means the
- gluten will not be completely developed, the loaves will be weaker
- i.e. you might have a hard time making a large free form loaf with
- it. By combining some fermentative and mechanical development you
- can dramatically, alter the range of textures of your bread: there
- is an infinite spectrum of how long you ferment and how long you and
- how intensely you knead. By controlling these two you produce
- dramatically, different breads. This is one of the secrets to the
- whole range of "French" breads. Jeff is at an extreme when he uses
- no mechanical development at all. Since he seems to make mainly
- baguettes this is easy to do - you do not need a very strong dough to
- hold its form in a baguette. I would be interested to know if your no
- knead doughs allow you to form large free form loaves.
-
- Several dough improvers including the so called natural conditioners
- like ascorbic acid (Vitamin C, you will see that it is added to
- nearly all commercial flour) are oxidants that facilitate the
- reaction. Similarly, the french add fava bean or soy bean flour
- which has a lipoxygenase which oxidizes flour i.e. takes SH groups
- and make them S-S i.e. forms linkages and also bleaches the
- carotenoid pigments for a whiter crumb. These conditioners have a
- dramatic effect on the rate of the reaction and the extent to which
- the reaction occurs. I learnt this very dramatically, when I bought
- my grain mill: Flour that you buy has been aged or brominated (to
- oxidize the flour which as explained above forms gluten strengthening
- cross links & bleaches the carotenoid pigments). Freshly milled
- flour does not have the benefit of these "improving" i.e. gluten
- strengthening actions. I noticed that my dough would "fall apart"
- when kneading very very quickly. This was because the flour was not
- sufficiently oxidized when freshly milled. This was fixed by adding
- vitamin C and freshly milled soy bean flour (I simply added back
- oxidants! It is still not as strong as the strongest flour I worked
- with. No additions will allow you to turn out a decent loaf too -
- you just need to know how to handle it).
-
- In some commercial, operations the dough is developed by a long list
- of chemicals (check any supermarket bread label) that are essential
- oxidants or reductants and thus facilitate the reaction. This
- combined with a very intensive short 1 min mixing develops the dough
- completely!
-
- Just as the cross-links can form so can they break down. This is
- referred to as the dough becoming "slack" - very long fermented
- doughs become slack because the cross-linking process reverses
- itself. In addition there are a number of chemicals naturally,
- present in dough or from breakdown of yeasts that promote the
- breakdown of the cross-links. This is one of the reasons you cannot
- hold the dough infinitely long in a fermentation to improve its
- flavor. In fact the reason why dry yeast should be reconstituted at
- 104-114 F is because at lower temps the yeast lyse and release
- glutathione which affects the oxidation reduction reactions and
- reverses them leading to slack or weak doughs.
-
- -Roland
-
- See also "http://www.deja.com/getdoc.xp?AN=365738380&fmt=text"
-
- ------------------------------
-
- Subject: 6. How do wild and commercial yeast differ?
-
- The yeasts role in a sourdough starter is to leaven the bread (i.e.
- produce gas). Commercial yeast is very good at this job since that
- is all it was selected to do. Common bakers yeast that most normal
- people have access to is slightly acid sensitive and most sourdough
- yeasts are moderately acid resistant. Commercially on a bakery level
- you can obtain yeasts that are acid resistant and a host of other
- desirable properties (freeze tolerance, sugar tolerance etc.).
-
- In a laboratory environment a common medium for a laboratory form of
- bakers yeast is Yeast nitrogen base whose pH is 5.4! Most sourdoughs
- have a pH at the end of the fermentation of around 3.5 - 4.2. Since
- the scale is logarithmic this is relatively large difference.
-
- The acids produced by lactobacilli definitely slow the yeast down (be
- they commercial or sourdough). The natural yeast are obviously more
- tolerant of acid. You could overcome the acid sensitivity by adding
- more yeast or proofing longer. This is not to say I advocate doing
- it - I am merely pointing out it can be done. You have to be
- judicious in how much yeast you add since too much will cause the
- bread to be overwhelmingly yeasty in flavour.
-
- Another aspect of leavening sourdough breads is that the gluten is
- attacked under acid conditions through the action of several acid
- proteases. Thus the ability of the individual cells of the gluten
- net to hold gas is compromised. If you let your dough develop to such
- a point it will obviously rise very feebly no matter what your source
- of leavening is - wild or commercial since any gas produced will
- simply leak away.
-
- One of the pleasures of sourdough is understanding the rhythms of
- both the yeast and lactobacilli and holding them both at just the
- right level - optimal acidity, optimal flavour (I suspect when most
- people here say they want their bread more sour what they actually
- mean to say is more flavour full - a very sour bread can be
- excruciatingly unappetizing) and optimal leavening. This is achieved
- by manipulating the starter to maximize the number of organisms,
- varying the "wetness" of both starter and dough and controlling time
- and temperature of all stages.
-
- I should point out that if you do play with commercial yeast there is
- a very good chance that you will pollute your starter and you
- obviously do not want to add it to the starter i.e. should you use it
- you definitely need to develop a procedure to maintain the starter
- uncontaminated.
-
- Commercial bakeries oftentimes use yeast as a leavening in a
- sourdough not because they do not know better but because they
- require very predictable rises - they may have hundreds of pounds of
- different breads developing at different rates and have to hit the
- oven in fairly tight windows. A commercial leavening in this context
- can be controlled far easier. Obviously an equal number of bakeries
- develop the bread naturally but this requires more skill, time and
- ultimately for the baker $.
-
- To address the original point of this thread though: a starter made
- from commercial yeast performing better than an established starter
- (I believe Russian from Sourdough International). If I remember
- correctly, the poster mentioned they had obtained the starter second
- hand. Based on my experience with home started vs purchased starters
- I suspect that the starter you obtained is probably far from the
- original sold by SI. I have had the most consistent results with
- legitimate "established" starters.
-
- I should point out however that I have noticed a deterioration in
- some starters over time - I have not figured out the root of the
- problem since I was not careful enough to pinpoint exactly when the
- change occurred but I have found a starter that I loved evolving into
- a dud. Obviously this means contamination/loss of a favorable
- lactobacillus. I was originally very careful when I bought the
- starter and would boil the water used to feed the starter (and let it
- cool!) & once it was established decided it could fend for itself.
- In hindsight I think this may have been an error in judgement: the
- boiling apart from getting rid of any other unfriendly beasts
- probably also got rid of chlorine etc. I suspect that this could
- have been one of the things that did my lactobacilli in. Flour
- obviously has organisms that you cannot get rid of and this is
- potentially another source of contamination: lactobacilli have
- several bacteriophages and produce bacteriocins that could have
- killed my treasured lactobacilli (the reason I think I have lost
- lactobacilli complexity is because the bread rises fine but the
- flavour is middling). The starters from SI have predictably activity
- peaks & the Russian is very fast, you could use this as a test to see
- if what you have is still legitimate. I can vouch for the fact that
- the Russian, Austrian and Bahrain rise as described in their
- literature. Also since the Russian rises so fast you may be tempted
- to bake the bread before the lactobacilli have had a chance to do
- their magic. Among the above three starters I like the flavours of
- the Austrian the best.
-
- -Roland
-
- ------------------------------
-
- Subject: 7. Can I make bread without salt?
-
- Salt is of course very important in a dough. There are several
- proteins in flour that together form gluten during mixing. Some of
- these proteins are more soluble in salt water than fresh water.
- Therefore, addition of salt helps to form a stronger gluten network.
- Commercial bakeries often add salt at the very end of mixing because
- it keeps the dough loose so that it will develop more quickly and
- also does not inhibit the yeast during that brief period. Bread,
- however, can be made perfectly well without salt.
-
- -Troy
-
- ------------------------------
-
- Subject: 8. How do I stop my sourdough bread from flattening?
-
- A very important aspect of making sourdough is the amount of starter
- used in the recipe and how long it has been since the starter
- matured. Typically, about 20-40% of the total flour should come from
- the starter. The higher the percentage of starter, the less proofing
- time it will stand. In other words, if 40% of the flour comes from
- starter, you may only be able to proof 3-4 hours before the loaves
- flatten excessively, depending on the starter and degree of maturity.
- I've never used Carl's starter, but since people like it I assume it
- has fairly low levels of enzymes which make it more tolerant to
- various baking procedures. Different lactobacilli have different
- capacities to degrade flour and to make acid and therefore they act
- differently in bread.
-
- The standard methods to keep bread from flattening excessively
- include reducing water, increasing kneading or adding ascorbic acid
- (100-200 mg per 5 pounds of flour), making sure the starter is not
- overly mature, and doing some of the fermentation as a "bulk"
- fermentation. Bulk fermentation simply means that after mixing the
- dough you let it sit for 2-3 hours at proofing temperature before
- shaping the loaves. That will give the bacteria/yeast time to make
- flavor and gas without having to worry about the loaves flattening.
- Then the loaves are shaped and a final proof of 3-4 hours results in
- a fantastic loaf with a more interesting internal and external
- texture.
-
- One other important reason why sourdough loaves may flatten is that
- the starter is not fresh enough. When you feed your starter use the
- smallest amount of old starter that you can while still getting a
- very active ferment by the time you need to mix your dough. If the
- old starter is very active I would use only 5-10% by weight as an
- innoculum. Starters that are not fresh produce extremely slack
- doughs. The type of flour you use will help, but will not completely
- overcome the problem. If 20-30% of the flour in your dough comes
- from starter you should be able to proof a free standing loaf for
- many hours without flattening. I typically mix a dough, let it sit
- for 3 hours, shape into loaves, and give up to 5 hours of final proof
- with little flattening.
-
- Water content for this type of loaf is 56-60% on flour.
-
- -Troy
-
- ------------------------------
-
- Subject: 9. Can I use chlorinated water with my starter?
-
- No. If you have chlorinated water, dechlorinate it first. The quick
- way is with a carbon filter. You can also boil it or just let it sit
- out uncovered 24 hrs, provided that your water treatment plant
- chlorinates with free chlorine (as ~85% do), and not with the stable
- form of chlorine, chloroamine. This cannot be boiled or evaporated
- out.
-
- Dechlorinated water is not just some yogurt and granola health food
- nut idea, it is very important for the health of your culture and the
- success of your sourdough baking. A microbiologist friend of mine
- confirmed this observation with laboratory techniques.
-
- -Jeff
-
- ------------------------------
-
- Subject: 10. Does temperature of the starter have an effect on flavour?
-
- Sourdough cultures from Europe tend to have many strains of
- lactobacilli. Temperatures under 86 F favor L. brevis which produces
- both lactic acid and acetic acid. Temperatures above 86 F tend to
- favor L. plantarum which is homofermentative and only produces lactic
- acid.
-
- Other factors play a role in the acid profile: degree of hydration
- (soft doughs favor lactic acid formation while stiff doughs favor
- acetic acid).
-
- The way the starter is built up into the final dough will affect the
- absolute number and type of organisms and consequently the flavor
- profile of the bread. German bakers have very complicated schedules
- where they vary both stiffness of the dough and temperatures to build
- their starters and thus alter the flavor of the bread.
-
- I have no idea what organisms are present in the original posters
- culture but if he is lucky playing with temperature and hydration and
- different cultures may allow him to produce the flavor he wants.
-
- -Roland
-
- ------------------------------
-
- Subject: 11. What is diastatic malt?
-
- Malt can be diastatic or non-diastatic. Non-diastatic is simply added
- as a sweetener, diastatic malt breaks down the starch in dough to
- yield sugars on which the yeast can feed. Having some around in long
- fermented breads is very important.
-
- -Roland
-
- Mills will typically put in 1/10% malted barley flour (barley because
- barley malt is cheaper than wheat malt) to provide diastase (enzyme),
- which converts the starch in damaged starch granules to sugars that
- are utilizable by the yeast over an extended ferment. The use of
- more diastatic malt than this can result in slack, sticky dough, and
- will not improve yeast action. Malt is not made from cooked grain,
- but rather sprouted grain.
-
- -Jeff
-
- Diastatic malt powder is powdered malted grain, usually barley, but
- wheat, and rice may also be malted. "Diastatic" refers to the
- diastatic enzymes that are created as the grain sprouts. These
- convert starches to sugars, which yeasties eat. Maltose, a simple
- sugar that yeasties love is usually made in abundance by the enzymes.
-
- Diastatic malt powder is available in some health food stores as well
- as homebrew supply shops.
-
- You can make your own: sprout a cup of wheat berries by covering
- them with water in a jar for 12 or so hours, dump out the water &
- rinse with clean water, and place the jar in a darkish, warmish,
- place. Rinse the berries every day with clean water and return to
- their place.
-
- In 2-3 days they will begin to sprout. When the sprout is as long as
- the berries themselves, dump them out on paper towels, dry them off,
- and set on a cookie sheet in the sun for a day or so to dry out. Then
- put the cookiesheet in a 100F oven for an hour or three. Do not let
- the temp get above 130F or the enzymes will be destroyed.
-
- Then grind the dried malted berries into flour, and use it in your
- favorite recipe at a rate of approx. 1t. per loaf.
-
- I did this for the first time last week, and the bread made with is
- has a lovely wheaty note that was not produced in the past when I
- used brewer's (barley) malt.
-
- -George
-
- ------------------------------
-
- Subject: 12. What is meant by % hydration of a dough
-
- "Bakers Formulae" are based on the weight of flour which is assigned
- 100%. Any other material being added is expressed as a percentage of
- this. Thus water may be at 55% to 60 to 65% of the the flour. If
- you think in metric terms it is very easy each 1000 grams (1Kg) of
- flour would need 600 grams of water for 60% hydration etc, similarly
- salt may be added to 1-2% etc etc. So a bakers % is actually a very
- slippery definition and not "correct" in scientific terms but they
- understand each other.
-
- The % hydration matters both when you feed/build your starter and in
- the final dough. Studies show the maximum acid is built at 90%
- hydration (during feeding/building).
-
- -Roland
-
- ------------------------------
-
- Subject: 13. What is a sponge?
-
- A batter or soft dough containing all of the water, but only part of
- the flour and (usually) none of the salt. The starter (or,
- conservatively, part of the starter) is mixed into it, and thereafter
- it is incubated (at some temperature between freezing and heat death)
- until it gets frothy, at which time the dough is completed with
- additional flour, salt, and usually some kneading.
-
- -Dick
-
- ------------------------------
-
- Subject: 14. What is the difference between 'Classical' and 'Modern' sourdough?
-
- In days of yore, all bread was sourdough. So, it wasn't called
- sourdough unless it was real sour. The way to make it real sour was
- to let a sponge sit for many extra hours, preferably warm.
-
- Many people do that today when making sourdough bread. You can call
- it "souring the sponge". The process favors the acid forming
- bacilli, and lowers yeast activity. If you goof and the yeast
- activity gets too low, you can always throw in some bakers' yeast for
- the final rise. You also can get some rise by blowing the loaves up
- on a hot stone, in spite that a real sour sponge may not have much
- leavening activity.
-
- Denizens of yore had no access to bakers' yeast, nor did they have
- modern bread flours.
-
- Today's bread flours, as well as having uniformly high gluten content
- (typically 13%), also contain diastatic enzymes and dough
- conditioners. The enzymes liberate sugars from starch allowing the
- rise to go on much longer than otherwise would be expected. Dough
- conditioners can have profound effects towards helping the gluten to
- hang together long enough to support a phenomenal rise.
-
- The result is that a kind of modern sourdough bread is now possible
- that the yore people could not have anticipated.
