SuperHack/SuperHack CD.bin/MISC/BREWINFO.ZIP/HOP.FAQ

Text File | 1994-05-01 | 40KB | 869 lines

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HOPS FAQ, Revision 3, 11/11/93
Compiled/edited by Norm Pyle ([e-mail])
Reviewed/edited by Mark Garetz ([e-mail])
Reviewed/edited by Al Korzonas ([e-mail])

I do not have the means to credit each passage individually, nor do I think it
would make for good reading were I to do so.  The following people (and
probably many more, sorry if I miss crediting you!) have contributed to this
FAQ (some of them don't even know they contributed!):

Glenn Anderson   ([e-mail])
Scott Barrett    (adiron!partech.com![e-mail])
Jeremy Bergsman  ([e-mail])
Jim Busch        ([e-mail])
Nick Cuccia      ([e-mail])
John DeCarlo     ([e-mail])
Alan Edwards     ([e-mail])
Bill Flowers     ([e-mail])
Mark Garetz      ([e-mail])
Russ Gelinas     ([e-mail])
Al Korzonas      ([e-mail])
Rick Larson      ([e-mail])
Don Leonard      ([e-mail])
John Palmer      (palmer#d#[e-mail])
Bob Regent       ([e-mail])
Peter Soper      (?)
Spencer Thomas   ([e-mail])
Glenn Tinseth    ([e-mail])
Patrick Weix     ([e-mail])
Carl West        ([e-mail])
Ed Westemeier    ([e-mail])
Dave Wiley       ([e-mail])
Gene Zimmerman   ([e-mail])

Business catalogs referenced:
The Hop Source   Silverton, OR
HopTech          Danville, CA
Hopunion USA     Yakima, WA

Authors referenced in the text:
Jackie Rager
Quentin B. Smith

Also, Messieurs Miller and Papazian should not be overlooked.  They have both
contributed indirectly to this FAQ.

I thank you and the HBD thanks you.  Here 'tis:

--

TABLE OF CONTENTS OF FREQUENTLY ASKED QUESTIONS ABOUT HOPS (TOCOFAQAH)

The following general topics are presented in this FAQ:

Definition of Hops
Description of Important Compounds
Forms of Hops
Bittering Units / Formulae
Storage
Growing Hops
Dry Hopping
Hop Back
Using Fresh Hops
Hop Varieties (Aroma)
Hop Varieties (Bittering)

--

Q:  What are hops?

A:  Hops are cultivated flowers (humulus lupulus) used for preservative and
flavoring characteristics in beer.  The bitterness of the hop is used to
balance the sweetness of the malt, and the essential oils add a flavor/aroma
which cannot be achieved by any other plant.  The hop plant is a perennial
spiraling vine which will grow in almost any climate given enough water and
sunlight.  It can climb either string or poles and can reach heights of over
25 feet.  The flowers (or cones as they are called sometimes) are usually
dried before use.

--

Q: What are the compounds which provide the bittering?  What about the aroma
compounds?

A: Read on:

Bittering Compounds

One of the major contributions hops give to beer is a characteristic
bitterness that provides a counterpoint to the rich sweetness provided by the
malt.  This bitter flavor is extracted from the hops during the boil.  It is
during this time that virtually insoluble alpha acids are isomerized
(rearranged without changing their composition) into more soluble and stable
iso-alpha acids, the main bittering substance in beer.  Five different
naturally occurring alpha acids have been isolated from hops which are:

humulone
cohumulone
adhumulone
prehumulone
posthumulone

Although isomerized alpha acids are the biggest contributers, hops contain
beta acids which also add bitterness to beer.  The beta acids are similar to
alpha acids both in structure and abundance.  In contrast to alpha acids, it
is not isomerized beta acids that add bitterness, is the oxidation products
of the beta acids, which are bitter and soluble, that make their presence felt.

Both the alpha and beta acids are very susceptible to oxidation, especially
at temperatures above freezing.  Theoretical losses of alpha acids of up to
60% have been calculated for hops which are packaged and stored poorly.  This
is important because once alpha acids have been oxidized they can no longer
be isomerized into iso-alpha acid, thus decreasing the hop's bittering
potential.  As stated above, oxidation components of beta acids contribute to
bitterness, thus the bittering potential of oxidized hops may not decrease as
much as is commonly thought.  This does not, in any way, argue against
storing hops well, since essential oil is dramatically altered by oxidation.

