Colossal Cookbook/ColossalCookbook.cdr/beer/2879/rims.txt

Text File | 1991-01-20 | 22KB | 419 lines

Rodney Morris [75046,350]

Recirculating Infusion Mashing System
by Rodney Morris

Introduction

I developed this mashing system because I was dissatisfied with the ì
traditional "pot on a stove" which I had used previously.

This system was developed to have the following features:

1.  Precise temperature control to within +/- 0.1! C so as to give repeatable ì
mashing conditions from batch to batch.  If a particular beer made with thisì
system is a bit too dry, I could precisely adjust the mash temperature a fewì
degrees on the next batch  to change the ratio of fermentable to non¡
fermentable carbohydrates.

2.  Uniform temperature throughout the mash.  The old system heated the maltì
in the pot in a non-uniform manner, with precise temperature controlì
difficult.

3.  Reduction of labor in mashing.  There is no need to stir the pot during aì
temperature boost.

4.  Faster mashing than the old method.

5.  Recirculation of the wort in the new method produces a brilliantly clearì
liquid by the end of the final temperature rest.  Formerly, it was necessaryì
to transfer the mash to a lauter vessel and then drain and recycle some of theì
wort repeatedly until the wort ran clear.

6. Mashing and sparging is done in one vessel.

Items Required

Igloo Legend 36 quart cooler- If you mash 8 to 10 gallon batches, use a 48ì
quart cooler.

A stainless steel open bottomed box which just fits in the cooler.  I bought aì
sheet of 20 guage stainless steel, nine inches wide and long enough to bendì
into the box shape for $12 from a local sheet metal supplier.  A flange 3/8"ì
wide was bent inwards on the bottom of the box to support an 18 mesh stainlessì
steel screen which was held in place by pop rivets.

Two 5/16" diameter rods were run lengthwise of the box below the screen andì
welded to the bottom of the box to hold it just above the cooler surface.  Theì
bolting grade type 304 stainless steel screen has 70% open area, allowing aì
very fast recirculation of the wort.  If you use any other type of mashì
support, be certain it allows rapid recirculation. The screening is availableì
from :

McMaster-Carr (main office)
P. O. Box 4355
Chicago Il 60680-4355
Orders: 312-833-0300
Los Angeles, CA office sales 213-692-5911
Dayton, NJ office sales 201-329-3200
Catalog # 9230T72, $4.42 per square foot

The screening comes in 3 or 4 foot wide rolls and is sold in linear feet.  Iì
bought enough to make several mash boxes.  This company prefers purchaseì
orders.  Ask for their 1000 page catalog of industrial products, which hasì
many items useful for microbrewery construction.

A small magnetic drive pump with a heat resistant pump housing was used toì
recirculate the wort.  Check surplus dealers in your city for such pumps.  Theì
selection criteria are:

1. Magnetic drive, no shaft to leak wort into the motor.
2. Pump housing connections for 1/2" diameter hose.
3. Pump capacity of four to eight gallons per minute at a one foot head.
4. Universal type motor capable of being speed controlled by a triac motorì
controller.  All pumps I have examined can be speed controlled.
5. Motor power of 1/50 to 1/20 horse power, with 1500 to 3000 RPM.
6. Shut off pressure of pumping at 6 to 20 feet of head.
7.Heat resistant pump head.

Companies which make suitable pumps include March Manufacturing Co., Miltonì
Roy, and Little Giant.  I recommend those made by March if possible.

The original recirculating pump was bought from:
Edmund Scientific Co.
101 E. Gloucester Pike
Barrington, NJ  08007-1380
Orders: 609-573-6250

The surplus pump, which cost $24, is no longer available.

After searching for some time, I found that a similar low-cost surplus pumpì
was available from:

H&R Corporation
401 E. Erie Ave.
Philadelphia, PA 19134
Orders: 214-425-8870

Unfortunately, this pump has also been sold out. They do get in additionalì
surplus pumps from time to time, so you might request a catalog from themì
which has pumps listed in it.

I have finally located two companies which routinely carry such pumps, but notì
at surplus prices.