-
- A long rise allows that sourdough bread may be very light, and may be
- baked quite effectively in bread pans in an ordinary oven (without a
- stone). For this bread, a "sweet" (high yeast activity) (sourdough
- yeast, that is) sponge is used. Acidity and flavor which typify
- sourdough bread develop during the rise, not primarily in the sponge,
- as is the the case in the alternative classical method. More and
- more people are doing it this modern way.
-
- But it is not clear to most people that two strategies are under
- discussion here. People on track B should learn how to avoid advice
- from track A people, and conversely. (Advice givers cannot be
- controlled, since a new bunch is born each week.)
-
- How to recognize:
-
- Type A: "Let the sponge proof in a warm place for a long time". "A
- sour (tangy) starter is needed." "Use King Arthur (no additives)
- flour." "Use all purpose flour." "Punch it down (N) times, let it
- double, slash, and toss it on a hot stone." "May be necessary to add
- some dry yeast." (Per most bake books, FAQs here, and sourdough
- packet instruction sheets.)
-
- Type B: Starter is kept frothy, or activated to the frothy stage
- before seeding the sponge. Sponge is developed to the frothy stage,
- no longer. Use bread flour (malted, bromated or whatever). Bakers'
- yeast is never used. Very little or no punching down. Slash (coupe)
- before the rise. Volume quadruples, maybe quintuples, before the
- bake. Special attention needed to avoid deflation if transferred to
- a hot stone (but easy in tins). Special attention is needed to avoid
- drying out during the long rise (which might be 12 hours in a cool
- room).
-
- -Dick
-
- ------------------------------
-
- Subject: 15. How do I make soft buns?
-
- The easiest way to get very soft silky buns is to use lots of pastry
- flour (half pastry/half all purpose or bread) & plenty of fat in the
- form of butter. This produces melt in your mouth types of buns.
- People are generally obsessed with gluten content in wheat - if truth
- be told you can make bread with pastry flour i.e. a gluten content of
- 8% or so. Naturally, the character of the bread is different. You
- generally, want to match the character of the bread with the
- character of the flour. Generally, people are very obsessed with
- high gluten flours which do indeed produce lofty loaves but if not
- worked properly can also produce rubbery loaves. Elizabeth David is
- one of the few authors on bread, incidentally, who advocates looking
- for flavour in flours rather than simply high gluten content - a
- lofty loaf is a good loaf only from certain points of view.
- Incidentally, buns and the like that I have baked with substantial
- amounts of pastry flour have had no problem rising to normal
- respectable levels.
-
- One advantage of high amounts of gluten is the concept of
- "tolerance". Tolerance means ability to withstand abuse - abuse like
- overkneading, overfermenting, overanything. High gluten flours have
- higher tolerance. This means that you have to be slightly more
- skillful in using low gluten flours. I would recommend using a yeast
- dough rather than a sourdough as a starting point if you are going to
- try to make buns with large amounts of pastry flour. The reason is
- you have to be very careful not to overferment this sort of dough and
- it probably easiest to make a straight dough. I have used sourdough
- and got breads as soft as a kiss.
-
- -Roland
-
- ------------------------------
-
- Subject: 16. How should I feed my starter for best results?
-
- Continuous culture of the sourdough starter vs the stop start
- approach of a home baker is really the big difference between a home
- baker and a commercial operation and most home bakers do nothing to
- compensate.
-
- The continuous approach in a bakery is exemplified by the starter
- culture being doubled every 6-8 hours 365 days of the year (almost).
- The home bakers approach is to store the culture and use it
- intermittently and so it is worth examining what exactly happens
- during this storage process.
-
- The notion of the yeast sporulating on storage etc. is virtually
- guaranteed to be wrong for almost all starters. No wild strain of
- yeast can sporulate as is frequently stated in books on sourdough,
- the FAQ etc. wild yeast most commonly are aneuploid or polyploid and
- thus they either do not sporulate or spores have very low viability.
- Also no spore would germinate in the 8-12 hour proof given to it in a
- bread making regimen. Both the lactobacilli and yeast are simply
- dormant in a stored culture and a certain fraction is continuously
- dying as elaborated below.
-
- Both the yeast and lactobacilli are inhibited by the acid produced.
- As you store a culture the organisms die - lactobacilli at acid pH
- die at the rate of 90% a week when stored at room temperature. At
- cooler temperatures the rate is slower (4 weeks needed at 4 degrees
- for 90% mortality). Because the starting culture usually has a large
- number of organisms (in the order of 10E7 - 10E9
- (10000000-1000000000) per gram of dough in an active culture with the
- lactobacilli being higher than the yeast) this very high death rate
- is not immediately perceived - the culture is progressively
- enfeebled. At neutral pH the death rate is slower (incidentally this
- is the logic why you feed and proof your starter for a very short
- time before you return it to the fridge - the proteins in flour
- neutralize some of the acid improving survivability and all the
- nutrients are not depleted so the culture can grown at a slow rate in
- the fridge).
-
- If you do not use a culture continuously but store a culture in the
- refrigerator over time only 10%, 1% or less of the culture will be
- alive depending on how frequently you use it, what the acidity of the
- culture was when you stored it etc. Simply, feeding the culture
- with a equal volume of flour water does not bring the number of
- lactobacilli up to the maximum number possible - a two fold dilution
- does not really relieve the acid inhibition adequately, and instead
- of 10000000 organisms/gram you may have only 1000000 or less. The
- culture is thus never really vibrant - it is simply limping along.
-
- What I do therefore is to do a very large dilution when I pull the
- starter out of the fridge say 1/2 to 1 tablespoon to 1/2 cup flour
- and a similar amount of water. This dilution relieves the acid
- inhibition and allows the culture to actually divide and grow back
- towards the maximum possible. 12 hours later I refeed (doubling the
- starter) and repeat this until I have the amount of starter I want
- built up. I always try and adjust this so that there are at least a
- few doublings of the starter before I actually incorporate it into a
- dough. I have used starters from Sourdough International exclusively
- so cannot comment on the success of this approach with
- non-traditional starters (i.e. anything that is fed on something
- other than flour and water). This regimen gives a starter with
- excellent properties, with respect to souring, leavening etc. This
- is slightly more work than most people usually do but you will be
- rewarded by an improvement in flavor, dough characteristics, etc.
-
- -Roland
-
- What is good feeding? I believe that there are two important things:
-
- First, don't starve the culture. This means that you should feed the
- culture once it shows evidence of strong activity (frothing or rising
- depending on the thickness of the starter) and not too long after
- that. If you feed too infrequently the cell populations in the
- starter will begin to decline due to starvation, etc.
-
- Second, feed the starter by quadrupling (or even quintupling). This
- means that you feed the starter three times it's weight each time you
- feed it (i.e., if you have 2 oz of starter, feed it 6 oz of new
- food). If you don't have a scale you can do the measurements by
- volume, but I think weight is better. I also think that it is best
- to keep the starter at a relatively thick consistency. Both the
- dilution at feeding and the thick consistency are designed to
- encourage the presence of certain good lactibacilli. FYI, when one
- feeds by such extreme dilution, it is not necessary to maintain a
- partiularly large amount. Starting with a tablespoon of old starter
- and mixing this with a quarter cup each of flour/water at each
- feeding will leave you with a sufficient amount of starter.
-
- -Sam
-
- ------------------------------
-
- Subject: 17. Are all starters the same?
-
- No. I think starters are different, a good starter should be
- treasured. Fortunately, the very valuable work of Ed Wood makes it
- most simple to prove. All you have to do is to try the Russian or
- another "fast" starter from Sourdough International vs a slow starter
- from them. The behavior of these starters is very very different
- with respect to rate of leavening, and ultimate levels of acidity
- produced and anybody willing to spend a few $$ can verify this. I
- also think that starters are discernibly different with respect to
- flavor. In fact the classical San Francisco sourdough does have a
- signature flavor that no other sourdough I have tasted resembles (I
- do not have the SI San Francisco culture so do not know how their
- version of it behaves with respect to the signature flavor).
-
- I am also skeptical of grape based starters, etc. I know Nancy
- Silverton and other celebrated bakers advocate this but I can see no
- logic in it. Grapes indeed have yeast and lactobacilli on them. The
- problem is these particular varieties of yeast and lactobacilli have
- never been recovered in any sourdough starter that has been examined
- from any place in the world. These organisms are undoubtedly
- specific to grapes as certain other lactobacilli are specific to
- yogurt. There are hundreds of strains of yeasts and equally large
- numbers of lactobacilli. These organisms develop niches where they
- thrive. To transplant an organism from one natural environment to
- another is not a formula for success. It is like taking a polar bear
- and putting it in the desert. There are hundreds of cheeses made
- based on very small differences in starter cultures and processing.
- These people are undoubtedly celebrated bakers but to them a yeast is
- yeast and a yeast on a grape is a "wild yeast" and they have no
- understanding of any of the nuances. I do not claim to know what
- exactly is resident in their starters and whether any organisms they
- introduce from the grape actually survive and are viable over time
- (years as opposed to weeks).
-
- -Roland
-
- ------------------------------
-
- Subject: 18. What about Nancy Silverton's latest book?
-
- or 'Stalking the Wild Yeast'
-
- Ringo is, I think, a fine drummer, my household plumbing is a
- masterpiece, and all those ice-skaters on TV twirl great. The less
- you know about some craft, the less critical you are about its
- practice.
-
- Of course, the more you know, the more judgmental you are. I've been
- working at sourdough bread baking for a decade; and it has taken me
- that long to fight through the misleading sourdough lore. Separating
- useful techniques from superstitious ritual has been tough. Standard
- bread books are either full of falsehoods ('Beard on Bread' is a
- particularly bad example) or misleading and hazy.
-
- So I finally get it right, right enough to be able to teach others,
- and what happens? Nancy Silverton publishes 'Breads from the La Brea
- Bakery', (Villard, 260 pages, $30), a book that really gets it right,
- is clearly written and has an abundance of clever recipes that I
- wouldn't have come up with in another 10 years.
-
- Her sourdough creations cover an enormous range: Country White,
- Challah, Walnut Bread, Olive Bread, Chocolate-Sour Cherry, Pretzels,
- Raisin Brioche, Focaccia, Normandy Rye, Izzy's New York Rye,
- Whole-Wheat Boule, Potato-Dill and on and on. This is not just a
- great book on sourdough, it is the only book -- an artisanal well of
- information and guidance in the craft of great bread baking. When
- much store-bought bread is factory whipped wheat candy, when bread
- machines are a commodity item, when real bakers are only just
- beginning to make a comeback in some urban areas (and even in
- Carrboro), it is solace to possess such a valuable 'vade mecum'.
-
- It is sad though that we need such a book. In a well-ordered world,
- good bread is no further away than the nearest baker. Only in recent
- years have we in Triangle had good bread available at all. Even in
- Paris, where bread and pastry is traditionally left to the
- professional, a glossy magazine recently lamented the decline of
- decent bread and the rise, so to speak, of factory breads sold in
- "bakeries"; more astoundingly, it heretically offered instruction on
- how to make good bread in the Parisian home.
-
- Although Silverton's directions are clear and superbly organized, the
- multi-step, 2-3 day procedures may at first look overwhelming. (See
- page 58 for Silverton's hints on time-efficient ways to make bread.)
- After a few practice loaves things will get simpler, and you be
- rewarded with great bread. Leavened bread is a simple food that has
- been around since at least Egyptian times, and its basics are simple.
- That's what makes the achievement of great bread such a fascinating
- exercise. Flour, water, salt, beasts (bacilli+yeast) and time are
- bread's basic ingredients.
-
- Salt is crucial for both taste and texture. Good quality sea salt is
- a nice luxury. High quality flour makes a surprising difference. For
- basic bread baking (sourdough or otherwise), a good all-purpose,
- unbleached, unadulterated flour is called for. In the Triangle area,
- the most easily available high-quality flours are King Arthur
- (Hannaford's has it at a reasonable price) and Lindley Mills flour, a
- local product carried by both Wellspring and Weaver Street.
-
- Beasts. I say beasts because the defining characteristic of a
- sourdough bread is that its leavening is a symbiotic culture of
- lactobacilli and wild yeast. "Wild yeast bread" might be a better
- name, since "sourdough" has led some to think that the sourer the
- better; like those who rank peppers or Indian restaurants by how hot
- they are. Bread made from a flour, water and commercial yeast slurry,
- let to mature for two hours to a day, is not sourdough. That
- technique and its variants is called in France 'poolish', in Italy
- 'biga', and, in American, 'the sponge method'. It is a very very good
- way to make bread. It is not sourdough.
-
- Sourdough cultures contain wild yeasts and certain friendly, i.e.,
- symbiotic, lactobacilli. The symbiosis is manifold and complicated:
- the bacilli produce lactic acid (a 3.5-4.2 pH environment) that its
- companion yeast can thrive in, but in which commercial yeast dies;
- produce antibiotic agents that are hostile to other organisms; and
- metabolize maltose, which wild yeast cannot. The biochemistry is
- quite complicated and a far cry from the oversimplified picture of
- yeast as a mere belcher of gases. If that's all yeast, or sourdough
- cultures did, then there would be a lot more good bread around than
- there is!
-
- It is possible to make your own sourdough culture. The underlying
- idea is to start with flour and water and, one way or another, let it
- sit until a stable culture develops and then feed it into health. The
- Silverton book has good, though intimidatingly long, instructions. It
- is much simpler and surer to buy a culture from a reputable source;
- it is fortunate that there is one. An obsessive guy named Ed Wood
- travelled the world collecting old sourdough cultures from
- multi-generational bakeries and worked out a way of drying them for
- resuscitation. Sourdoughs International (PO Box 670, Cascade, Idaho
- 83611, (208)382-4828, fax: (208)382-3129])carries cultures from
- France, Austria, Bahrain, Russia, San Francisco, Egypt, Saudi Arabia
- and Yukon.
-
- SIDEBAR
-
- The basic bread process
-
- Preparation, Mixing, Kneading, Fermentation part one (first rise),
- Fermentation part 2 (proofing), Baking, Letting Cool.
-
- The above sequence is, of course, a standard bread making sequence.
- The sourdough part is buried in "Preparation". Sourdough starters are
- built up in stages. For home baking, where the culture may go a week
- or two between uses, this is particularly important. (In traditional
- bakeries the 'chef', a lump of dough from the day's bake, starts the
- next day's starter.).
-
- The stored 'chef' is taken out of the refrigerator and coaxed back
- into life with a series of additions of water and flour, roughly
- doubling the amount each time. The staged feeding keeps the increase
- in yeast and bacilli in correct proportion. Then the dough is made
- from a portion of now vigorous starter.
-
- One item that people used to commercial yeast might overlook is
- temperature control. The starter and dough are best at under 80
- degrees F. Your flour will be at room temperature and kneading will
- add about 10 degrees. There is also about twice as much flour as
- water, so your cold (dechlorinated) tap water will almost never be
- too cold! And in the summer, you will need ice cubes.
-
- Kneading develops the gluten (gluten is a protein in the endosperm of
- wheat which, given the right conditions, forms itself into long
- elastic strands that give bread its cellular structure -- the
- "pockets" that hold the gases that give baking bread its loft) and
- introduces the necessary oxygen. After rising in baskets, free-form
- loaves are turned onto peels and slid onto hot stones in the oven.
- All breads need to rest, uncut, after coming out of the oven. There
- is still stuff happening in there.
-
- A well made sourdough will keep from 4 days to a week on the counter,
- wrapped in a towel or in a paper bag. Refrigerator temperatures
- hasten staling, and plastic promotes mold and destroys crust.