For these reasons, the "storageability" of each hop variety is often provided,
along with the alpha and beta acid levels, by the hop broker. This parameter
is usually given as a percentage of the alpha acids present after 6 months
at 20C.  Some good storage hops (usually high alpha acid) lose only 15-20%
of their alpha acids:  Cluster, and Galena are among the best.  Most high
quality aroma hops lose anywhere from 35-65% of their alpha acids unless
anaerobic conditions and cold storage (<0c) are provided.

This is why it is imperative for brewers to buy the freshest hops available
and store them in the freezer, properly packaged.

Essential Oils

Hops bring a lot more to beer than bitterness.  The volatile oil, usually
0.5 - 3.0% (vol/wt) of hop cone, is an important part of many types of beer.
Brewers seeking to maximize hop flavor and aroma generally make late kettle
additions (0-15 min.  before cooling) with high quality "aroma" hops.  Dry
hopping, i.e. the addition of hops to the secondary fermenter or serving tank,
is another way to add hop character to a beer although the aroma components
retained by this method differ from those obtained in late kettle additions.
The maximum oil utilization is about 10 - 15% which decreases with increased
boiling time.

The essential oils are what give hops their unique aroma; each variety has
its own distinct profile.  The smell of hops freshly crushed in your hand is
quite often different than that in a finished beer.  This is due to the fact
that the major components in hop oil, beta-pinene, myrcene, beta-caryophylene,
farnesene and alpha-humulene, are not usually found in beer.  However,
fermentation and the oxidation products of these compounds, especially
humulene epoxides and diepoxides are considered contributors to "hoppy"
flavors and aroma.  The exception here is with dry-hopping, where some of
the hop oil components do survive into the beer intact.

Researchers have not been able to duplicate the complexities of hoppy
character by adding pure chemicals in any proportion or combination.
Consensus is that there is a synergistic blend of several compounds, some
of which may have not yet been discovered.

Hop researchers, using capillary gas chromatography, have detected and
identified more than 250 essential oil components in hops.  Twenty two of
these have been pinpointed as being good indicators of hoppiness potential.
They are subdivided into 3 groups, humulene and caryophyllene oxidative
products, floral/estery compounds, and citrus/piney compounds, as listed below:

Oxidation Products:

caryolan-1-ol
caryophyllene oxide
humulene diepoxide a
humulene diepoxide b
humulene diepoxide c
humulene epoxide I
humulene epoxide II
humulene epoxide III
humulenol II
humulol

Floral/Estery Compounds:

geraniol
geranyl acetate
geranyl isobutyrate
linalool

Citrus/Piney Compounds:

delta-cadinene
gamma-cadinene
citral
limonene
limonene-10-ol
alpha-muurolene
nerol
beta-selenene

--

Q: Should I use pellets, or plugs, or loose hops?

A: Much has been written about what form of hops should be used. Loose hops are
just that:  loose cones which have been dried after picking.  Plugs are loose
hops which have been subsequently pressed into a bung, generally in 0.5 oz.
sizes.  Pellets are loose hops which have been ground to a fine powder and
then pressed into rabbit-food-sized pellets.

LOOSE HOPS
Advantages:  They are the most natural form of the ingredient.  They float,
which is good for siphoning out from under, and form a natural filter bed.
When they are fresh, they beat all others in terms of aromatic hop oils.

Disadvantages:  They float, so some contact with a still wort (as in dry
hopping) is lost, when compared to pellets.  This problem can be overcome,
though by using weighted hop bags, or it can be ignored.  Since they are loose,
exposure to air is the greatest and they lose quality quickly when compared to
the other forms of hops.  When stored in vacuum-sealed or CO2 or nitrogen
purged Oxygen barrier bags or jars, this problem can be avoided.  They are
bulkier than other forms.

PLUGS
Advantages:  Are nearly the same as loose hops, in that, when hydrated, they
become whole hop cones again.  Like loose hops, they float.  Unlike loose hops,
they are better protected from air.

Disadvantages:  Few hop varieties come in this form.  Currently, any domestic
varieties are first shipped to England where they are made into plugs and then
shipped back to the U.S.  This may negate any freshness advantage they have
over loose hops (for U.S. varieties)  It is difficult, but not impossible to
separate into increments smaller than 0.5 oz.

PELLETS
Advantages:  Convenient to measure and have the best protection from air.  They
sink, so they get maximum contact in a still wort, as when used for dry
hopping.  This advantage may be mitigated though, if they are subsequently
covered with dead yeast, so later additions are recommended.  They reportedly
contribute 10% more alpha acids to the wort because of maximized surface area,
so are a more efficient use of this relatively expensive ingredient.  They are
generally available in more varieties and are generally a more consistent
product.