Cole Palmer Instrument Co.
7425 North Oak Park Ave.
Chicago, Il  60648
Orders 800-323-4340

They have the biggest variety of pumps anywhere at full retail price.  Theyì
also sell service kits for the magnetic drive pumps.  A March MDX pump, Cat.ì
No.  N-07004-10 sells for $104.00.

If you mash 8-10 gallon batches in a 48 quart cooler, use the higher capacityì
MDX-3 pump, Cat. No. N-07004-30, price $111.00.  Cole Palmer accepts creditì
card phone orders.

W. W. Grainger, Inc.
5959 W. Howard St.
Chicago, Il 60648
800-323-0620

They sell pumps and many industrial items at wholesale prices.  They have overì
225 branches nationwide.  Call them for the nearest branch to you.  Also askì
for their 1600 page catalog, which has many items of use to microbreweries. ì
They sell the March MDX pump, Cat. No. 1P676 for $60.87, and the MDX-3 pump,ì
Cat. No. 1P677 for $66.82.

The mash heating element, R5 in the circuit diagram, is a nickel alloy lowì
density 240 volt, 4500 watt heating element for electric water heaters.  It isì
run at 120 volts, giving 1100 watts of heat.  Use only this type of heater,ì
with a 15" long element, with the loop folded back most of its length to haveì
a low heat density.  Tin plated copper heating elements are not recommendedì
because of their high heat density which can scorch the wort on the heatingì
element.  I purchased the heating element form a local buildingì
supply/hardware store for $11.78.  Use the screw-in type.  If you mash 8-10ì
gallon batches of beer, use a 5500 watt heater with a March MDX-3 pump and aì
48 quart cooler.

Use a 1-1/2" diameter by 15-1/2" long copper plumbing pipe to hold the heater. ì
The ends of the pipe are closed with copper pipe caps. One cap has a 1" holeì
to admit the heating element. A 1" copper threaded coupling is mounted on this
end to accept the screw-in heating element.  At one end, a copper 1/2" T isì
attached to receive the wort from the pump.  The other end has a 1/2" elbowì
attached at the top to carry the heated wort back to the top of the grain inì
the cooler.  All of the copper parts cost me  a total of $12.  Some plumber'sì
suppliers quoted me much  more than the one from which I finally bought theì
copper items.  See figures 3 and 4 for construction details of the heaterì
tube.  Do not use a larger diameter tube, since it would result in the wortì
flowing more slowly past the heater element and being over heated.

Figure 1 is a circuit diagram of the temperature controller.  At points A andì
B you may connect either of the two power indicator circuits shown at the top. ì
The meter circuit will show the average power being used to heat the mash. ì
H&R corporation sells surplus meters for about $5.  If you use this meterì
power circuit, the scale must be recalibrated to show the average powerì
accurately.  The motor speed controller circuit shown in figure 2 may beì
constructed using the components shown or a similar controller may beì
purchased from H&R Corporation for $4.  Do not use a light dimmer since theì
inductive load may cause it to fail.  You can convert a light dimmer to aì
motor speed controller by connecting a snubber consisting of R15 and C7 acrossì
the triac.  Use only a low power CMOS type 555 timer in the circuit, since the
current available from the CA3059 is insufficient to power a conventional 555ì
timer.  The TLC 555  CMOS timer is available from Radio Shack.  The 120 voltì
neon indicator is also available from Radio Shack.  Most of the components are
available from:

Digi-Key Corporation
701 Brooks Ave South
P. O. Box 677
Thief River Falls, MN  56701-0677
800-344-4539

GFCI is a 15 ampere ground fault circuit interruptor wall outlet which Iì
obtained from a local hardware store for $8. Do not pay more than $20 for thisì
item.