-
- -David
-
- ------------------------------
-
- Subject: 19. How do I get that great crust?
-
- It is difficult to reproduce the effects of a commercial hearth oven
- at home. The properties of a good oven include thick baking stones on
- the bottom preferably heated with gas fire for more even heat
- distribution than electric coils. The oven should have heating
- elements at the top of the oven and controls for setting the heat
- intensity in all areas of the oven.
-
- The most important difference between baking bread in a commercial
- hearth oven and at home, is that the commercial oven has steam tubes
- which deliver large amounts of steam at a reasonable pressure. Steam
- gelatinizes the starch and protein on the exterior of the loaves
- without forming a hard shell. After the steam is removed, the
- gelatinized layer dries out forming a thick crunchy crust. With no
- steam, it is more difficult to keep the exterior of the bread from
- forming a paper thin shell.
-
- Another important difference is that the commercial deck oven is not
- very tall from top to bottom which makes the heat more intense than
- in a home oven. The thickness of the baking stones also acts as a
- heat sink to deliver maximum heat to the bread before the crust
- begins to form resulting in better volume. In a home oven, a thin
- layer of steam surrounds the bread and prevents efficient transfer of
- heat to the bread. Convection ovens work better.
-
- A few things can be done at home to better simulate a true deck oven.
- Get a good thick baking stone and of course put it in the oven long
- before you intend to put bread on it. Put the stone as close to the
- top of the oven as you can still leaving room for the bread to rise.
- That will give more intense heat. To simulate quality steam, spray
- the bread well with water just before baking. I use another strange
- gadget that works very well. I take aluminum muffin tins and poke
- tiny holes in the bottom of each well. I fill the tins with boiling
- water and place them on the bottom rung of the oven about a minute
- before putting the bread in to develop initial steam. The water will
- drip onto the bottom of the oven and create steam. Remove the tins
- after the first 5-10 minutes or the bread will develop an undesirable
- crust. Also, I heat my oven about 50 F higher than i need because
- the water evaporation cools the oven. Depending on the oven this
- method works pretty well.
-
- -Troy
-
- ------------------------------
-
- Subject: 20. How much starter do I need to keep?
-
- I think the important point in the Silverton procedure is to
- frequently feed the starter so that it as active as humanly possible.
- I think she committed a major screw up by stressing the volumes so
- much. Thus it would be perfectly OK to start with 1/2 a teaspoon of
- starter and add 1/2 teaspoon water and flour and on the next feeding
- double this to one teaspoon, then two teaspoons, 1/4 cup, 1/2 cup etc
- until you have the amount of starter that you need for your recipe
- and a little extra to store. The doubling procedure is standard
- practice in most sourdough recipes but there is no law saying you
- have to double. In fact, some German recipes start with a massive
- dilution (one in 100) for the first feeding and then use the normal
- doubling until the required amount of starter is built up.
-
- A single teaspoon of active starter (or starter stored for a few
- weeks at most in the fridge) will have tens of millions of
- yeast/lactobacilli. It is thus not difficult to rebuild the starter
- from seemingly vanishingly small amounts. A thick head of bubbles
- will tell you that you starter is chugging along. Of course this
- assumes you have a good starter to begin with - if you do not have a
- decent starter then the frequent feeding regimen recommended by
- Silverton will rapidly lead to death of your starter(?) because there
- simply were not enough organisms to double at the same rate at which
- you feed them.
-
- The important point if you start with small volumes is that the
- starter can dry out relatively easily - you have only 1/2 teaspoon or
- one teaspoon of water to evaporate in the early steps. Thus you
- should take steps to ensure that the starter does not dry out - make
- it a bit more wet than normal, for the first few feedings cover it
- with a wet towel or place it in a glass which in turn is placed in a
- rubbermaid container filled with a little water. In the cold weather
- I use small coolers that I fill with water at the right temperature
- (85F) and then float my starter on rubbermaid boats in there - this
- serves as an incubator and also keeps it relatively humid.
-
- I am astounded that a celebrated chef like Silverton could suggest a
- recipe that would end up with 7 pounds of starter that you have no
- use for! This convinces me that all cook book authors seldom
- actually test their recipes or check for appropriateness for their
- audience - Silverton's recipe would be fine for a bakery but
- ridiculous for the average Joe or Jane that the book was written for.
-
- -Roland
-
- ------------------------------
-
- Subject: 21. Sourdough Science 101 or How are the sourness and
- leavening of starters related?
-
- Don't let the subject scare you off. My kids tease me that since I
- left teaching (biology among other subjects), I have to find other
- people to listen to me. They are the usual targets. I'll try to be
- gentle - and practical.
-
- There have been several posts over the last little while asking the
- same question in different ways - how are the sourness and leavening
- of starters related? Some starters seem too sour, or not sour
- enough, or have lost their sourness, or are sluggish or too active
- (not a problem for most) and folks want to know how to manipulate
- this. It also has been pointed out that lactobacilli are anaerobes,
- but this needs expansion. Here are some thoughts on this.
-
- I am a homebrewer, and have read a good bit about yeast growth.
- Baking and brewing yeast are just different strains of the same
- species, but wild yeasts are different species, and some are even
- different genera, so this may not apply to all, but I suspect it does.
-
- Cultured yeast needs oxygen to reproduce, so once it has depleted the
- oxygen in a starter/sponge/dough, it has pretty much reached the
- population it's going to have. After this, it shifts its metabolism
- to anaerobic. Assuming that wild yeast are much the same, this
- means that letting a starter or sponge sit longer is not going to
- result in much more yeast, and therefore will not increase its
- leavening power. It will become more sour (see below).
-
- Lactobacilli are facultative anaerobes (as opposed to obligatory
- anaerobes), so they will continue to metabolize and reproduce *either
- with or without oxygen*. However, they only produce lactic acid once
- the oxygen is depleted, resulting in a more sour starter/sponge/dough
- the longer you let it sit. I don't think you need to worry about
- excluding air - the surface above the sponge or whatever is full of
- CO2 from the yeast, so very little oxygen is going to diffuse into
- the sponge, especially if you have it covered, and this will keep it
- from drying out, too. Of course, during this time, the gluten will
- deteriorate the longer you let it sit.
-
- What does this all mean? If you want a maximally active culture,
- whip all the air you can into it each time you build it. I add the
- water first and whip this thin batter to a froth with an electric
- mixer, then mix in the flour. This results in maximum yeast
- reproduction. Then, as soon as it has used up all this oxygen, I
- build it again. Of course, it's hard to tell just when this is, but
- I generally let a sponge go until it just begins to fall. If you
- want a more sour bread, let either the starter/sponge/dough go
- longer. I find that with high protein flour such as bread or hard
- whole wheat, the dough can withstand two full rises before shaping
- into loaves, resulting in more flavor (not just more sourness, but
- that, too).
-
- I hope this little science lesson has practical benefits to your
- bread baking. If anyone knows more details about how wild yeasts and
- lactobacilli interact, I'd welcome hearing it, especially if I'm
- wrong. I suspect the symbiosis of some cultures may change things,
- but this works with my Poilane (originally) starter.
-
- -Jeff
-
- ------------------------------
-
- Subject: 22. What is the Microbiology of San Francisco Sourdough?
-
- Several studies have been conducted on the natural microbiological
- flora of sourdoughs from around the world. In terms of understanding
- the basis of the symbiosis between yeast and lactobacilli the most
- successful studies have been by Sugihara and colleagues. Despite the
- existence of several varieties of yeast and lactobacilli they showed
- that the dominant yeast was a non spore forming variety of
- Saccharomyces exigus called Torulopsis holmii and now reclassified as
- Candida milleri sp. nov. The dominant lactobacillus was a new
- species christened Lactobacillus sanfrancisco sp. nov.
-
- Yeast and bacteria occur in a ratio of 1:100. The unique symbiosis
- is explained thus: Though most strains of yeast can metabolise the
- sugar maltose Candida milleri cannot. Dough abounds in maltose which
- is a released from "damaged starch" through the action of amylase
- enzymes. Thus maltose is freely available to the lactobacilli which
- have an absolute requirement for this sugar and they cannot utilise
- other sugars present in dough. The yeast can utilise all other
- sugars present in dough thus the two critters do not compete for a
- carbon source. In addition, the lactobacilli have an enzyme maltose
- phosphorylase which while assimilating maltose releases glucose into
- the media to give the yeast a small boost.
-
- The lactobacilli also secrete an antibiotic cycloheximide which
- "sterilises" the dough since it kills many organisms but of course
- Candida milleri is resistant to cycloheximide.
-
- Lastly, Candida milleri is moderately tolerant to the acetic acid
- which the lactobacilli produce. I should also note that the
- nutritional requirements of the lactobacilli is complex - they
- require a number of amino acids and fatty acids which may be derived
- from dead yeast cells.
-
- Spicher in Germany characterised German sour rye. He found the
- dominant yeast species were Candida krusei, Saccharomyces cerevisiae,
- Pichia saitoi and Candida milleri. The Lactobacilli included L.
- brevis, casei, fermenti, pastorianus, bucheneri, delbrueckii,
- leichmannii, acidophilus, farciminis, alimentarius, brevis
- var.lindneri, fermentum, fructivorans and Pediococcus acidilactici!
- (This zoo of organisms present naturally in Rye flour is the reason
- why it is so easy to start a good sourdough culture from rye for
- example see "manuels starter" in the Laurel's Kitchen bread book.)
-
- Pure culture studies showed that he could reconstitute a starter that
- was close to the original with the yeast Candida krusei and
- Lactobacillus brevis var. lindneri. The basis of the symbiosis is not
- well understood to the best of my knowledge but is probably similar
- in principle to the one described above for San Francisco sourdough.
-
- On a final note, I should point out that pure cultures of
- Lactobacillus sanfrancisco are grown on defined media, harvested and
- freeze dried and supplied to bakeries around the world to make
- instant sourdough!
-
- Should there be sufficient interest in this sort of information, I
- can post periodic updates on the scientific lore of breadmaking.
-
- -Roland
-
- ------------------------------
-
- Subject: 23. What about Ed Wood's latest edition of his book?
-
- Ed Wood's new edition of his authoritative book on sourdough,(World
- Sourdoughs From Antiquity, Ed Wood, 1996, ISBN 0-89815-843-5, Ten
- Speed Press, $16.95 paperbound, approximately 9" x 7") is an
- attractive book, well laid out, with 185 pages and 8 pages of colour
- photos. Some of the colour photos could be helpful to the novice in
- learning some of the techniques of bread making. Other colour photos
- are from the National Geographic project on ancient sourdough and are
- interesting for their historical content.
-
- The book opens with Ed's experiences in investigating with others on
- a team how man made his first leavened bread in Egypt, a project
- supported by the National Geographic. These experiences and
- discoveries were the subject of an article in National Geographic in
- 1995.
-
- Ed continues with an expert and thorough introduction to sourdough
- cultures, their care and feeding, theory, and of course, the making
- and baking of sourdough bread.
-
- The book has a good index and around 120 pages of a wide variety of
- interesting sourdough recipes, roughly one recipe per page, of
- standard and exotic breads, together with pancake and waffle recipes.
- This makes for a good book to have on hand both for the novice
- learning and the experienced sourdough hand looking for something
- different.
-
- There is also a chapter on baking sourdough in bread machines.
- However, I agree with Ed that making sourdough in bread machines
- involves more art than science. No bread machine on the market that I
- know of is really designed for sourdough.
-
- Ed's company, Sourdoughs International, which sells sourdough
- cultures, is on the web, and contact information is at
-
- -Darrell
-
- ------------------------------
-
- Subject: 24. How can I start a starter from scratch?
-
- I'm puzzled why starting a starter presents a problem to many people.
- It really is an extremely simple procedure. I often forget to hold
- back some starter from a dough, so I wind up baking the whole lot and
- I'm left with no starter to continue, and I have to regenerate from
- scratch again. This is an inconvenience, not a disaster! Perhaps I'm
- a little careless here, partly because it's so easy to do. In the
- hope that it might be helpful to others, here are my thoughts on the
- matter:
-
- - Firstly, forget everything you ever heard about catching
- yeasts "from the air." Yes, there _are_ yeasts - and lactobacilli -
- in the air, but from a practical point of view it is important to
- note that there are far more of them already present in flour! In a
- cup of flour we're talking millions of them. So the good news is that
- you already have the yeasts and bacteria you need, right off the
- supermarket shelf, the bad news is that you also have mold spores and
- other bacteria which aren't so desirable. Fortunately, given the
- right conditions the yeasts and lactobacilli quickly dominate and the
- starter becomes too acidic for the other organisms to survive. The
- microorganisms are not destroyed (though they are probably
- diminished) by bleaching so can happily get a starter going from
- normal store flour. However, since they are more plentiful on the
- surface of the grain, a wholemeal flour is the easiest (quickest) to
- get going.
-
- - Remember that the sourdough microflora require food, moisture
- and the correct temperature. You provide food from flour. Rye flour,
- because it contains more sugars than wheat, provides more quickly
- available food, so for this reason it is easier (i.e. quicker) to get
- a sour going. Also, whole grain flour contains more proteolytic
- enzyme and amylase (which exist in higher quantities just under the
- surface of the grain), so again the food source is richer and the
- sour is quicker to get going. The most important point to remember is
- to feed regularly. For a beginning starter you need to feed every 24
- hours. At the first feed, you probably will not notice much or any
- activity, except perhaps a slightly winey aroma (especially if you
- use rye). Never mind: feed anyhow. I suspect this is where most
- people go wrong - figuring that leaving it a few more days will get
- it going! In reality, the yeasts are running out of readily available
- food so they are less active, while the molds and other 'off'
- bacteria continue to multiply, so you wind up with a slimy goo. By
- the second or third feed the starter will be bubbling nicely. By the
- fourth or fifth feed it will be adequate to bake with, but it will
- continue to develop for a few more days.
-
- - Temperature should be 70-80F ( 20 - 25C ). You could go warmer
- than this, but you would then need to feed more often; also, the
- nature of your sour would be different, less desirable for a good
- loaf.
-
- - Moisture comes from water which you add with the flour. I use
- 50/50 by weight, which by volume is approximately 1/2 cup water per
- cup flour. You don't need to be too precise, so volumetric
- measurement is fine, and simple. You can use a more liquid starter,
- but you will have to feed more often. [I've seen various discussions
- about tap vs bottled water, and tap water works just fine. I suppose
- if you live somewhere that has outrageously high chlorination it
- might be different, but in general if you choose bottled water you do
- so for your own health, not the health of the starter!]
-
- To put it all together: Take 1/2 cup flour (preferably whole meal
- rye), mix to paste with 1/4 cup water in a 1 cup size container.
- Cover and leave for 24 hours at 70 - 80F. Throw away half of the
- mixture, and refresh with another 1/2 cup flour and 1/4 cup water,
- cover and leave for 24 hours as before. Repeat. By now, the starter
- should show bubbles. If using rye, start using regular white flour
- after the third or fourth feed. Now you have a starter which you keep
- alive indefinitely by regular feeding.
-
- Happy baking.
-
- -Jonathan
-
- From: JJohn90282@aol.com
- Date: Thu, 3 Aug 2000
-
- I was just looking at your article about sour starters. Lots of hard to find
- Info. Just one thing I would like to add is the use of organic flours. Gold
- Medal has an organic white flour in most of the stores around here, Portland,
- Oregon. Try mixing 2 cups of this flour with 2 cups filtered water. This time
- of year the starter can used in about 8 hours, or less. It's almost
- unbelievable.