Disadvantages:  They sink, so it is sometimes difficult to avoid them when
siphoning.  The extra processing may reduce/change hop aromatics.

Given the pros and cons listed, the choice of which form of hop to use in a
certain application is up the individual brewer.

--

Q:  What are AAU, HBU, and IBU's?

A:  Alpha Acid Units (AAU) and Homebrew Bittering Units (HBU) are the same.
For the sake of discussion we will use AAU's, which are calculated as follows:
AAU = AA * W

where AA = alpha acid % provided with the hops
       W = weight of the hops in ounces

AAU's are literally hundredths of an ounce, so the units would be ounces.
This is a bit awkward, and they are usually discussed as if they are
"unit-less".  It is generally assumed that, when using AAU or HBU, the batch
size is the standard homebrewing unit of 5 gallons.  If a beer is said to have
10 AAU's of bitterness in it, and it is a 5 gallon batch, there would probably
be no confusion.  On the other hand, if it is a 10 gallon batch, there is
actually half the AAU's per gallon when compared to the 5 gallon batch and the
beer would be quite different.  Another drawback to using AAU's is that they
don't consider the utilization obtained from long, intermediate, or short boil
times.  Fudge factors are sometimes added but at best they offer a rough
approximation.

To help solve these problems, the International Bittering Unit (IBU) may be
used.  With it, the brewer can get a more accurate approximation of the
bitterness given up by a given quantity of a given AA hop for a given boil
time.  It is independent of batch size so that a 5 gallon batch with 29 IBU's
has the same bitterness as a 50 barrel batch with 29 IBU's.  The equations are
commonly quoted from Jackie Rager's article in the Zymurgy "Hops and Beer"
Special Edition published in 1990.  The tables and formulae follow:

Boiling Time (minutes)   % Utilization
----------------------   -------------
less than 5                  5.0
 6 - 10                      6.0
11 - 15                      8.0
16 - 20                     10.1
21 - 25                     12.1
26 - 30                     15.3
31 - 35                     18.8
36 - 40                     22.8
41 - 45                     26.9
46 - 50                     28.1
51 - 60                     30.0

Utilization can be reduced to the following smooth function, as opposed to the
table, which produces many discontinuous lines.  Either can be used with
sufficient accuracy for the homebrewing operation.

%UTILIZATION = 18.10907 + 13.86204 * hyptan[(MINUTES - 31.32275) / 18.26774]
(Of course, you can drop some of those significant figures.)

    If the gravity of the boil exceeds 1.050:
ADJUSTMENT = (BOIL_GRAVITY - 1.050) / 0.2
    otherwise,
ADJUSTMENT = 0

IBU_PER_OZ  = %UTILIZATION * %ALPHA * 7462 / (VOLUME * (1 + ADJUSTMENT));
    UTILIZATION is the percent alpha acids expressed as a decimal fraction
    ALPHA is the percent alpha acids expressed as a decimal fraction
    VOLUME is the final number of gallons in the batch (usually 5).

    To calculate IBU's if you know the number of ounces of hops to be used:
IBU = OUNCES * IBU_PER_OZ
    To predict the number of ounces needed to hit a target IBU:
OUNCES = IBU / IBU_PER_OZ

Jackie Rager's numbers have been used successfully by hundreds of homebrewers
and provide a consistent base with which to work.  It is apparent that his
constant 7462, derived from metric to US conversion, is actually closer to
7490.  The ADJUSTMENT factor could be questioned as well, as it is
intuitively obvious that a gravity of 1.049 does not affect utilization
exactly the same as a gravity of 1.000 (water).  It is assumed that the
utilization table is corrected for this assumption and/or the difference is
small enough that it has little effect on the final bitterness of the beer.

Note also that Mr. Rager's numbers are often used for pellet hops thrown loose
in the boil.  Al Korzonas suggests adding 10% more hops if used in a hop bag,
and 10% more than that if loose hops or plugs are used.

It has been reported that since iso-alpha acids possess a slight electrical
charge, they can be lost in many ways.  Among these are absorption into the
yeast cell walls (and subsequent removal of the yeast), attachment to
coagulating proteins (and subsequent removal of this trub), attachment to
filters, etc.  It is unclear if Mr. Rager's utilization numbers have assumed
these losses.  A revised utilization table has been presented by Mark Garetz
and can be used if desired.  It is shown below for reference.