R3 may be a single turn potentiometer (Radio Shack) or a 10-turn precisionì
potentiometer and counter knob from a surplus dealer ($5 each).  The 10-turnì
potentiometer allows one to precisely set the desired temperature, but isì
expensive unless purchased from a surplus dealer.  R4 is the thermistor whichì
allows the CA 3059 to control the temperature of the wort.  Use a small sizeì
(0.1" diameter) bead type thermistor available from Digi-Key.  Solder theì
leads of the thermistor to two small wires.  Coat the thermistor and bareì
leads with a thin layer of epoxy cement. When the epoxy has hardened, insertì
the thermistor into a short piece of thin wall brass tubing which is slightlyì
larger in diameter than the thermistor bead.  The brass tubing is filled withì
epoxy and allowed to harden. Use only brass tubing which is slightly largerì
than the thermistor bead so that a rapid response to temperature changes inì
the wort is possible.  Make certain that the wire leads of the thermistor areì
not shorted to the brass tubing.  A convenient source of small size brassì
tubing is from ball point pens.  The thermistor is inserted through a smallì
hole in a rubber stopper at the inlet to the heater.  An accurate digitalì
temperature display is available from Radio Shack, Cat. No. 63-841 for $13. ì
Remove the circuit board from the case and unsolder the tiny thermistor beadì
which is located underneath the slots in the front panel of the unit.  Mountì
this thermistor in another piece of brass tubing as was done with the otherì
thermistor.  Mount this thermistor in another hole in the rubber stopper.  Runì
the wire leads back to the themometer board and solder the ends to theì
location from which you removed the thermistor.  This thermometer will displayì
Celsius or Fahrenheit.  It will also show the time with a push of a button. ì
My unit has an error of of 0.3! C.  There is no temperature calibrationì
adjustment in this unit.  The maximum temperature displayed is 69.9! C.  Aì
larger digital thermometer with a remote probe included is available fromì
Edmund Scientific for $20.  This unit reads to 199.9! (Fahrenheit only) andì
has a temperature calibration potentiometer on the circuit board.

Parts List
All resistors are 1/4 watt, 10% unless indicated otherwise.
R1    8.2 K, 2 watt film type
R2    5.6 K
R3    50 K linear potentiometer, single or 10 turn
R4    100 K NTC thermistor, Digi-Key Cat. No. KC009N-ND, $2.04
R5    4500 watt, 240 volt nickel alloy (Incoloy) low heat density hot water
        heater element
R6    130 K
R7    100 ohm
R8    47 K
R9    10 M ohm
R10    1.8 K
R11    510 K, adjust for full scale on meter at maximum heating
R12    2.2 K, 1/2 watt
R13    100 K linear potentiometer
R14    15 K
R15    1 K, 1/2 watt
C1    220 uF, 16 volt electrolytic
C2    22 uF, 16 volt low leakage electrolytic or tantalum type
C3    .01 uF, 50 volt ceramic
C4    10 pF, 50 volt ceramic
C5    0.1 uf, 200 volt mylar
C6    0.1 uf, 100 volt mylar
C7    0.1 uf, 250 volt mylar
C8    0.1 uf, 250 volt mylar
C9    2200 uf, 6 volt electrolytic
D1    1 amp, 600 volt rectifier
D2    Diac trigger for triac, or use a triac with a built in diac (quadrac)
S1    15 amp SPST switch
T1    15 amp, 400 volt triac with an isolated tab, Digi-Key Cat. No.
        Q4015L5, $2.25
T2    4 amp, 400 volt triac or quadrac, Digi-Key Cat. No. Q4004LT, $1.75
M1    100 uA DC meter
MOT    pump motor
L1    100 uH choke (200 turns of 20 ga. wire wound on 1- 1/2" x 1/2" ferrite
        rod)
Neon    120 volt panel mount neon indicator with built-in resistor
GFCI    15 amp Ground Fault Circuit Interruptor Outlet
CA 3059    Temperature controller, Digi-Key Cat. No. CA3059,  $1.53
TLC 555    CMOS type 555 timer, Radio Shack Cat. No. 276-1723, $1.19

Mount the T1 triac on a 2" x 4" finned aluminum heat sink with thermalì
compound between the triac and the heat sink, since it dissipates considerableì
heat.  Use an isolated tab type of triac so that the heat sink does not becomeì
electrically live. The CA 3059 temperature controller uses zero voltageì
switching to eliminate radio frequency interference.  It operates directly ofì
of the 120 volt AC line, with no transformer power supply needed.  Theì
temperature controller circuit uses proportional control to hold the wortì
temperature within +/- 0.1! C, actually better than is necessary.  Theì
controller anticipates the set point temperature when you boost it after aì
mash rest, and automatically starts to reduce the heating power at 1.5! Cì
before the set point, preventing over shooting the desired wort temperature. ì
At the set point, the average power needed to maintain temperature is about 60ì
watts.  The wort should be recirculated at least 2.5 gallons per minute duringì
maximum heating in the temperature boost periods.  The temperatureì
differential between the input and output of the heater should be 2! C. orì
less with maximum power.  Recirculation may be slowed during the rest periods. ì
A sheet of 1/8" thick styrene plastic with 250 1/8" holes drilled in it is cutì
to just fit the box and  is laid on top of the mash.  This prevents the streamì
of wort from the heater from stirring up the mash.