-
- -Jim
-
- ------------------------------
-
- Subject: 25. How do I get holey, sour, moist and long keeping bread?
-
- I get the most moist dough and most irregular holes when I have the
- most over mature dough. Unfortunately, this also correlates with
- lower loaf volume and more slump. However, if you look at the loaves
- pictured in French Specialty and Decorative Breads (or whatever the
- title is, I've lent out my copy), you will see that the bread
- fermented with old dough is like that - fairly flat round loaves, and
- that wonderful texture I seem to get most often when something goes
- wrong.
-
- As far as allowing the dough to "proof" (I'd use the term ferment, or
- rise) for a few hours before shaping, that is my standard operating
- procedure. I usually let it at least double twice (punching down in
- between).
-
- So, in general, if I always go to the next stage (starter to sponge
- to dough to loaf) when that stage is at maximum volume, I get less
- sour bread with more "conventional" texture. The more I let the
- stages go, especially the dough stage, the more holey, sour, moist
- and long keeping the bread is.
-
- - Jeff
-
- An irregular crumb is achieved with an extensible dough. This is most
- easily done using a "weak" flour. French bread flour (type 55) has a
- protein level which is extremely low by US standards (9 - 10 % vs
- 12%+). Using a weaker flour, highish hydration (65%+) and short
- mixing time is the surest way to get good irregular crumb, and don't
- shape your loaves too tightly. But don't expect enormous holes, as in
- ciabatta, unless you to extreme hydration. Of course, the lower
- protein flour will have less tolerance than a normal US bread flour,
- so be careful not to overproof.
-
- - Jonathan
-
- ------------------------------
-
- Subject: 26. Is slashing of loaves aesthetic or functional?
-
- Both.
-
- Historically, French rural ovens were communal, in a sense: they were
- originally owned by the lord, and maintained by a fournier, or
- ovenmaster, who kept the oven hot but charged for its use. Since the
- bread of each household would be mixed with others in the oven, a
- distinctive slash was one way to tell the loaves apart. After the
- feudal power of other lords (and the Church, which also controlled
- many ovens) was broken, the ovens were (and are, in places like
- Bugey, in Eastern France) owned by the "commune", the governmental
- body of the city or district. The are still used on holidays, and the
- bread is still distinctively slashed.
-
- Anyway, bread which is not baked in a pan and which is not proofed in
- a 100% humidity environment will almost always burst as it is baked,
- and the burst is uncontrolled and messy. The slash controls this,
- but is also decorative - it enhances the vitality of the process...
- as the burst shows how well the baker matched the rising power of the
- leaven to the mechanical properties of the gluten. A nice slash and
- shred is a sign of proficiency in baking.
-
- Whole grain breads that do not rise or spring as markedly do not need
- to be slashed if they are proofed in a high-humidity environment.
-
- -Dan
-
- Additionally slashing prevents a "flying crust." Flying crust is a
- term describing the lifting of the entire upper crust of a loaf
- during baking to form one large bubble.
-
- Darrell
-
- ------------------------------
-
- Subject: 27. How do lactic bacteria affect sourdough bread?
-
-
- 13 Feb 1997 10:49:32 +0100
-
- Dear Daniel Wing!
-
- Your letter to Prof. Hammes has reached Hohenheim, and Prof. Hammes
- has asked me to take care of the communication. I am a Ph.D.
- candidate in Hammes' lab working on the physiology of sour dough
- lactobacilli.
-
- Please feel welcome to address questions to us concerning sour dough
- microbiology and technology! I will mail two recent publications or
- our lab concerning the physiology of sour dough lactic acid bacteria
- by mail, but as they may take a week or longer to reach you, I will
- give a few comments on the questions in your letter:
-
- - yeasts do not produce appreciable amounts of either lactic or
- acetic acids, their main metabolites are ethanol and CO2. If
- acidification of the dough is desired or required (e.g. if rye flour
- is used), lactic acid bacteria or organic acids (most commonly lactic
- or citric acids) are added.
-
- - homefermentative lactic acid bacteria do produce solely lactic acid
- from maltose or glucose under anaerobic conditions (as they are
- prevailing in sour dough fermentations). Thus, doughs acidified with
- homofermentative lactic acid bacteria (LAB) contain but little acetic
- acid. As homofermentative lactic acid bacteria do not produce CO2,
- yeast must be added to ensure leavening of the dough.
-
- - In sour doughs with a tradition of continuous propagation (such as
- the San Francisco French Bread Sour Dough process, German rye sour
- doughs or sour dough employed in Pannettone production in Italy),
- heterofermentative lactobacilli, especially L. sanfrancisco, are
- dominating the fermentation. Heterofermentative lactobacilli produce
- lactate, ethanol, and CO2 from hexoses (most strains do not ferment
- pentoses), HOWEVER, if additional substrates are present that serve
- as electron acceptor to balance, acetate is produced instead of
- ethanol. I do not know whether or not you are familiar with the
- concept of the "redox balance": Degradation of hexoses via the
- pentose-phosphate pathway as employed by heterofermentative LAB
- results in phosphorylation of ADP to ATP, and in the reduction of NAD
- to NADH. As there is no use for NADH, it must be oxidized to NAD
- again. In the absence of other substrates, acetyl-Phosphate is
- reduced to ethanol, with two NADH becoming oxidized to HAD in the
- process. If either fructose, oxygen, citrate or malate are present,
- these become reduced to mannitol, H2O, lactic and acetic acid, and
- succinate, respectively, and acetyl-P is dephosphorylated to acetate.
- (This explanation may not be very straightforward, I hope we did a
- better job in the publications I`m about to send you; these also
- include a diagram showing the metabolic pathways of L. sanfrancisco).
- The consequence for the molar ration of lactate:acetate (fermentation
- quotient, FQ) in sour dough fermentations is, that acetate in
- produced only if one or more of the above mentioned co-substrated is
- present. Oxygen is present only in the beginning of the fermentation,
- and the amounts of oxygen are too low to result in significant
- amounts of acetic acid, though, in principle, it is possible to
- increase the acetate content by aeration of dough. Fructose is
- present in sucrose and other glucofructans with higher molecular
- weights. Fructose is released from these compounds by cereal or dough
- enzymes (many strains of L. sanfrancisco don`t even cleave sucrose)
- and consequently reduced to mannitol by L. sanfrancisco. The ration
- of mannitol : acetate in sour dough fermentation is approximately
- 2:1, suggesting that fructose is the most important electron
- acceptor. Furthermore, citrate and malate are present in the dough in
- amounts less than 10 mmol/kg, these are utilized also.
-
- Thus, the effect of substrates and oxygen on the FQ is nicely
- explained by the metabolic characteristics of the dominating
- fermentation organisms. Dough yield (=kg dough per 100 kg flour) and
- temperature also influence the FQ. Spicher reports that softer doughs
- lead to an increased FQ; an increase in temperature results in higher
- amounts of lactic acid, while the amount of acetic acid remains more
- or less the same, thus, the FQ is increased again. I do not have a
- straightforward explanation for these phenomena, but changes in dough
- yield and temperature will result in changes in buffering capacities
- of the dough, modified activities of cereal and microbial enzymes, as
- well as a changed ration of yeasts : lactobacilli counts, all of
- which are likely to influence the FQ.
-
- Yours
-
- Michael Ganzle
-
- --
-
- Dear Michael Gaenzele
-
- Thank you for sending one of the most gracious letters I have ever
- received in response to any kind of an inquiry. Since I wrote to
- Prof. Hammes I have been able to copy a number of articles from
- English language publications by Drs. Brummer, Spicher, Vogel, and so
- forth. Unfortunately, some of them have been in non-technical
- journals and were thus short on details, and even the less technical
- ones were not as clearly and idiomatically written as your letter. I
- DID have a hard time understanding what was meant by Dough Yield, for
- instance, although I had figured it out before I got your letter. I
- am still not sure I understand some of the statements those authors
- made about the acid content of doughs (such as the units of
- measurement), but I have been piecing things together by looking at
- all the articles cumulatively. Your letter has clarified a great
- deal. I will put stars next to my current questions to make THIS
- letter easier to answer. Like this *.
-
- One problem for me was that I did not realize how predominant rye
- flours were in German sourdough baking. I know that typical rye
- pentose is about 8% and that pentose viscosity is important in
- gas-trapping in rye doughs (He and Hoseney, 1991) but I still don't
- know how an acidified rye dough behaves differently from a more
- neutral one. *Does it affect viscosity somehow? He and Hoseney
- studied neutral doughs only.
-
- I also do not understand why Brummer says "Anstellgut" is a
- non-translatable term. *What do you think it translates as? *I take
- it that this a very ripe starter, very acid, maintained at room
- temperature at some infrequent rate of refreshment? *Is it always rye
- based? *Always a high-ash flour? *How is it different from the type
- of French and American wheat starters that are refreshed 1:1 every
- eight hours, or 1:4 every 12 hours? *What is its consistency, pH,
- Total Titratable Acid? *My assumption is that my lack of
- understanding comes from the German use of sourdough as primarily
- acidification, whereas here we look for a little acidification, a
- good flavor, and good leavening power.*Do German bakers ever make
- wheat breads leavened with higher starter percentages than those
- Brummer cites, for example 20% or 30% starter? *Or do they acidify
- with very ripe starters and leaven with commercial yeast?
-
- I am curious about the flavor/sensory aspects of the FQ: *When a
- bread is fairly sour (SF Sourdough, some rye breads) is the perceived
- sourness mostly lactate, mostly acetate, or due to the pH or TTA of
- the bread? Calvel brings this subject up, but does not resolve it to
- my understanding.
-
- As for your answers to my previous questions, thank you -- I will
- look this material over again, and let you know if I have questions.
- *Do you mind if I put the text of your letter (with attribution) on
- the internet as a posting to the newsgroup Rec.Food.Sourdough? I will
- NOT put your address or email address in the posting, unless you want
- me to. Please let me know, as I think it might become part of the FAQ
- file there (Frequently Asked Questions). I will forward your entire
- letter to a very few people in academia here who have been helping
- me, so you might hear from one of them.
-
- Dan Wing
-
- --
-
-
- 14 Feb 1997 15:50:30 +0100
-
- Dear Dan Wing!
-
- I do not mind if the answer is posted to the rec.food.sourdough: I've
- also been browsing in that newsgroup.
-
- To answer a few of your questions:
-
- I) There is no rye bread without acidification of the dough. Rye
- flour does not contain gluten (or a different type of gluten that
- does not have the gas-retaining properties), so that the structure of
- rye bread relies mainly on gelatinized starch. Rye flour does have a
- higher amylase activity than wheat flour, furthermore, the
- gelatinization temperature is a few degrees lower than that of wheat
- starch. Thus, with the temperature optimum of rye amylase being about
- 50 - 52C (with substantial activity up to temperatures of 70C) and
- starch gelatinization starting at 55C, starch is degraded during the
- baking process UNLESS the amylases are inactivated by lowering the pH
- below 4.5. The situation is exacerbated if there was wet weather
- during the harvest, as germinating rye has higher amylase activities
- and the starch granules are damaged, thus facilitating hydrolysis.
-
- II) "Anstellgut" is more or less the same as the continuously
- propagated wheat starters of the SF sour dough bread, so no harm is
- done if it is translated as "starter sponge" or something like.
- German sourdoughs usually are rye based for two reasons: 1) Due to
- the climatic conditions in Germany, especially in the northern and
- eastern parts that make it difficult to grow wheat, rye flour is just
- as important for bread production as wheat flour. 2) As these is no
- necessity to acidify wheat flour (though it enhances the flavor),
- most bakers do not use sour dough to produce wheat bread. Starter
- sponges are not necessarily propagated separately. If the dough is
- taken care of according to traditional methods, it is re-inoculated
- three times to produce bread dough (reading Bruemmer and Spicher, you
- probably have already encountered the "three stage sour dough
- method." A part of the bread dough is used to prepare the sour dough
- for the next day. This makes 3 - 4 inoculations a day, the ratio of
- sour dough to fresh dough being approximately 1:3. One has to make a
- point of it: there is no typical sourdough without continuous
- propagation! The microflora of these rye starters is actually the
- same as for wheat starter in SF or Italy: Lactobacillus sanfrancisco
- and Candida milleri or Saccharomyces exiguus. The pH of a ripe sour
- dough will be between 3.6 and 4.0 (L. sanfrancisco does not grow
- below pH 3.6). The total titrable acidity (TTA) depends on the flour
- employed: as the lactobacilli acidify to pH 3.6, flours with high
- buffering capacity (amount of acid required to lower the pH), e.g.
- whole flours, have a higher TTA than white flours with a low
- buffering capacity. Furthermore, if "hard" water with high
- concentrations of Me2+ CO3- is used, the TTA will be higher.
-
- 3) Acidification vs. leavening: As mentioned above, rye flour or
- mixtures of rye and wheat flours containing more than 20% rye must be
- acidified in order to get bread. As the propagation of sour dough is
- very time consuming if the full leavening capacity of the organism is
- to be obtained, quite a few processes have been developed in Germany
- that ensure that the dough is acidified (or that the sour dough added
- to the bread dough contains enough acid to bring the pH of the bread
- dough below ca. 4.5), but no leavened by the sour dough microflora.
- Leavening is achieved by bakers yeast. Basically, there are three
- possibilities: 1) Dried sourdough with a high TTA (>20) is added to
- the bread dough, there are no lactobacilli involved in the
- fermentation (sometimes they are present in the dried sour dough
- preparation anyway, as in Germany, something called sour dough must
- contain viable lactic acid bacteria. The dried dough is sold much
- more readily if it can be called sourdough). 2) A sour dough is kept
- at room temperature for up to one week. The TTY of that dough is high
- enough to use it for baking, but as the organisms are rather stressed
- in such an environment, they will not contribute to the leavening of
- the dough. Such doughs do not contain lactobacillus sanfrancisco, but
- other lactobacilli that are more acid tolerant (the ph of such a
- dough reaches 3.4 - 3.6 after one day, and stays there for the four
- or five more days that the dough is kept). 3) One stage or two stage
- processes with starter sponges. One or two stage processes usually do
- not ensure that the lactobacilli in the dough are fully metabolically
- active if the bread dough is prepared, thus, the leavening capacity
- is rather poor, but enough acid has been produced. As far as I know
- (I never made a survey, though), only few bakers make bread with
- traditional processes without bakers yeast added to leaven the dough.
- Acidification of the bread dough with sour dough is rather common,
- and the sensory quality of such bread is quite close to that of bread
- made without bakers yeast. Straight processes with bakers yeast and
- chemical acidification (citric, lactic, and acetic acid, or mixtures
- thereof) are also quite common to produce rye bread.
-
- 4) Lactic acid and acetic acid will change taste and flavor of bread
- beyond the decrease of pH: the taste buds (sour, bitter, sweet,
- salty) are on the tongue, any other aroma is perceived with the nose;
- therefore, the aroma compounds must be volatile. Acetic acid is more
- volatile than lactic acid, thus, it's impact on the flavor is more
- pronounced than that of lactic acid. Spicher says that a ratio of 20
- acetate to 80 lactate is optimal. It must also be taken into account,
- that the lowering of the pH influences the formation of other aroma
- compounds during the baking process. The acetic acid is furthermore
- important as growth of spoilage organisms such as molds or rope
- causing bacilli (Bacillus subtilis) is inhibited by high acetic acid
- concentrations.