Boiling Time (minutes)   % Utilization
                         (adjusted for
                         average yeast)
----------------------   -------------
less than 5                   0.0
 6 - 10                       0.0
11 - 15                       1.0
16 - 20                       4.0
21 - 25                       6.0
26 - 30                      11.0
31 - 35                      13.0
36 - 40                      19.0
41 - 45                      23.0
46 - 50                      24.0
51 - 60                      25.0

The same IBU formulae from above can be used with this table.  It represents
one of the many arguable topics of hops in homebrewing.

--

Q:  How many IBUs should I shoot for in a beer with XXX original gravity?

A:  The AHA and probably other organizations publish (large) charts which
define the range of IBUs expected in a given style.  It is outside the scope of
this FAQ to go into that much detail on beer styles.  The following table
from an article titled "Matching Hops with Beer Styles" by Quentin B. Smith
in the 1990 Zymurgy Hops Special Issue may help.  The beer style has much more
to say about what the goal IBUs should be for a given beer, but this is a good
starting point:

Balanced Beer Hop Chart

Wort OG             IBU
-------             ---
1.010                4
1.020                8
1.030               12
1.040               16
1.050               24
1.060               32
1.070               40
1.080               48
1.090               56
1.100               64

--

Q:  How do I store my hops?

A:  At as low a temperature as possible, likely to be in your freezer.  Also,
attempt to remove as much air as possible from the package and use airtight,
preferably oxygen-barrier packages.

--

Q:  Can I grow my own hops?  How?

A:  Read this...

Hops for beer-making grow from the rhizomes of female hop plants.  Rhizomes
look like root cuttings but have buds growing from them that will become new
vines.  Rhizomes also contain stored nutrients to support initial growth.

Hops grow vertically as one or more vines that spiral up a twine or other
support.  Depending on latitude, location, and variety, they sprout from March
or April and grow through the summer and early fall.  A single plant can
easily grow 40 feet tall when it is mature but growth in the first year is
usually much less.  In most instances by the second or third year the plants
will exhibit full growth.  Height is very closely linked to the amount of
sunshine the plant gets.

Hops grow best in full sun and you should pick a spot with the best possible
southern exposure.  Hops grow best in loose, well drained soil.  Blended peat
moss and sand make a good growing environment.  In cases of poor soil
drainage, it can be helpful to create a mound of soil a foot or so tall which
will aid drainage.

Hops need lots of water.  As they grow be sure to give them a very good soaking
at least once a week.  There are reports that once-a-day waterings (up to 6.5
gallons per mound) give greater growth and yield.  Mulch in the summer helps
with weed control and also holds water.  Hops also have big appetites;
composted cow manure is an excellent well-balanced fertilizer for them.

Once a bed has been prepared the rhizomes are planted about 4 inches below
the soil surface with any obvious buds coming from the rhizome oriented to
point upward.

After several inches the new vines should be thinned so that just the most
healthy and vigorous three vines are left to continue growing.  This will be an
ongoing process as new shoots may show up later, but the initial thinning is
important.  It's been reported that the young shoots that are culled may be
steamed and eaten like asparagus.   On the other hand, some growers espouse
cutting the new shoots at all, allowing all vines to grow to full height.

As the vines grow over a foot tall they should be trained to grow up a twine.
This can be done by twisting the vine around the line.  This may have to be
repeated for a few days before the vine gets the idea.  Hops will have a
natural tendency to wrap clockwise looking down.

The most common hops trellis consists of strings running from the roof of a
building down to stakes driven into the soil near the plants.  Another option,
often used by commercial growers, consists of a large central pole, with
strings running from the top of the pole down to the foot of each plant,
similar to the spokes on a wheel.  Expect the string or twine to hold a lot of
weight as the vines grow tall.  A 25+ foot plant may weigh 20+ pounds.

Hop blossoms start out looking like large sand burrs, and then take on a
characteristic cone shape as they grow in size.  The size of a fully developed
cone depends on the variety, varying from 1 to 2 inches long by 1/2 to 1 inch
in diameter.

The hops are fully mature and ready for picking when two changes take place.
First, immature hops have a damp, soft feel and when squeezed slightly tend to
stay compressed.  Mature hops feel more like paper, spring back when squeezed,
and feel noticeably lighter.  The second key test is to pick an average example
hop and cut it lengthwise down the center with a knife.  When ready to pick,
the yellow powder (the lupulin sacs containing the essential oils and bitter
compounds) will be a dark shade of yellow, like the stripes on a highway, and
it will be pungent.  If a light shade of yellow then its likely the hops are
immature.