Figure 6 shows the connector made from copper tubing to replace the plasticì
spigot which comes with the cooler.

Safety Considerations

Use this RIMS unit only on three wire grounded circuits.  The unit must have aì
ground wire attached to the heater tube and the case of the pump motor.  Theì
ground will protect against shorts in the equipment.  Use a GFCI type outlet,ì
since it will trip at about 5 milliamperes, unlike a conventional circuitì
breaker.  If a GFCI is not used, touching a 120 volt wire in the RIMS unit mayì
allow enough current to flow through your body to ground to kill you withoutì
tripping a conventional circuit breaker or fuse.

Assemble the copper tubes with only lead free solder.  KMart sells smallì
spools of lead free 96% tin/4%silver or 95%tin/5% antimony solder.

Tips For a Better Beer

Now that you can have precise temperature control for mashing, here are someì
suggestions for improving your beers.  The ratio of water to grain in yourì
mash will affect the mash enzymes.  Measure the water and weigh the grain soì
as to produce the style of beer you like.  Check and adjust the pH of theì
mash, as the pH level will affect the enzymatic reactions.  I recommend theì
plastic "colorpHast" strips sold in better brewing supply stores.  Use Cat.ì
No. 9582, pH range of 4.0 to 7.0.  The indicator dye does not wash out of theì
test strips.  With weakly buffered solutions such as wort, immerse the testì
strip for one minute before reading.  You can also buy boxes of 100 testì
strips from scientific supply houses for $8.  I do not recommend the pen typeì
pH meters which sell for about $80.  They have no temperature compensation andì
have considerable drift, making them no more accurate than pH test strips.  Aì
decent pH meter with stability and temperature compensation costs about $200.
The salts in your mash and sparge water will also affect the type of beer youì
make.  Adjust the sparge water to the same range as wort (around pH 5-5.5)ì
with phosphoric or lactic acid to reduce the amount of tannins leached fromì
the barley husks during runoff.  Two row rather than six row barley for allì
barley malt beers is preferred, since the high proportion of husks in the sixì
row variety produces excessive tannins in the wort.

Do not grind the grain too finely in a hand mill.  Excess flour slows theì
recirculation rate too much, resulting in scorching of the wort on the heater. ì
I use a roller mill with 8" rollers to give a medium crush.  I monitor theì
mash development with a hand-held refractometer to determine when to cease andì
start sparging. The refractometer is faster and more convenient than aì
hydrometer.  Unfortunately, refractometers are expensive, with a price aroundì
$175.  A refractometer is unsuitable for determining the gravity of aì
fermented beer, due to the dramatic effect the alcohol has on the refractiveì
index.  I  can use this effect to measure a fermented beer with aì
refractometer and hydrometer to determine the residual gravity, the originalì
gravity, the alcohol content and the final gravity of a beer.  Do not exceedì
75! C with the sparge water, since very hot water may warp the plastic of theì
cooler and gelatinize remaining starch which could then cloud the wort runoff. ì
A decoction mash has little problem with hot (80! C) sparging, since portionsì
of the mash are boiled and little starch remains at the end of mashing.  I useì
a 1 kilowatt stainless steel heater unit which hangs on the rim of my spargeì
water pot and has a thermostatic probe to maintain the sparge water at 72! toì
75! C.  I bought this nice heater from H&R Corporation for $9.95.

Leave the hot break trub and cold break behind when you fill the fermenter. ì
Aerate (rouse) the cold wort so the yeast fermentation will get a fast start.ì
Use a clean, vigorous yeast starter and do not ferment at too high aì
temperature.