-
- I hope that I could answer your questions
-
- With kind regards
-
- Michael Ganzle
-
- ------------------------------
-
- Subject: 28. What is hooch? Refrigerator hooch? What do I do with it?
-
- Hooch and refrigerator hooch are the same thing.
-
- When the starter goes quiet (this tends to happen faster in the
- refrigerator, whence 'refrigerator hooch') the mixture separates. You
- have a layer of flour with miscellaneous yeast and bacteria and a
- layer of water with a touch of alcohol (whence 'hooch') and other
- fermentation byproducts.
-
- You mix the hooch in with the layer of flour when you feed your
- starter otherwise you will change the water:flour ratio of your
- starter.
-
- A better way, in my opinion, to restart an old hooch layered starter
- is to use a tablespoonful of the old starter to get another flour and
- water mixture going as a new starter. You can get a healthier starter
- faster that way.
-
- -Darrell
-
- ------------------------------
-
- Subject: 29. How can I determine the proportion of flour and water to
- use in my starter and dough?
-
- Proportion of water and flour in starter and dough, and why I like
- 100% starters:
-
- A recent poster related difficulty controlling and predicting the
- viscosity of starters. One of the responses referred to the usual
- professional baker's practice of measuring by weight, not volume.
- This is the so-called "baker's percentage" (or "hydration" or
- "absorption ratio"), in which the weight of each of the other
- ingredients is compared to the weight of flour used. Thus equal
- weights of water and flour make a 100% starter, while a typical dough
- made with all-purpose flour is a 60% dough, while one made with all
- "bread" flour is typically about 70%, since the extra protein can
- trap a greater amount of water. Some European bakers use a variation
- of this percentage system, called "dough yield".
-
- Anyway, there is are several advantages to using a 100% starter, with
- equal weights of flour and water. One is because it makes it easy to
- calculate the amount of water and flour (and salt) that must be added
- to the starter to make dough batches of different sizes. For example,
- I like to make large loaves that weigh 1500 grams. Forty percent of
- that is 600 grams of final starter that I will need when I make my
- dough. Forty percent of that amount of starter is 240 grams of
- intermediate starter. One-quarter of that is 60 grams, so that is the
- amount of my "original" starter I begin with per loaf I will make.
-
- Suppose I want to make about 1500g of dough at 65% baker's
- percentage: I divide 1500 by 165 (100% flour, 65% water), then
- multiply the result by 65 (for the total weight of water) and by 100
- (for the total weight of flour) as well as by ) 0.02 (to determine
- the weight of salt needed, which is typically 2%). I am going to need
- 909 grams of flour, and 590 grams of water, as well as 18 grams of
- salt.
-
- Now we see one advantage of using a 100% starter: since I have 600 g
- of "final" starter, I have 300 g of flour and 300 g of water, and I
- can subtract those amounts easily to give me 609g of flour and 290 g
- of additional water, a well as 18 of salt. Adding the starter and
- these amounts of flour, water, and salt will make my dough. These
- easy calculations are essentially the same for any quantity of dough
- you want to end up with on any given day.
-
- The other advantage of a 100% starter is that for MOST starter
- cultures a 100% starter will become ripe in 8 hours or less after
- each substantial refreshment. That is easy to remember and handle--
- thicker starters are often slower, although they last longer in
- storage.
-
- Finally, the acid load of a 100% culture is moderate when it is ripe,
- so it will make a nicely balanced bread (flavor balance) when
- appropriately handled.
-
- -Dan
-
- ------------------------------
-
- Subject: 30. How can I ship my starter to someone else?
-
- Take refreshed starter at peak yeast activity, and add flour to make
- "noodle dough". Roll it flat so that 2/3 oz. or so fills a postal
- envelope. (A postal employee wrote suggesting a cassette mailing box
- available cheaply from Radio Shack -- dg) Wrap it in cling plastic
- and mail it ordinary first class. It should be so dry as to resemble
- slightly damp cardboard.
-
- I assume a white flour starter fed and compounded with same. A week
- in the mail will not bother it. It can be stored in the frig for
- months in this form.
-
- -Dick
-
- ------------------------------
-
- Subject: 31. How do I get that lofty loaf?
-
- Getting the lofty loaf starts way back with kneading and getting the
- correct consistency (percent hydration). This is easier to do when
- you weigh rather than volume-measure ingredients. Next, your
- fermentation stage (after kneading, before dividing and rounding)
- should not be excessively long. Sourdoughs do not have to double in
- bulk in fermentation, as much of their flavor and microbiological
- vigor is carried from the prefermentation stages-- from the sponge or
- leaven you have made from your active starter.
-
- The next most critical determinant of a lofty loaf is shaping. Some
- people shape the finished loaf just after they have divided the
- dough, which works well for plastic doughs, like high percentage rye
- flour doughs. But for elastic and extensible doughs, like well
- hydrated, well kneaded wheat doughs, it is better to divide, round
- the loaves (pre-shape, pre-stretch the dough structure) and let them
- rest about 10 minutes on the bench. Then when you finally shape them
- (means just that, not just making a big lump) you will get the
- necessary gluten tension to provide the lofty loaf you seek.
-
- If you are in doubt, underproofing is better than overproofing, Of
- course perfect proofing is best. But any well shaped, well proofed
- loaf should be able to take slashing by a very sharp knife-- 'been
- doin' it for years.
-
- -Dan
-
- ------------------------------
-
- Subject: 32. What is San Francisco Sourdough?
-
- As I understand it, all stable "sourdough" starters are a symbiotic
- mixture of yeasts and bacteria, that, through their mutual liking of
- the other's by-products, cause the mixture to remain stable over
- time, relatively unaffected by other wild yeasts & bacteria that may,
- by chance, settle into the mix.
-
- In the case of "San Francisco Sourdough" the protagonists have been
- identified as Lactobacillus sanfrancisco (the bacteria) and
- Saccharomyces Exiguus (the yeast).
-
- These two players seem to be common in the air in the San Francisco
- bay area, and hence, starter started there contains them in
- abundance. Their mutual relationship gives bread made therefrom a
- singular tang.
-
- In 1995, I toured the bay area stopping at many bakeries to sample
- their "sourdough". Parisian was the most bland, though most widely
- distributed; Le Bolangerie was the most tangy and "sanfranciscian";
- the Village Baker, in Petaluma, was the most interesting. I did not
- get to Acme in Oakland, which is deemed by some to be, well, the acme.
-
- I, like others on this list, have attempted to duplicate the taste I
- had tasted in SF, here in eastern Mass., with little success. I have
- tried inoculating commercial "San Francisco Sourdough" starter with
- Lactobacillus sanfrancisco, obtained from a baking industry contact,
- to little avail. The resulting loaf _was_ "sanfranciscian" but the
- starter did not retain that quality for the next batch. I believe
- both Lac. SF. and Sacc. Ex. must be in the air & the flour, or the
- symbiosis will not survive in the starter.
-
- Troy Boutte, of this list, wrote in 1995:
-
- "Lactobacillus san francisco, when fermented by itself from a pure
- culture, has an odor of canned corn early in the fermentation. After
- about 17-20 hours of fermentation under good conditions, the pH of
- the ferment will drop to about 3.6 - 3.8. At that time the odor will
- have changed to a very complex and unique odor which of course makes
- it impossible to compare it to anything else.
-
- Most people say it smells like sweaty sneakers or old socks, but not
- in an unpleasant way. ... The odor comes from 40-50 small volatile
- compounds that have been identified in these ferments. Besides
- lactic acid, the most abundant compounds are acetic acid (vinegar),
- ethyl acetate (cross between vinegar and alcohol), and ethanol.
- Other compounds are esters of short chain fatty acids that give goat
- cheese and butter their respective odors and flavors.
-
- I've found that the odor of this ferment bears little relationship
- with the flavor of the bread produced. Baking seems to mellow out
- the flavor, leaving what many people consider to be an excellent
- flavor to the bread."
-
- -George
-
- ------------------------------
-
- Subject: 33. What temperature should my starter be for best results?
-
- Typical sourdough actually may contain three different types of microorganisms.
-
- We all know about yeast and those bacilli that produce lactic acid.
- There may also be different bacilli in your dough, namely ones that
- produce ordinary vinegar or acetic acid.
-
- (There is also the possibility that there are still different
- microorganisms in there, but you usually don't want that to happen.
- Worst example are the bacilli that produce a kind of acid that also
- makes very old butter stink.)
-
- Each microorganism has its own favorite temperature.
-
- The bacilli that produce lactic acid like rather high temperatures of
- 37-40 degrees C or 99-104 degrees F.
-
- The bacilli that produce vinegar are active only if there is yeast
- that has already produced alcohol. (Yeast always does that, it never
- produces gas without producing alcohol, so the word "alcohol" should
- not alarm anyone.) Those bacilli like rather low temperatures, 20-25
- degrees C or 68-77 degrees F.
-
- Personally, I want lactic acid and not vinegar in my sourdough. You
- can tell the two apart by the fact that lactic acid tastes sour, but
- does not smell sour. Also, vinegar escapes as a gas during the baking
- process as well as during storage of the bread, whereas lactic acid
- stays.
-
- Yeast will grow (multiply) fastest at 24-27 degrees C or 75-81
- degrees F. (Yeast also needs oxygen to multiply.) Yeast will produce
- gas fastest at a somewhat higher temperature, namely 30-32 degrees C
- or 86-90 degrees F.
-
- So, my own conclusion from all this is: the temperature which you use
- to maintain the starter will, in the long run, affect the kind of
- microorganisms you have in there.
-
- If you want lots of lactobacilli, use higher temperatures when
- refreshing the starter. If you refresh your starter at comparatively
- low temperatures, you may get a dough that smells sour and contains a
- lot of vinegar, but the resulting bread isn't all that sour.
-
- -Andreas
-
- ------------------------------
-
- Subject: 34. Can I freeze or dry my starter?
-
- With regard to freezing, I have done this for years: I put a cup of
- starter in the freezer and in six months or so thaw and feed it then
- refreeze. It has always worked so I have not understood the
- frequently expressed concern about freezing. I think people should
- always freeze part of their starter for safety's sake. Of course,
- they can always get some more from me by sending me a SASE.
-
- (Ed. note -- be sure your starter can handle freezing like Carl's
- before you rely on this method of preservation.See
- "http://www.nyx.net/~dgreenw/sourdoughfaqs.html#sources" if you would
- like to obtain Carl's starter)
-
- I only dry the starter when I know I am running out, which may be
- every week or two. I prepare a batch of starter for distribution by
- combining one tablespoon of stock starter, 1/3 cup water, and enough
- flour to get waffle batter consistency. I activate this mixture at
- room temperature (about 70 degrees F.) until I can see small bubbles
- in the body of the starter ( not frothing or hooch formation.) (The
- stock starter culture is kept in the refrigerator. It is fed and
- activated every two weeks or so, i.e. whenever I think about it or
- need to use it.)
-
- I pour the activated mixture into three 10-inch diameter plastic
- picnic dishes to a depth of 1/8 to 1/4 inch. It dries for several
- days at room temperature. The dry starter does not stick to the
- dishes. It dries on the top first, but the bottom is then exposed
- with a knife. Otherwise drying would be too slow. One could use
- regular ceramic or metal dishes if you put a layer of plastic
- sheeting over the dishes so the wet starter didn't stick to the dish.
- Waxed paper should work as well. When it is dry and brittle I break
- it up and grind it in a blender. It seems to work OK. I wonder if
- other people always activate their starters before they dry them.
-
- I leave the dried starter in the freezer for several weeks, long
- enough to fill the requests that I get in the mail. Never had a
- report of my starter failing to reactivate. (I test each batch before
- it goes out in the mail by reactivating a portion of it to make sure
- it is OK.) Well, that is just the way I do it. Cooking is not a
- mathematical science. When I learned to cook some seventy years ago
- in a cattle trail chuck wagon and ranch house there were no
- quantities or temperatures in recipes - just did it feel good or look
- right, or taste good, and did the cowhands like it, was all there
- was. This can be checked with many of the recipes from that time. We
- used ones printed in the 1800s.
-
- -Carl
-
- ------------------------------
-
- Subject: 35. What happens if I start my starter with commercial yeast?
-
- Many people believe that a starter started with commercial yeast will
- eventually be "taken over" by wild yeast. This is a good thing, and
- the quality/predictability of the resultant bread should improve as
- this happens, since commercial yeast isn't really designed to be used
- that way. Until that process is completed, the starter is in a state
- of transition toward a desired end-state where wild yeast and
- bacteria maintain a balanced, stable, symbiotic relationship. It
- follows that an evolving starter will produce breads with differing
- characteristics as the nature of the starter changes. Only a stable
- starter will produce consistent results.
-
- It can actually take quite a while for a starter (even one that began
- without commercial yeast) to reach a good balance of microbiological
- life. This is one of the reasons why many bakers use cultures from
- long-established starters (why go through all the time and trouble to
- nurse your starter to a balanced state when there are lots of
- already-balanced starter cultures out there with proven
- characteristics?).
-
- -Sam
-
- There was an experiment done by a Dutch group: baker's yeast didn't
- survive more than two refreshments of a sourdough culture. I think
- that it's the acetate that kills the yeast as it is less acetate
- tolerant than sourdough yeasts.
-
- -Michael
-
- ------------------------------
-
- Subject: 36. What do all these baker's terms like poolish, biga, chef, mean?
-
- Poolish-- Is French for a mixture of flour and water and a little
- bakers yeast. The ratio of flour to water is 50 - 50 by weight.
-
- Biga-- Italian for the same thing except the biga can be like a
- poolish or very firm.
-
- The above are both yeasted.
-
- Chef-- a dough-like starter that is either an unrefreshed levain or a
- piece of dough saved from the previous day's bake.
-
- Levain-- a chef that has been refreshed with flour and water.
-
- Biga Natural-- same as levain, but in Italian.
-
- Mother-- this is a batter like starter of flour and water that is unrefreshed
-
- Sour-- a mother that has been refreshed with flour and water.
-
- Mother = chef - it only depends on the consistency (chef dough-like,
- mother batter-like). Most people here in the US call this just plain
- starter.
-
- Sour = levain - again it depends on the consistency of the starter.
- (Sour batter-like, levain dough-like) - The difference between these
- terms and the ones above is that they represent the term that
- indicates that the starter is activated.
-
- Chef, levain, biga natural, mother, and sour contain only natural
- yeast cultures.
-
- All of the above are often referred to as either starters or sponges.
-
-
- -Matt
-
- --
-
- Chef is a piece of dough held over to start the process of making
- future doughs. It preserves the makeup of the leaven culture used at
- any particular bakery. In the old days, use of la stiff (dough
- consistency) chef was important because there was no refrigeration.
- Stiff consistency = slow fermentation compared to thin consistency.
- Most bakeries now use more liquid leavens, and store them in the
- refrigerator when necessary.
-
- Levain is the French term for a sponge or soft dough that is being
- used to propagate a sourdough culture.
-
- Sponge is a thinner (more watery than dough) dough stage that allows
- for vigorous fermentation. It may incorporate all the water that will
- eventually be in the dough, or some portion in it. When baking with
- commercial yeast, a sponge allows a baker to only use one-quarter the
- amount of yeast, which reduces yeast's off-flavor. When baking with
- "natural ferments"-- sourdough cultures-- the culture is often
- propagated in a series of sponges which are then called levains
- (French), barms, leavens, starters and a few other names. I
- personally have come to use the term "starter leaven" for a new
- leaven culture that is being developed, the term "storage leaven" for
- one that I hold over in the refrigerator, and the term "intermediate
- leaven" for one that I use as a stage of propagation between the
- storage leaven and the dough itself. In France and Germany there are
- specific names for the three levains that make up (with the chef) the
- twenty four hour cycle of the traditional small bakery.