When ready to pick it is best to snip the stems of the cones with scissors or
a knife to avoid jarring the hops and knocking lupulin powder out or worse,
pulling the center of the cone out with the stem, causing a great loss of
lupulin.  Touching hops plants can cause skin irritation in some people;
gloves and long sleeves can help in this matter.

Just-picked hops are roughly 80 percent water; if left alone they spoil
rapidly.  For proper storage most of the water is removed by drying.  A good
drying method is to lie the hops on a card or screen in an attic.  Just a few
hours during the heat of summer or a few hours more in cooler weather is
enough to dry the hops.  Use a before and after weighing (and trial and error)
to try to achieve about 7-10 percent residual moisture after drying.

After drying, hops keep best at low temperatures and away from oxygen.  A
kitchen freezer easily takes care of temperature but to get the hops away from
oxygen is difficult.  Tightly packing hops in canning jars will minimize the
trapped air but be careful not to use too much force and break the all
important lupulin sacs since this accelerates oxidation.  Purging the canning
jar of oxygen by blowing in carbon dioxide from a kegging system will also
help prolong freshness.

It's common to get 4 or 5 harvests per year by picking the biggest, most
mature hops every 2 weeks or so as the flowers ripen.  Patience and judgement
are important since cones left on the vine too long turn brown and begin to
oxidize and spoil, while immature hops have little lupulin to give.

At the end of the growing season when the leaves have fallen or turned brown,
cut the vines at the surface of the soil and if possible remove the twine.
After cutting back the vines a layer of 3 or 4 inches of mulch and composted
manure can be put over the exposed vines for insulation and nutrition during
the winter.

Japanese beetles are the number one nuisance in many areas.  A common remedy
is to position a "Bag a Bug" type beetle trap about 30 feet directly up wind
from the hop vines.  There is some concern that the "Bag a Bug" traps may
actually attract more beetles than they catch, but that probably depends on
the situation.  Certain plants such as rose bushes may also attract the
beetles, so it's best to keep those plants away from your hops.  Also, the
beetles' larvae live in the ground, and in cases of extreme Japanese Beetle
infestation the surrounding lawn may need to be treated accordingly.  A
number of other pests, such as aphids, can harm hops, and can be treated with
any number of pesticides.  Since you will be consuming these hops, you should
use low toxicity natural pesticides, such as 1% Rotenone dust, for direct pest
control on the plants.  As with any consumable, you should ensure that any
pesticide is well washed before using the hops.

Ladybugs are the best, most natural way to get rid of aphids and a lot of other
bugs.  However, it can be difficult to keep them on your hop plants once you
run out of food for them.  A good idea is to plant some cilantro/coriander
between your hop hills.  Ladybugs are attracted to this plant and it will keep
their attention between feedings of aphids.  You can even harvest the cilantro
(the leaves) for cooking and use the coriander (the seeds) in Witbier.

One other hazard is animals.  A short fence of rabbit wire will keep cats,
dogs, rabbits, etc. at bay, but won't do much against deer.

Rhizomes are available from an increasing number of sources.  American
Brewmaster in Raleigh, NC and Freshops in Philomath, OR are two well-known
suppliers.  Cost is usually a few dollars each.  They should be kept in plastic
bags, moist and cold in your refrigerator until they are planted.

Additional information about hop growing can be found in "Homegrown Hops" by
David R. Beach.  Also, the 1990 special issue of "Zymurgy" is devoted to hops
and contains an article about growing hops by Pierre Rajotte.  The AHA also
has additional hops-oriented publications.

--

Q:  What is dry-hopping?  How do I do it?  How much do I use?  What variety?
What form of hops?

A:  Dry hopping can be defined as adding hops to a cooled wort at sometime
during the fermentation process.  It adds a fresh hops aroma/flavor to the beer
which cannot be matched with hop additions into hot wort.  It is not to be
confused with finish/aroma hopping, which is done on the hot wort while still
in the kettle.  The use of a hop-back, where hot wort is passed through the
hops, is another form of finish hopping; it is not dry hopping.  Dry hopping
gives little or no alpha acids to the wort, so it contributes little or no
bitterness to the final product.

There are several ways to dry hop, if one considers the variations of making
hop teas, etc.  The best time to dry hop is generally considered to be after
primary fermentation has slowed and little CO2 is being driven off the wort.
Dry hopping earlier than this point is inefficient as the volatile hop oils
are scrubbed away by the exiting CO2.  Also, if using pellets, dry hopping
early in the fermentation phase may result in the hops (which will sink to the
bottom) being covered with yeast and inefficient extraction of aroma.

The proper length of time for dry hopping is dependent on the temperature.  At
ale temperatures, 7-14 days of contact time is widely used.  At lager
temperatures, although little data is available, it seems obvious that longer
contact times, on the order of 14-21 days, are called for. It is common to use
0.5 - 2.0 oz. or more in a 5 gallon batch, but as always it is up the
individual's preferences.

Fuggles, Northern Brewer, Saaz, Cascades, all Hallertauer variants, and many
other hops have been used successfully.  It should be noted that the aroma of
the beer greatly influences the profile, and that the "correct" aroma hop should
be used to match the style (i.e. English hops for English ales, German hops for
German lagers, etc.).  American brewers have traditionally used hops from all
over the globe so European hops, for example, can be used without much fear of
an ungodly mismatch.  It should be noted that traditionally, German beers are
not dry-hopped but that American versions of German styles are sometimes dry
hopped.

The first and foremost way to dry hop is to simply put the hops into the
fermenter.  The most common worry with this method is about infecting a beer
which is nearly ready to bottle/keg.  Hops are natural preservatives, and
infections from this method are unheard of.  If loose hops or plugs are used,
they will float, and many use a sanitized hop bag and marbles to sink the hops
for maximum contact.  If pellets are used they will sink, but may be difficult
to avoid when bottling/kegging.  Also, the pellet hops can be easily covered by
yeast falling out of suspension, so they should be added after virtually all
fermentation activity has ceased, and a good amount of the yeast has fallen.

Another method used to dry hop is to steep the hops in a warm white alcohol
(grain, vodka, etc.) and sometimes water solution for hours or days, then pour
this solution into the fermenter.  This is a common practice among those who
want to protect against the remote possibility of infection with normal dry
hopping.  It should be noted that as the temperature of the alcohol/water/hops
mixture is raised, the effect approaches that of finish hopping, as the most
volatile hop oils are driven off.

Adding hop oil, a product recently introduced to the homebrewing market, is
another way of "dry-hopping".  It should be done after primary fermentation has
slowed for the same reasons.

These dry hopping methods, and others, will produce different results, mainly
because the desired compounds are so volatile.  The variety of reactions taking
place duration processing and fermentation will affect the results.  The "best"
method is the one which gives the desired result to the individual homebrewer.

A final note about dry-hopping:  the volatile hop compounds will react quickly
with oxygen.  For this reason, extra measures should be taken to avoid mixing
with air during bottling, in order to retain the hop aroma in the bottle for
extended periods of time.  These extra measures may include the use of CO2
purging the bottling vessel, very quiet siphoning, oxygen scavenging caps, and
possibly delayed capping (up to one hour).  This method allows any CO2 coming
out of solution during the bottling process to push the oxygen out of the
bottle before the caps are secured.  This method is used by some homebrewers
but the results are inconclusive.  The simplest method is to use the oxygen
scavenging caps, which requires no extra effort and little extra cost.  For
further reference, the Summer 1993 Zymurgy contains an article by Mark Garetz
on this subject.

--

Q:  What is a "hop-back"?  How is it used?

A:  A homebrewer's hop-back is a reservoir connected in-line between the kettle
and counter-flow chiller.  It is filled with fresh hops before the flow is
started.  The hot wort flows through the fresh hops and is quickly chilled by
the counter-flow before entering the fermenter.  Many of the volatile hop aroma
compounds are extracted and brought into the fermenter with this process.  It
is generally thought to produce a flavor/aroma profile somewhere between late
kettle additions and dry-hopping.

--

Q:  Can I use fresh hops rather than dried hops?  How much do I use?

A:  Yes, you can but at best it is a rough guess as to how much.  The rule of
thumb is to use 6 times as much (by weight) as you would dry hops.  A safer
rule would be to do this and to only use them for finish/dry hopping.  This is
because the AA% is unknown, and later additions are less sensitive to AA%.  It
should be noted that homebrewers have had mixed results when using fresh hops
(poor AA approximation for bittering, grassy aroma for finishing).