-
- proof -- This term is best used to describe the time of rising of the
- loaves AFTER they have been shaped, although it is also used to
- describe the time of rising before they are shaped. Many professional
- bakers use the term "fermentation stage" for that time after mixing
- and before shaping
-
- Yeasts:commercial -- This refers to yeasts that are propagated in
- nearly pure culture and (these days) usually sold in dried form. In
- the past 10 years manufacturers have moved beyond "natural selection"
- and the refinement of mutations-- they are now using genetic
- engineering. Yeast are available with high resistance to freezing,
- for example. Though most yeast packets contain some bacteria, there
- are not enough to produce the acid and the volatile organic compounds
- that give sourdough bread its flavor. Also, most people use so much
- commercial yeast that the bread tastes more of it than of wheat. The
- amount used can be reduced when bread is made with the sponge process
-
- Yeasts:sourdough -- Bread made with natural leavens: a mixed culture
- of yeast and bacterial strains recovered from environmental surfaces
- (grain, grapes, etc.) and then propagated continuously by bakers.
-
- -Dan
-
- ------------------------------
-
- Subject: 37. What is the relationship between temperature and
- sourdough activity?
-
- Recent information indicates that the time-temperature relationship
- is steeper than was proposed, and not quite so log-linear as had been
- assumed.
-
- Through the range 40 to 75 degrees, rates may double approximately
- for each 7 degrees F., rather than for each 18 degrees F. as I had
- assumed. That is based on information sent to me by Michael Gaenzle,
- who, with colleagues, has studied growth rates of sourdough yeasts
- and bacteria, and on (my) assumption that leavening activity and
- yeast growth are mutually proportional.
-
- Further, Michael Gaenzle (GΣnzle) has shown that sourdough yeast
- growth (for the SF sourdough yeast organism) is severely retarded by
- temperatures much above 85 degrees F. and that culturing above that
- temperature can deplete the yeast, leaving the lactobacillis
- predominant.
-
- Michael's study was published last July in _Applied and Environmental
- Microbiology_, but I have not seen it. I have appended the
- information that I have (an email received last June 28) in case some
- one would like to help me speculate on how a time-temperature table
- might be presented.
-
- There is probably a simple answer about how to adjust "proofing"
- times for various temperatures, but I have come to understand that I
- am not exactly sure what it is just now.
-
- Thanks to Michael for his contributions to sourdough science, and for
- his interest in our discussion group.
-
- - Dick Adams
-
-
- Dear Dick Adams
-
- Please find attached the growth rates of L. sanfranciscensis and C.
- milleri as function of temperature. Growth rate is ln2/generation
- time, i.e. a growth rate of 0.7 is a generation (doubling time) of
- about 1 h.
-
- The generation times measured in laboratory media are different from
- that in rye / wheat / white wheat dough, however, if the generation
- time at 20 C is 1/2 of that at 30 C in my medium, the organism will
- also grow 1/2 as fast at 20 C compared to 30 C in dough (we checked).
- So, it's not the absolute numbers that matter, but the ratio of
- growth rate to growth rate at optimum temperature.
-
-
-
- Temp L. sf I L. sf II Yeast (C. milleri)
- 2 0.019 0.016 0.004
- 4 0.026 0.022 0.008
- 6 0.035 0.031 0.013
- 8 0.047 0.043 0.021
- 10 0.063 0.060 0.033
- 12 0.084 0.08 0.052
- 14 0.11 0.11 0.078
- 16 0.14 0.15 0.011
- 18 0.19 0.20 0.16
- 20 0.24 0.26 0.23
- 22 0.30 0.29 0.30
- 24 0.37 0.37 0.37
- 26 0.45 0.46 0.42
- 28 0.49 0.55 0.42
- 30 0.61 0.64 0.35
- 32 0.66 0.70 0.20
- 34 0.66 0.70 0.05
- 36 0.58 0.54 0.00
- 38 0.39 0.31
- 40 0.1 0.055
- 41 0.00 0.00
-
- The curves were generated by fitting the following curve to experimental data:
-
- growth rate = a (x^b)(e^cx)
- for lactobacilli, x is (41-temperature), all temperatures are in deg.
- centigrade
- for the yeast, x is (36-temperature), all temperatures are in deg. centigrade
-
- A, b and c were calculated as follows for the three organisms:
-
- L. sf I L. sf II Yeast
-
- a 0.1267 0.0682 0.0124
- b 1.5404 1.9782 2.9810
- c -0.1931 -0.2233 -0.3355
-
-
-
- If I didn't make a typing error this equation should generate the
- curve described above. The curve does not give the best approximation
- at temperatures below 10C, though.
-
- Transfer of the curves from our strains to your starter may change
- things a bit, but nevertheless I think that it may serve as guideline
- for many sourdough starters.
-
- Let me know if you think it works (or not).
-
- - Michael
-
- ------------------------------
-
- Subject: 38. Is there a glossary of rec.food.sourdough terms?
-
- ATCC: American Type Culture Collection (www.atcc.org), a source for
- pure strains of micro-organisms, including those that predominate in
- natural leavens.
-
- absorption: The ability of a flour to take up and hold water.
- Generally higher for high-gluten flours and those with relatively
- high damaged-starch levels.
-
- acid: A solution containing free hydrogen ions, or a substance that
- will release them when dissolved in water.
-
- acid pH: Since pH is a measure of the acid/base state of a solution,
- "acid pH" indicates that the solution in question is acid, and a has
- a pH of less than 7 on a scale of 14.
-
- acid tolerance: The ability of a micro-organism to grow in acid conditions.
-
- active starter: A leaven that has recently reached its equilibrium
- yeast and bacterial population. If thick, it will be spongy,
- tenacious, and gassy. If thin, it will be frothy and bubbly.
-
- amylases: Enzymes present in grain but also supplemented by millers,
- capable of breaking damaged starch down to sugars and dextrins. These
- sugars then power fermentation and contribute to carmelization and
- the Maillard reactions (browning of the crust).
-
- Anfrischsauer: The first stage (first expansion) of the traditional
- German baking sequence, made from Anstellgut, water, and flour.
-
- Anstellgut: The inoculant to the first stage in the three-stage
- sequence of expansion of a leaven culture in the traditional German
- bakery. It is a portion of the ripe sourdough from the previous day.
-
- ash content: The mineral content of flour.
-
- autolyse, autolysis: A rest during kneading (5-20 minutes) to allow
- the dough to continue hydrating and the developing gluten to relax
- before kneading is resumed and the gluten is taken to full
- development. Usually done when dough is being machine-mixed.(French,
- English)
-
- bacteria: Single celled organisms with no defined chromosomes (yeast
- don't have defined chromosomes either). Neither plant nor animal.
- Usually smaller than yeasts. Some can ferment, but usually don't make
- CO2 in the same amounts as yeast under typical conditions-- they make
- organic acids instead.
-
- bake: Heat to an internal temperature of at least 195 degrees
- Fahrenheit in a dry environment. For hearth loaves (not in a pan) the
- environment should be humid initially, then dry.
-
- baker's yeast: Strains of brewer's yeast selected and commercially
- produced for raising dough.
-
- baking yeast: Same.
-
- batter: A thin mixture containing flour and water, in the range of
- 100% hydration or higher.
-
- barm: A leaven or starter, sometimes implying one made from brewing
- sediment. (English)
-
- beer yeast: Brewer's yeast selected for making beer.
-
- biga: Originally the same as starter or leaven (natural leaven) but
- now used to refer to a sponge raised with commercial yeast. (Italian)
-
- bottom-fermenting yeast: Brewer's yeast (lager yeast, Saccharomyces
- uvarum) which forms its fermenting mass in the bottom of a vessel of
- liquid.
-
- chef: A piece of a previous batch of dough kept over to inoculate a
- new flour/water mixture, which will then become a leaven, starter,
- sponge (synonyms).
-
- commercial yeast: Factory-produced yeast. The species is the same as
- brewer's yeast, but the characteristics may be very different. This
- term includes baking or baker's yeast.
-
- culture: As a noun, refers to a batch of micro-organisms in a
- nutrient medium, such as a flour/water mixture. Could be "pure" (one
- type of organism) or "mixed" (more than one type of organism).
-
- damaged starch: Starch granules that have been broken in milling and
- are therefore accessible to water and to amylase at temperatures
- below the gelatinization temperature.
-
- detente: French term for the rest period loaves get between the
- division and rounding of the dough at the end of the fermentation
- stage and the shaping of the loaves.
-
- dough: A mixture of flour and water in which the weight of the water
- is in or near the range of 60-75% the weight of the flour.
-
- Dough yield (Teigausbeute): Common expression in bakery books and
- articles translated from German. Same meaning as dough hydration,
- except that the number is stated as 100 parts flour plus X parts
- water equals dough yield. For example, a dough yield of 171 means a
- hydration of 71%.
-
- elasticity: The springiness that allows dough with well developed
- gluten to stretch and return to its previous shape.
-
- environmental surface: In this context, refers to a surface that can
- inoculate a culture, intentionally or unintentionally. It could be
- the surface of a flour particle, your hands, or a bowl. The
- concentration and spectrum of organisms on such surfaces vary widely,
- but is much greater than is found in the atmosphere.
-
- extensibility: The quality (seen in wheat doughs only) of thin-film
- strain hardening, which stabilizes the gas cells of a rising dough
- and prevents the cells from breaking. This life-like quality can be
- felt in the way a good dough complies with handling.
-
- fermentation: Usually means the conversion of sugar to carbon
- dioxide, alcohol, organic acids, and organic volatiles.
-
- fermentation stage: Usually refers to a stage in breadmaking after
- dough is mixed and before loaves are divided and shaped. Sometimes
- referred to as "first proof."
-
- fungi: Plants that lack chlorophyll, ranging from yeasts and molds to
- mushrooms.
-
- gelatinization: Uncurling and hydration of starch chains to form a
- gel. Occurs as a suspension of starch granules is heated.
-
- genetic engineering: The creation of lifeforms containing genetic
- material from other species or genetic material altered in test tubes
- and reimplanted into cells.
-
- gluten: A protein complex prominent in wheat doughs. It is formed by
- the association of two precursor proteins, glutenin and gliadin, and
- by its strength, elasticity, and extensibility determines the
- structure of the dough.
-
- gluten window: "way of testing the level of gluten development in a
- dough. Simply grab a small part of the dough between your fingers and
- very gently and slowly stretch it apart. If the dough holds together
- and stretches into a thin, tranluscent membrane then you've made the
- window and know you've got good strong gluten.": see
- "http://deja.com/getdoc.xp?AN=685915075&fmt=text"
-
- hootch:The liquid layer that can accumulate in the top of a container
- used to store a thin (very liquid) leaven.
-
- humidity: The amount of water vapor (dampness) present in air.
-
- hydration: Several meanings in this context: 1) The weight of water
- in a a leaven or a dough, relative to the weight of flour. Therefore,
- a dough at 70% hydration is 41% water, and a leaven at 100% hydration
- is 50% water. 2) The capacity of a flour to absorb water (usually
- called absorption). 3) The quantity of water in flour (related to
- environmental humidity).
-
- incubate: Encourage growth in a culture by maintaining conditions
- that favor the growth of the organisms in the culture.
-
- inoculate: To introduce a micro-organism to an appropriate medium for
- its growth.
-
- knead: To continue mixing a dough beyond the point when the
- ingredients are uniformly distributed. This first causes abrasion of
- flour particles, then suspension of starch granules and hydration and
- linking of flour proteins.
-
- lactobacilli: Rod-shaped bacteria that typically produce lactic acid
- as the major end-product of their fermentation.
-
- leaven: That which raises bread by producing carbon dioxide. In this
- context, it is a batter, sponge, or dough that contains a mixed
- culture of yeast and bacteria that has been continuously maintained
- by a a series of inoculations and incubations.
-
- levain: French for leaven.
-
- Levain de tout point: The final leaven in the sequence of leaven
- expansions in traditional French baking. Used to make up the dough.
-
- liquid medium or media: A mixture of nutrients and water, in which
- organisms may be propagated.
-
- Malt: Dried and ground sprouted barley, high in amylase, that is
- added to flour to guarantee that plenty of sugar is available to
- fermentation. If excessive, leads to excessive dextrin formation,
- slack doughs, and gummy crumb and crust.
-
- mix: Used by professional bakers to include both mixing until the
- dough mixture is blended AND for what others call kneading.
-
- mutation: A change in the genetic makeup of a strain of organisms
- that may lead to a change in structure or function.
-
- mycologist: A scientist who studies fungi.
-
- overproof: To allow the last stage of rising to last too long for the
- temperature and fermentation activity of the dough. Makes slack
- loaves, often with poor volume, shape, and crumb texture.
-
- pH: A measure of the hydrogen ion concentration (on a logarithmic
- scale) in a solution, from 0 to 14. Values less than 7 are acid,
- while values over 7 are basic.
-
- pointage: The fist rising after mixing (usually called the
- fermentation stage). (French)
-
- proof: Usually means the final stage of rising, after the loaves have
- been shaped. Sometimes used ("first proof") to refer to the rise
- after kneading and before loaves are shaped (fermentation stage), or
- to a test done to see whether commercial yeast is still viable.
-
- r.f.s.: Rec.Food.Sourdough-- Usenet group about natural leaven baking.
-
- refreshment: Adding water and flour to a leaven to increase its
- volume and feed its culture.
-
- retarding: "Retarding simply means putting your loaves into cold
- storage, the refrigerator, for awhile. This allows you to bake at a
- later date, early in the morning if you wish, and it affords the
- microorganisms in your dough a long, slow time to work, developing a
- tastier and more sour bread." See
- "http://deja.com/getdoc.xp?AN=684633117&fmt=text"
-
- Sauerteig: Sourdough. (German)
-
- selective breeding: Traditional type of genetic manipulation by
- selection and propagation of organisms with desired characteristics.
-
- sour: In this context, means a leaven, dough, or bread high in
- lactate, acetic, and other organic acids.
-
- sourdough: A bread, dough, or leaven that contains a mixed culture of
- yeast and bacteria that have given it an acid pH.
-
- sponge: A thick batter or thin dough with hydration somewhere above
- 75% and a little less than 100%.
-
- sponge leaven: A sponge that has been inoculated with a leaven
- culture, then incubated until it is ripe.
-
- stable culture: One that has been propagated through many generations
- and is not changing in its microbiological composition.
-
- starter: Something that can be used to inoculate a sourdough culture.
- Essentially the same thing as a leaven.
-
- starter sponge: A ripe leaven of sponge consistency.
-
- starter leaven: Could be used to describe a new sourdough culture,
- being propagated from an infusion of flour (or fruit) in water.
-
- storage leaven: One that is used to preserve the culture from one
- baking session to the next. Usually kept in a refrigerator.
-
- supernatant: The same as hooch the liquid that rises to the top of a
- flour/water suspension that has settled.
-
- symbiotic association: In this context, two micro-organisms that have
- complementary metabolic needs and products, and resistance to toxic
- products that each other produce. This makes their mixed culture more
- robust and less susceptible to disruption by a third organism that
- may be introduced.
-
- temperature: Same as the conventional meaning-- the temperature of a
- leaven or a dough can be influenced by the environmental temperature,
- by the process of fermentation, and by mechanical work such as
- kneading. Because fermentation is more vigorous at higher
- temperatures and because the relative production of fermentation
- changes with temperature, control or accommodation to temperature is
- important in consistent baking.