--

Q:  What varieties of hops are available to the homebrewer?  Where are they
grown? What do they taste/smell like?  Who uses them in commercial beers?
How much bitterness do they contribute?  How do I use them?  What are good
substitutes?

A:  The following table lists many common hop varieties available to the
homebrewer:

DISCLAIMER:  Hop substitutes should generally be thought of as "last resort"
options.  Some of them work better than others, and of course, the individual
brewer must decide which substitutes are best.  No attempt was made here to
label "good" and "not-so-good" substitutes, because the opinions vary wildly.

*******************************************************************************
The following hops are generally considered aroma hops although in recent years
they have started to gain a following in the homebrew community for bittering
as well:
*******************************************************************************

Name:         CASCADE
Grown:        US
Profile:      spicy, floral, citrus (esp. grapefruit) aroma
Typical use:  bittering, finishing, dry hopping for American style ales
Example:      Sierra Nevada Pale Ale, Anchor Liberty Ale & Old Foghorn
AA Range:     4.5 - 7%
Substitute:   Centennial

Name:         CRYSTAL (CFJ-HALLERTAU)
Grown:        US
Profile:      mild, pleasant, slightly spicy
Typical use:  aroma/finishing/flavoring
Example:      ???
AA Range:     2 - 5%
Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Mount Hood,
              Liberty.

Name:         EAST KENT GOLDINGS
Grown:        UK
Profile:      spicy (candy-like?) flavor;
              spicy/floral, earthy, rounded, almost pungent aroma
Typical use:  bittering, finishing, dry hopping for British style ales
Example:      Young's Special London Ale, Samuel Smith's Pale Ale, Fuller's ESB
AA Range:     5 - 7%
Substitute:   BC Goldings

Name:         FUGGLES
Grown:        UK, US, and other areas
Profile:      mild, soft, floral aroma
Typical use:  finishing / dry hopping for all ales, dark lagers
Example:      Samuel Smith's Pale Ale, Old Peculier, Thomas Hardy's Ale
AA Range:     4 - 5.5%
Substitute:   East Kent Goldings, Willamette

Name:         HALLERTAUER HERSBRUCKER
Grown:        Germany
Profile:      pleasant, spicy/mild, earthy aroma
Typical use:  finishing for German style lagers
Example:      Wheathook Wheaten Ale
AA Range:     2.5 - 5%
Substitute:   Hallertauer Mittelfrueh, Mt. Hood, Liberty, Crystal

Name:         HALLERTAUER MITTELFRUEH
Grown:        Germany
Profile:      pleasant, spicy, mild herbal aroma
Typical use:  finishing for German style lagers
Example:      Sam Adams Boston Lager, Sam Adams Boston Lightship
AA Range:     3 - 5%
Substitute:   Hallertauer Hersbrucker, Mt. Hood, Liberty, Crystal

Name:         LIBERTY
Grown:        US
Profile:      fine, mild aroma
Typical use:  finishing for German style lagers
Example:      Pete's Wicked Lager
AA Range:     3 - 5%
Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Mt. Hood,
              Crystal

Name:         LUBLIN
Grown:        Poland
Profile:      reported to be a substitute for noble varieties.
Typical use:  aroma/finishing
Example:      ???
AA Range:     2 - 4%
Substitute:   Saaz, Hallertauer Mittelfrueh, Hallertauer Hersbrucker,
              Tettnang, Mount Hood, Liberty, Crystal.

Name:         MT. HOOD
Grown:        US
Profile:      mild, clean aroma
Typical use:  finishing for German style lagers
Example:      Anderson Valley High Rollers Wheat Beer
AA Range:     3.5 - 5.5%
Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Liberty,
              Tettnang

Name:         NORTHERN BREWER
Grown:        UK, US, Germany (called Hallertauer NB), and other areas
              (growing region affects profile greatly)
Profile:      fine, fragrant aroma; dry, clean bittering hop
Typical use:  bittering and finishing for a wide variety of beers
Example:      Old Peculier(bittering), Anchor Liberty(bittering),
              Anchor Steam(aroma?)
AA Range:     7 - 10%
Substitute:   ???

Name:         SAAZ
Grown:        Czechoslovakia
Profile:      delicate, mild, floral aroma
Typical use:  finishing for Bohemian style lagers
Example:      Pilsener Urquell
AA Range:     3 - 4.5%
Substitute:   Tettnang (not ideal by any means)

Name:         SPALT
Grown:        Germany/US
Profile:      mild, pleasant, slightly spicy
Typical use:  aroma/finishing/flavoring, some bittering
Example:      ???
AA Range:     3 - 6%
Substitute:   Saaz, Tettnang

Name:         STRISSELSPALT
Grown:        France -- Alsace area
Profile:      medium intensity, pleasant, similar to Hersbrucker
Typical use:  aroma/finishing
Example:      ???
AA Range:     3 - 5%
Substitute:   Hersbrucker, German Spalt

Name:         STYRIAN GOLDINGS
Grown:        Yugoslavia (Fuggles grown in Yugoslavia), also grown in US
Profile:      similar to Fuggles
Typical use:  bittering/finishing/dry hopping for a wide variety of beers,
              popular in Europe, especially UK
Example:      Ind Coope's Burton Ale, Timothy Taylor's Landlord
AA Range:     5.5 - 7
Substitute:   Fuggles, Willamette

Name:         TETTNANG
Grown:        Germany, US
Profile:      fine, very spicy aroma
Typical use:  finishing for German style lagers
Example:      Gulpener Pilsener, Sam Adams Octoberfest, Anderson Valley ESB
AA Range:     4 - 6%
Substitute:   Saaz, Spalt

Name:         WILLAMETTE
Grown:        US
Profile:      mild, spicy, floral aroma
Typical use:  finishing / dry hopping for American / British style ales
Example:      Sierra Nevada Porter, Ballard Bitter, Anderson Valley Boont Amber
AA Range:     4 - 6%
Substitute:   Fuggles

*******************************************************************************
The following hops are generally considered bittering hops (note that the
examples given may not enlighten the taster as much as the aroma hops in the
previous section):
*******************************************************************************

Name:         BREWER'S GOLD
Grown:        UK, US
Profile:      poor aroma / sharp bittering hop
Typical use:  bittering for ales
Example:      ???
AA Range:     8 - 9%
Substitute:   Bullion

Name:         BULLION
Grown:        UK (maybe discontinued), US
Profile:      poor aroma, blackcurrant flavor when used in the boil
Typical use:  bittering hop for British style ales, perhaps some finishing
Example:      ???
AA Range:     8 - 11%
Substitute:   Brewer's Gold

Name:         CENTENNIAL
Grown:        US
Profile:      spicy, floral aroma, clean bittering hop (Super Cascade?)
Typical use:  general purpose bittering, aroma, some dry hopping
Example:      Sierra Nevada Celebration Ale, Sierra Nevada Bigfoot Ale
AA Range:     9 - 11.5%
Substitute:   Cascade

Name:         CHINOOK
Grown:        US
Profile:      heavy spicy aroma, strong bittering hop, astringent in large
              quantities
Typical use:  strong bittering
Example:      Sierra Nevada Celebration Ale, Sierra Nevada Stout
AA Range:     12 - 14%
Substitute:   Galena, Eroica, Brewer's Gold, Nugget, Bullion

Name:         CLUSTER
Grown:        US, Australia
Profile:      poor, sharp aroma, sharp bittering hop
Typical use:  general purpose bittering (Aussie version used as finishing hop)
Example:      Winterhook Christmas Ale
AA Range:     5.5 - 8.5%
Substitute:   Galena, Cascade, Eroica

Name:         EROICA
Grown:        US
Profile:      clean bittering hop
Typical use:  general purpose bittering
Example:      Ballard Bitter, Blackhook Porter, Anderson Valley Boont Amber
AA Range:     12 - 14%
Substitute:   Northern Brewer, Galena

Name:         GALENA
Grown:        US
Profile:      clean bittering hop
Typical use:  general purpose bittering
Example:      ???
AA Range:     12 - 14%
Substitute:   Northern Brewer, Eroica, Cluster

Name:         NUGGET
Grown:        US
Profile:      heavy, spicy, herbal aroma, strong bittering hop
Typical use:  strong bittering, some aroma uses
Example:      Sierra Nevada Porter & Bigfoot Ale, Anderson Valley ESB
AA Range:     12 - 14
Substitute:   ???

Name:         PERLE
Grown:        Germany, US
Profile:      pleasant aroma, almost minty bittering hop
Typical use:  general purpose bittering for all lagers except pilsener
Example:      Sierra Nevada Summerfest
AA Range:     7 - 9.5%
Substitute:   ???

Name:         PRIDE OF RINGWOOD
Grown:        Australia
Profile:      citric aroma, clean bittering hop
Typical use:  general purpose bittering
Example:      ???
AA Range:     9 - 11%
Substitute:   ???

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