-
- time: The conventional meaning-- but it will need to be adjusted if
- temperature is not controlled.
-
- titratable acid: The amount of acid present, regardless of the pH of
- the solution. The TA may be higher than expected if the buffering
- effect of ingredients (flour with a high ash/mineral content) is high.
-
- top-fermenting yeast: Brewer's yeast (ale yeast, S. cerevisiae) which
- forms its initial fermenting mass in the top of a vessel of liquid.
- The progenitor of commercial bread yeasts.
-
- Vollsauer: The third and last stage of leaven expansion in German
- baking. Some of this is saved to become Anstellgut, and the rest is
- used to prepare the dough.
-
- Wild yeasts: Used casually to refer to the yeasts in sourdough
- leavens and doughs. They are not "wild" anymore when they are part of
- a stable culture, but the term is used to differentiate them from
- commercial yeasts.
-
- yeast: Single-celled fungi that ferment sugars and produce CO2,
- alcohol, and other organic products. There are many species, usually
- differentiated by their metabolic/biochemical characteristics.
-
- -Dan
-
- ------------------------------
-
- Subject: 39. What factors affect microbial growth in sourdough?
-
- We've been doing quite some work to figure out which factors affect
- microbial growth in sourdough. I've done some work in vitro (which is
- about to be published: Ganzle et al., Modeling of growth of
- Lactobacillus sanfranciscensis and Candida milleri in response to
- process parameters of the sourdough fermentation, Applied and
- Environmental Microbiology, July 1998); and a colleague of mine,
- Markus Brandt, has tried to figure out how my "model predictions"
- work out during the actual dough fermentation. Taken together, one
- can state the following:
- For sourdough lactobacilli:
-
- A) 32░C - 33░C (89.6F - 91.4F) -- optimum growth
-
- B) 37░C & 20░C (98.6F & 68F) -- double generation time
-
- C) 39░C & 15░C (102.2F & 59F) -- fourfold generation time
-
- D) 41░C & 4░C (105.8F & 39.2F) -- no growth
-
- For the yeasts, the figures are as follows:
-
- A) 28░C (82.4F) -- optimum growth
-
- B) 32░C & 20░C (89.6F & 68F) -- double generation time
-
- C) 34░C & 14░C (93.2F & 57.2F) -- fourfold generation time
-
- D) 35░C & 8░C (95F & 46.4F) -- no growth.
-
- So: if several refreshments are done above 32 C, the yeasts will drop
- out eventually. The optimum pH for lactobacilli is 5.0 - 5.5 (which
- is the initial pH of a sourdough with 5 - 20% inoculum), the minimum
- pH for growth is 3.8 (they usually produce acid until pH 3.6 is
- reached).
-
- Lactic or acetic concentrations don't affect growth of lactobacilli
- very much: this is the reason why the buffering capacity of the flour
- is so important for the organism (a high buffering capacity in high
- ash flours means that the lactobacilli produce much acid until the
- critical pH is reached). It also means, that in doughs that are
- continuously operated with a high inoculum (more than about 30%),
- you'll find more yeasts and fewer lactobacilli. Eventually, the
- lactobacilli flora may change, with more acid tolerant lactobacilli
- (e.g. L. pontis) prevailing. Such a sourdough is found in the Vollmar
- and Meuser continuous sourdough fermentation machines (there are 6
- operating in Germany, and a diploma candidate in our department
- characterized the microflora of several of these: as the machine is
- operated with a 50% inoculum, the pH is never above 4.1 - 4.3, and no
- L. sanfranciscensis is found in those doughs).
-
- Yeasts are different: they don't mind the pH at all, but are strongly
- inhibited by acetic acid, and to a much lesser extent by lactic acid.
- Increasing salt concentrations inhibit growth of lactobacilli, but
- yeasts tolerate more salt. No salt is added to the sourdough until
- the final bread dough, but the dough yield affects the salt
- concentration: with a low dough yield (little water), the salt (ash)
- is dissolved in a smaller water volume, and the salt concentration
- goes up: resulting in a slower fermentation.
-
- So much for the "in vitro" theory. Surprisingly, Markus has found
- most of the predictions to come true when he was looking at the cell
- counts at different temperature, size of inoculum, salt
- concentration, and pH in rye dough. The variation of the inoculum
- size was interesting: If he reduced the inoculum size by 2, he had to
- wait almost exactly one generation time (one doubling time of the
- lactobacilli) longer until the dough has reached the same cell
- counts, pH, titrable acidity, and so on as the dough with the higher
- inoculum. This was true for inoculum sizes between 1% and 20%: at 50%
- inoculum, the pH is so low that the lactobacilli don't really grow
- well, and at an inoculum size of 0.1%, the pH and/or the oxygen
- pressure in the dough are so high that the cells have a lag-time (see
- above) of an hour. Thus, a scanty inoculum means one generation time
- longer fermentation.
-
- The generation time of L. sanfranciscensis in rye dough at 28 C is a
- little less than an hour (figures may vary with different strains in
- different flours, but it's not much more or less than that), so if
- the inoculation size is reduced from 20 to 2.5%, it'll take about
- three hours more until the dough is ripe.
-
- The question is, whether these findings are true for all flours and
- for all organisms. The strain isolated by Kline and Sugihara does not
- differ very much from the two strains I've been looking at. All the
- literature available tells me that - as long as we're looking at
- sourdoughs with a tradition of continuous propagation - the system
- behaves the same way. Differences may be between rye flour and white
- wheat flour: in white wheat flour, the enzyme activities are so low
- that the organisms may run out of food before the critical pH
- (lactobacilli) or the critical acetic acid concentration (yeasts) is
- reached.
-
- -Michael
-
- ------------------------------
-
- Subject: 40. Should I use an established starter or make my own starter?
-
- Well, it all depends on whether you are interested in sourdough
- baking because you want to make good bread or whether you are also
- interested in the challenge of creating your own sourdough starter.
- Even with a predictable starter culture, sourdough baking can be
- occasionally tricky. For someone who has never baked sourdough bread
- before and may be experiencing trouble, beginning with a predictable
- starter eliminates one possible source of trouble.
-
- How do "established" starters get that way? They are propagated for
- years and years, generations and generations. Also, "established"
- starters are the end result of selective disposal. For every
- 100-year-old starter there were countless starters that thrown away
- because their properties were simply not special enough to merit
- saving. People did, in fact, give up on all those other starters.
- Further, it is a relatively well-accepted fact that certain special
- properties in sourdough cultures don't come into being until a
- certain amount of time has passed. For example, one can reasonably
- expect that the symbiotic relationship between microorganisms that
- have coexisted in a starter for several decades will be much stronger
- than what is found in a months-old starter culture. This is one
- reason why these old, established sourdough cultures are such
- consistent performers and are often quite resistant to
- change/invasion by other sourdough microorganisms.
-
- So the question becomes whether you want to learn how to surf or
- whether you want to learn how to make your own surfboard. Most
- people would agree that it makes a lot more sense to learn how to
- surf first, rather than doing both at the same time. Billyfish
- illustrates this well in his posting. Here is a guy who has been
- struggling for a long time with various starter recipes. He finally
- gets some satisfaction, finally feels like he can experiment with his
- technique and concentrate on making the kind of bread he wants
- *after* acquiring a proven starter from SDI. I think he sums it up
- perfectly by saying "I now have a starter that is sufficiently
- predictable to allow experiments to proceed."
-
- *This* is why so many of us recommend starting with an established
- sourdough culture.
-
- -Sam
-
- ------------------------------
-
- Subject: 41. Can I use metal utensils with sourdough?
-
- A sourdough starter is acidic. Prolonged contact of your acidic
- starter with metal will discolor your metal utensil and dissolve tiny
- amount of the metal into the starter if you leave it for, say, weeks.
- So it is not a good idea to keep a sourdough starter in a metal
- container unless you want discolored, or given years of contact,
- damaged utensils. Your starter, or you, may not like the small amount
- of metal that is dissolved into the starter either.
-
- So use a starter container made of a material that is not affected by
- acid. My personal preference are standard wide mouth glass quart
- canning jars, also known in North America as Mason jars. Mason jars
- are readily available and the wide mouth makes them easy to clean.
- Glass is highly acid resistant, very easy to clean and sterilize,
- which makes it a preferred material for starter storage.
-
- In the short time of mixing and rising of sourdough bread, the effect
- of a slightly acidic mix is not noticeable on metal utensils, such as
- spoons and bowls. So there is simply no problem in using metal
- utensils, especially stainless steel utensils, to make sourdough
- bread.
-
- -Darrell
-
- ------------------------------
-
- 42. What is a good source for technical information on sourdough starters?
-
- Here are links to several useful and interesting technical sources :
-
- The first four URLs are noted as "Long Technical Posts 1-4" by Dan
- Wing and are correspondence from Michael Gaenzle to Dan Wing. Michael
- is commenting on the first proof of Dan's book, The Bread Builders -
- Hearth Loaves and Masonry Ovens' by Dan Wing and Alan Scott, an
- excellent book by the way.See
- http://www.nyx.net/~dgreenw/whataboutdanwingsnewbookth.html for my
- review.
-
- <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=wagons-0301041020310001%40port-1-26.wellsriver.connriver.net">Long
- Technical Post 1 by Dan Wing</a>
-
- <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=wagons-0301041021200001%40port-1-26.wellsriver.connriver.net">Long
- Technical Post 2 by Dan Wing</a>
-
- <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=wagons-0301041021590001%40port-1-26.wellsriver.connriver.net">Long
- Technical Post 3 by Dan Wing</a>
-
- <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=wagons-0301041022540001%40port-1-26.wellsriver.connriver.net">Long
- Technical Post 4 by Dan Wing</a>
-
- More <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=Darrell_Greenwood-ya02408000R1502971627290001%40news.mindlink.net">technical
- correspondence</a> by Dan Wing
-
- Sam Kinsey with some <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=6igrn7%24b28%241%40nnrp1.dejanews.com">quotes
- and comments</a> on yeast growth
-
- Sam Kinsey with <a
- href="http://groups.google.com/groups?q=a&ic=1&selm=6idcrr%24evv%241%40nnrp1.dejanews.com">some
- quotes</a> from the American Association of Cereal Chemists site
-
- Search over 38 years of Cereal Chemistry Abstracts at
- http://www.scisoc.org/aacc/searchcs/
-
- -Sam/Darrell
-
- ------------------------------
-
- 43. How do I convert yeast bread recipes to SD recipes?
-
- When converting recipes to sourdough I always make sure that I build
- my "sponge" with the smallest possible inoculum (usually a
- tablespoon). This way, you know exactly how much water and flour you
- are using (it's never easy to tell how much of what you're actually
- getting when you take starter directly from the jar unless you weigh
- the ingredients and maintain a 1:1 starter).
-
- In general, I think it is a good idea to build a nice active sponge
- that contains somewhere between 5% and 20% of the total flour in the
- recipe. You will want to experiment with the percentage of sponge to
- see which results you like.
-
- Here is a hypothetical example of what I mean: Let's say that the
- original recipe calls for 1000g of flour, 600g water, 20g salt and
- 20g yeast... If I wanted a 20% inoculum, I would make a sponge using
- 200g (20% of 1000g) flour, 300g water and one tablespoon of starter.
- Once the sponge was nice and active, I'd mix the sponge with 800g
- flour, 300g water and 20g salt. By using this method, I know that my
- dough has exactly the same amount of flour/water as the original
- recipe. At this point, all I have to do is mix the ingredients
- according to the recipe, proof and bake. The "new" version of the
- recipe should turn out very similar to the original, since the only
- substantial difference is in method of leavening.
-
- Two things to keep in mind: 1. One cannot generally do multiple
- risings with sourdough as with yeast doughs. The rising schedules
- called for in the original recipe should be modified with this in
- mind. 2. The defining characteristics of certain bread styles seem
- fairly dependent on fast-acting yeast. For example, a sourdough
- baguette or a sourdough ciabatta will not be all that similar to the
- original.
-
- -Sam
-
- ------------------------------
-
- 44. What is meant by a "fully activated" starter?
-
- You want to mix your dough when your starter (or sponge) is fully activated.
-
- I'd suggest that you take a few days and get to know your starter and
- its cycles. You might want to find some sort of container that you
- can mark - either with a pen or a piece of tape or you can tape a
- strip of paper vertically on the container and use that. Glass
- canning jars work well and you can easily see into them, or anything
- else that's straight-sided (easier to judge volume increases than
- flared-sided containers, like most bowls).
-
- Take a little starter and feed it, in whatever ratio of starter to
- new food you intend to use regularly (I tend to use 1 oz starter and
- add 6 oz combined flour and water (or even 4 oz combined water and
- flour if I'm going to be doing a number of feeding cycle), but use
- what you are comfortable with). Feed the starter and then just watch
- it. Every hour mark the container as to the level of the starter.
- Check it after 12 hours. If it's started to separate and form hooch,
- feed it again. If not, leave it for another 12 hours.
-
- Next time you feed it, discard most of the starter (or use it bake
- with or to build a sponge) and add your water and flour (I do the
- same as I described above, discard down to 1 oz, add water & flour. I
- add equal amounts of water and flour by weight, not by volume (I just
- find it easier, and I always know how much of an amount of starter is
- water and how much is flour). This gives me a pretty thick starter,
- which is my preference).
-
- The cycle of a starter after being fed and left to sit out at room temp is:
- - for a while, it looks like nothing is happening - then you will
- notice small bubbles beginning to form - the volume will start to
- increase
- - this will go on for some time, with more and more bubbling and
- increasing in volume
- - eventually, the starter will be fully activated. At this point, it
- should be full of bubbles which are well-integrated throughout the
- starter (not just on top) and it may have a layer of foam or froth on
- the very top. If you starter is a very thin consistency, you may
- instead have a couple of inches of foam on the top and not so much
- bubbling within the starter. If your starter is thick enough, it will
- have at least doubled in volume. This is called the starter's "Peak".
- - it will stay at this level for a some amount of time. - eventually
- the starter will sort of fall back into itself, the volume will drop
- and the bubbling will decrease. - at some point later, the starter
- will have evened out, no bubbling will be present, and the starter
- will be a calm, thin batter sitting in the bottom of your container.
- - eventually, it will begin to separate and form hooch.
-
- It's my understanding that peak yeast activity occurs while the
- starter is plateauing or just starting to fall back into itself, and
- that this is the optimum time to use the starter.
-
- How long a cycle takes depends on several things: - the starter
- itself, and the mix of organisms in the starter - the consistency of
- the starter (thick ones take longer than thin ones) - the temperature
- at which the starter is sitting (as well as the temp the starter was
- when you began and the temp of the water & flour used) - possibly
- your altitude (slower at high altitudes) But as a general rule, a
- cycle takes 8 - 12 hours but some starters, like SDI's Russian
- Starter, are much faster than that.
-
- So, my suggestion is that you put your starter through some feeding
- cycles and pay attention to what it does. Not that you need to watch
- it every minute, but check on it every hour or so and mark it's
- level, or keep notes of the time and what the starter looks like.
- Then you can play around with activating it at different temperatures
- or different consistencies and see how that change affects it.
-
- If you do this, you'll really get to know your starter. You'll know
- what it looks like when it's fully activated (at it's peak), or where
- it is in its cycle, and how long everything takes. This will give you
- a much better handle on baking with the starter.
-
- One thing you'll notice as you read some of the sourdough literature
- is that there are discrepencies and variances with just about every
- aspect of starter maintenance and baking procedures. Keep in mind
- that there is no one, true way when it comes to sourdough. The stuff
- is so flexible, adaptable and variable, that all kinds of procedures
- and methods work with it. The trick is to experiment and find out
- what works for you, with your starter, in your environment. It takes
- a bit of experimentation to find that for yourself, though. Keep
- talkin' and keep readin', you'll come across lots of people's ideas
- that you can try out.
-
- -Beth
-
- ------------------------------
-
- 45. What about Dan Wing's new book "The Bread Builders"?
-
- I had a very interesting book pop through the mail slot recently,
- 'The Bread Builders - Hearth Loaves and Masonry Ovens' by Dan Wing
- and Alan Scott.
-
- When Dan wrote me for my address so he could send me a review copy he
- noted in his enthusiasm for his newly minted book "It's a really good
- book." After receiving it yesterday I noted in my enthusiasm for his
- newly minted book, "It's a really good book" and it is :-).
-
- You get for your $35 the best book I have read on "natural leavens"
- or sourdough. It has no recipes but sets out to teach you the basics
- underlying baking bread with no commercial yeast... and succeeds very
- well. The book is 254 pages, paperback, indexed, and well illustrated
- with color and b&w photographs, graphs, line drawings and a glossary.
-
- Starting out with interesting introductions by Alan Scott and Dan
- Wing, the book's chapters wind their way through Naturally Fermented
- Hearth Bread, Bread Grains and Flours, Leavens and Doughs, Dough
- Development and Baking, Ovens and Bread.
-
- Interspersed in the chapters are 'visits' where a separate article
- describes a visit to an interesting bakery or baking related location
- ranging from Vermont to California. The book's clear and easily
- readable style is assisted with sidebars and notes clarifying various
- points. I do like the notes in the margins as this book does rather
- than at the bottom of the page.
-
- But wait, that is only half the book. You get thrown in for free
- another book, on how to design, build and operate a masonry oven. Its
- chapters range through Masonry Ovens of Europe and America, Preparing
- to Build a Masonry Oven, Masonry Materials, Tools and Methods, Oven
- Construction, Oven Management and A Day in the Life at the Bay
- Village Bakery. If you are not up to rushing out to build a masonry
- oven right away, 3 methods are given to approach the results in a
- masonry oven, cloche, baking stone, and you'll have to read the book
- to see what I am going to be doing with a metal pot, cookie sheet and
- pie plate.
-
- All in all I believe this book is a good read for aficionados of
- sourdough, and they would find it a good reference work for inclusion
- in their library. As a book for someone switching from baking yeast
- bread to "natural leaven" bread they would probably regard ownership
- of this book as priceless gift. For someone starting out in bread
- baking it would allow them to get a really good understanding without
- all the "old wive's tales" that unfortunately dog some sourdough
- advice. I know it will find a treasured place in my library and be
- well thumbed through as it assists me in achieving the perfect loaf.
-
- Thanks Dan.
-
- -- Darrell
-
- p.s. The publishers are Chelsea Green Publishing, 1 800 639 4099,
- http://www.chelseagreen.com, ISBN number is 1-890132-05-5, $35 also
- at Amazon ~$28 http://www.amazon.com/exec/obidos/ASIN/1890132055/
-
- ------------------------------
-
- 46. What's all this about natural leaven and L. sanfranciscensis?
-
- Dan wrote: "I chose to write "natural leaven" because it is less
- awkward than 'mixed ferment cultured from the environment and
- sustained with repeated inoculation.'" -- Dan
-
- Michael replied: "Sustained with repeated inoculation" is better than
- anything I was writing to say the same thing. "Cultured from the
- environment" is certainly true - L. sanfranciscensis and the yeasts
- must come from somewhere - but somewhat misleading, as these
- organisms most probably do not originate from the grain, or the flour
- (Marco Gobbetti, whom I mentioned earlier has been looking for L.
- sanfranciscensis on all kinds of Italian wheat flours, and he has not
- found any.
-
- In every Italian dough "sustained with repeated inoculation" you'll
- find L. sanfranciscensis to be the dominating species, though. No
- other scientist has been able to isolate L. sanfranciscensis from any
- other source than sourdough, but all sourdough "sustained etc."
- contain this organism as the dominating flora.
-
- A possible source may be the humans: there are all kinds of
- lactobacilli thriving in the mouth, the intestines, etc. Hammes met a
- South African Microbiologist who claimed to have isolated L.
- sanfranciscensis from the teeth of pre-school children. The data is
- not published, so I don't know what science is behind this claim.
- But, whereever L. sanfranciscensis comes from, it most probably does
- not come from the flour.
-
- ...
-
- I think it does not matter when the first batch of a new sourdough
- stinks - the good bacilli will come out eventually, and they may come
- faster if fermentation is done around 25 - 30░C (as mentionned
- earlier, the temperature optimum of L. sanfranciscensis is 32 -
- 33░C). There has been nice work done in Rudi Vogels lab on the
- microflora of a freshly started sourdough: first, there are
- Enterobacteria (Escherichia coli, Salmonella, Enterobacter), highly
- undesirable organism that stink terribly, then there are
- homofermentative lactobacilli (good, but no gas production), then
- acid-tolerant, heterofermentative
- lactobacilli. I think, this took about 48 hours at 30░C. The stink at
- the beginning does not matter as the organisms will be diluted out or
- die eventually.
-
- No L. sanfranciscensis, though, these will occur only after repeated
- refreshments. Peter Stolz of the B÷cker company told me that it takes
- about two weeks of repeated inoculations to get a good
- "sanfranciscensis" sourdough. I don't know whether or not this
- process was sped up in his case as, due to his workplace, his skin is
- all covered with L. sanfranciscensis.
-
- -- Michael
-
- --------------------------
-
- 47. How does one measure the ph of sourdough, and what is the effect
- of different ph's?
-
- For sponges and doughs:
-
- *Weigh 15 g of sponge or dough and place it in a polyethylene container.
-
- *Add 100 ml of distilled water to this sample.
-
- *Seal the container and shake until the sponge or dough sample has
- completely dispersed.
-
- *Place electrode(s) in the mixture and read the pH value.
-
- *After the pH value has been obtained and recorded, slowly add 0.1N
- NaOH from the buret and stir constantly until a constant pH of 6.6
- is obtained. Read the buret and record the number of ml of NaOH used
- (that is the TTA or Total Titritable Acidity). Take care not to add
- the NaOH too rapidly to avoid going beyond pH 6.6.
-
- For bread:
-
- *Weigh 15g of bread, excluding the crust, into a clean dry container.
-
- *Add 100 ml of distilled water, seal the container and shake until
- bread disperses into a semi-liquid mixture.
-
- *Determine and record pH and TTA as described for brew.
-
- Some useful information for all you "sourheads" out there:
-
- Overmatured sours, i.e., replenished sours matured over 8 hours at
- 77F, may build up excessive acidity and the lactic acid bacteria will
- start to inhibit the propagation of yeast cells, i.e., slowing the
- leavening activity in the sourdough.
-
- A good and fully matured functional sour has a pH of 3.9-4.1 and a
- total titratable acidity (TTA) of 13-15 ml. Sours that develop
- acidity equal to a TTA of 18-22 ml or higher with a pH of 3.8 or
- lower will gradually lose their ability to produce enough carbon
- dioxide to leaven bread loaves. Having a high acid content also makes
- doughs softer and makes their cell structure break down during
- rounding and moulding. This tends to result in an irregular cell
- structure with thicker cell walls in the bread crumb and a tougher
- bite. This effect is intensified in doughs with a relatively high
- water absorption (over 62% of flour weight). However (for all you
- artisans out there), bread of this type is acceptable as "signature"
- bread served in restaurants or for personal use or for artisan type
- bakeries.
-
- Other useful information concerning industry "normal" pH and TTA in
- breads and their process:
-
-
-
- Sourdough starter 3.9-4.1 pH 14-16 TTA
-
- Mixed dough 4.6-4.8 pH 5-7 TTA
-
- Proofed dough 4.2-4.4 pH 9-13 TTA
-
- Crumb 4.3-4.5 pH 6-7 TTA
-
-
-
- *TTA values are expressed as ml of 0.1 N NaOH per 20g sample
- (sourdough starter containing 47.6% flour) titrated to pH 6.6
-
- **This is according to the American Institute of Baking, and not the
- FDA, so I imagine that would explain some differences in "normal" pH
- readings.
-
- -- Dave
-
- -----------------------
-
- 48. Should I use more than one rise for my bread?
-
- Some will tell you "one rise is best". Others feel that you can get
- a finer crumb with multiple risings. Some feel that you can't get
- good rise on second, or third, risings. Others feel one rise is not
- enough, that good bread requires more than one rising.
-
- Some people report good rises on second and third risings, others say
- the second stays as flat as a pancake.
-
- Looking at the posts, I think there are a number of factors at work.
- Here are some of them:
-
- 1. The starter is an obvious difference, as some are more lively than others.
-
- 2. The baker's technique. A bit of gentle kneading is required
- between rises or the culture (or even baker's yeast) can't get to the
- nutrients in the dough.
-
- 3. Altitude. If someone is at a higher altitude, it's easier to get
- second, third, fourth, or more risings than at lower altitudes.
- Let's think in terms of higher altitudes being above a mile or so
- above sea level.
-
- 4. Flour - some flours have more nutrients than others, so some will
- keep feeding the culture longer, and let the bread rise better. Some
- have more, or less, gluten which also impacts rising. Some cultures
- will degrade gluten if they are allowed to work too long, which can
- tie into number 1, above.
-
- 5. The recipe. If the recipe provides other nutrients for the
- culture, or has ingredients that interfere with the culture's
- working, that can be an issue also.
-
- 6. Expectations. What is "a well risen loaf"? Some people look for
- big holes in their bread, others for small. Some want a light fluffy
- loaf, others want a dense loaf. All call their loaves "well risen".
-
- On the pan front, a pan helps a loaf hold it's shape. To be a bit
- indelicate, think of a woman past her youth with, and without, a bra.
- A pan helps dough hold it's shape on five sides. A free form loaf
- has support only on the bottom.... or no support at all. So the free
- form loaf has to have good structural integrity to maintain it's
- shape. With higher hydration doughs, this becomes more of a
- challenge to the baker.
-
- -- Mike
-
- In my opinion, people new to sourdough bread baking should remain
- with one rise until they are satisfied with their bread density.
- People converting their bread baking from baker's yeast should also
- use one rise initially, as they will not be familiar with the
- enzymatic degradation of the dough one gets with sourdough, nor be
- familiar with the much slower rise times of sourdough bread.
-
- -- Darrell
-
- -----------------------
-
- 49. What is Salt Rising Bread?
-
- Salt rising bread (SRB) is leavened by the bacterium Clostridium
- perfringens rather than a yeast as used in sourdough.
-
- I have described two reliable recipes in an article presented in
- Petits Propos Culinaires No.70 (PPC is published in England and
- focuses on history of cuisines and foodstuffs).
-
- I have improved one recipe to speed the process to deliver two loaves
- of SRB by mid-day after setting a pre-starter the evening before. If
- you adhere to the following, you can do the same.
-
- In the early evening, set the pre-starter -
- Two cups of scalded milk, immediately after removing from heat,
- Stir in two cups of corn meal, and
- Three tablespoons of wheat gluten.
-
- Cover the container loosely with plastic wrap or similar and place it
- in a space that can maintain a temperature between 95 and 105 degrees
- Fahrenheit. The temperature is important - ten degrees less and
- action slows dramatically.
-
- First thing in the morning, make up the starter -
- To the pre-starter, stir in,
- One cup hot tap water (~125F),
- One-and-a-half cup flour,
- One-half teaspoon bicarbonate of soda.
-
- Loosely cover the container and return it to the heat box. In about
- two hours the slurry will be covered with bubbles or foam and will
- have increased volume by 10 or 15 percent. When it reaches this
- state;
-
- Make up the dough, add to the starter -
- One tablespoon sugar,
- One teaspoon salt,
- Three tablespoons shortening (oil or solid), and
- Flour enough to make a stiff dough (heat the flour till warm to the touch).
-
- Divide the dough in two, form loaves, and place in greased pans. Oil
- the surface, if you please. Put the pans into the heat box for about
- two hours when the dough will have risen to the pan edge. Bake in
- 350F oven for an hour or until nicely browned.
-
- Any kind of corn meal will be satisfactory (organic, inorganic,
- white, yellow, stoneground, ripped to shreds by steel,
- what-have-you). Every grain I have tried has produced a satisfactory
- starter. Oak bark will inspire a starter in my experience.
-
- The secret to a fast and reliable process is the heat and gluten. Of
- the two, the heat is probably most important.
-
- -- Reinald
-
- In subsequent correspondence Reinald comments:
-
- I have made SRB for about 40 years with the early years as confused
- as many people are today. In 1981 I discovered that a fraction of
- Campden tablet did a much better job of killing yeast than does salt.
- A couple of years ago, after e-mail exchanges with Susan Ray Brown, I
- repeated the 1981 experiments with different grains (oat meal, corn
- grits, barley, etc.) and went on to try just about everything I could
- find at the local natural foods store (wheat flakes, wheat bran, rye
- flakes, oat bran, steel cut oats, etc.) Practical SRB starters will
- develop from all of them.
-
- Venturing further afield, I tried slivers of bark from white oak
- (Quercus alba) and black locust (Robinia pseudoacaca) as initiators
- on wheat flour with Campden; again to obtain useful starters. Next
- was cheddar cheese and blue cheese and, finally, flour alone. All
- worked.
-
- A professional food chemistry laboratory ran DNA analyses on the
- Clostridium strains in flour, corn meal, and cheddar cheese mediated
- starters. The cheese Clostridium was perfringens Type A with an
- exact match to their reference pattern; flour and corn had patterns
- quite similar to the Type A, but not identical.
-
- I also monitored pH of various starters as they developed.
- Perfringens thrives in a basic solution even as it is producing acid
- which eventually arrests activity. Bicarbonate of soda buffers the
- acid to facilitate perfringens action; it is not part of the
- leavening process.
-
- -- Reinald
-
- -----------------------
-
- Subject: 99. Authors
-
- Dick -Dick Adams -- dick.adams (at) bigfoot.com
-
- David -David Auerbach -- auerbach (at) unity.ncsu.edu
-
- Mark -Mark Avery -- http://www.sourdoughhome.com
-
- Beth -Beth -- housewolf (at) hotmail.com
-
- Troy -Troy Boutte -- tboutte (at) delphi.com
-
- Michael -Michael Ganzle -- michael.gaenzle (at) blm.tu-muenchen.de
-
- Carl -Carl Griffith -- (deceased)
-
- Dave -Dave J. -- thebakery (at) worldnet.att.net
-
- George -George Kavanagh -- GK05 (at) earthlink.net
-
- Sam -Sam Kinsey -- slkinsey (at) aol.com
-
- Andreas -Andreas Krueger -- andreas.krueger (at) neuss.netsurf.de
-
- Matt -Matt -- mel63 (at) capital.net
-
- Reinald -Reinald S. Nielsen -- n984652 (at) hypernet.com
-
- Jeff -Jeff Renner -- nerenner (at) umich.edu
-
- Roland -Roland Salandha -- rsaldanh (at) magnus.acs.ohio-state.edu
-
- Dan -Dan Wing -- wagons (at) sover.net
-
- Jonathon -Jonathan Youngman -- jonathan (at) west.net
-
- Edited by Darrell Greenwood -- darrell.web (at) telus.net
-