Projects Underway

I am now developing a boil over detector which clips on the side of the wortì
boiling pot and sounds an alarm when the foam rises at the beginning of theì
boil.  This battery powered detector costs under $5 and should preventì
boilovers from unwatched brew pots.  I am also developing a 2750 wattì
immersion heater for my brew pot that has adjustable heating power from 0 toì
100%.  This heater is expected to cost under $30. With my electric rates, itì
will cost 10 cents an hour to operate.   Good luck in your brewing!

Additional information on the RIMS system

1. The circuit diagram for the system is accurate.  Various homebrewers haveì
constructed the device and found it to work.  Check your circuit boardì
carefully for wiring errors before turning it on and doing a smoke test.

2. Use a ground fault circuit interruptor (GFCI) type of outlet for safety,ì
since an electrical hazard will result if you spill wort onto the electronicì
components, etc.  A GFCI  outlet sells for $7.88 on sale at an area hardwareì
store, so safety is not expensive.

3.  Cheap recirculating pumps are not readily available.  Do not substitute aì
pump with a slow flow rate for the suggested types, even if they are cheapì
(for example, a pump used in evaporative coolers for homes).  Check industrialì
surplus stores for good, inexpensive pumps.  I have found another surplusì
company that sells a pump, when modified, will work.

     C&H Sales Co.
     2176 E. Colorado Blvd.
     Pasadena, CA  91107
     Phone [phone]
     Stock #PC8402      $39.95

This magnetic drive pump has a brass, heat-resistant head which pumps at 2.3ì
GPM, a little slow.  You can use an autotransformer to increase the flow rateì
sufficiently  for use with the RIMS system.  Buy a small 120 to 12 volt center
tapped transformer rated at 2 amperes on the low voltage side.  Connect the 12ì
volt windings in series with the 120 volt windings.  Wire the transformer withì
the line voltage connected to the 120 volt terminals, and connect the pump toì
the series connected windings through a switch to select 120 volts, 126 volts,ì
or 132 volts as needed to control the speed of the pump motor.  Do not use theì
electronic speed controller with this setup.

4.  Add about 1.3 quarts of water per pound of grain to the cooler and heat itì
to about 6 degrees Celsius above the desired strike point.  When you haveì
reached the desired temperature, turn off the heater, then add the grain whileì
pumping.  Continue to pump for about 10 minutes, whereupon the grain will packì
down and the flow rate will decrease.  Stir up the grain bed with a largeì
spoon, continue pumping for about 2 minutes, then turn the heater back on.  Iì
do not need to stir up the grain bed more than twice during a mashing sessionì
to keep a high flow rate through the grain bed.  Mash out about 10-20 minutesì
after the starch particles have digested and the recirculating liquid isì
clear.

5.  If the barley was ground too fine,the result will be a "set mash", whichì
is a mash in which the lauter run-off is slow or stopped.  Crush the grain, doì
not grind too finely.

6.  If a large, strong suction pump is used without a box to hold the grain,ì
it can cause the grain bed to be compacted, reducing the flow rateì
excessively.  Also,if the pump is too far below the grain bed,it may result inì
a strong hydrostatic head suction which compacts the grain bed and reduces theì
flow of wort through the grain.  The inlet of my pump is two inches above theì
bottom of the screen.  Also, I designed the RIMS unit so the box has a smallì
gap between the box and the walls of the cooler.  The maximum hydrostatic headì
is limited by the depth of the grain bed, never more than 9 inches.  The wortì
flows through the grain without suction into the bottom of the cooler to aì
depth of about 1-2 inches, where it is drawn into the pump.

7.  If a box is not used to hold the grain in the insulated cooler, you canì
limit the hydrostatic head to the depth of the grain bed by verticallyì
securing a piece of 1-1/2 inch diameter by one foot long piece of PVC sinkì
tailpiece to the false bottom screen with wire to exclude grain inside theì
tube.  If the pump runs too fast, air will be drawn into the pump, but theì
grain bed should not be compacted.

8.  Use sufficient water for mashing.  Various technical homebrewing books byì
Noonan, Miller, Dr. Fix, etc. recommend a ratio of 1.25 to 1.5 quarts of waterì
per pound of grain as typical for mashes.  The RIMS unit works well with aboutì
1.25 to 1.33 quarts of water per pound of grain.  Miller considers 1.33 quartsì
per pound of grain in his step infusions to be a "stiff" mash.

9.  Do not have the grain bed over one foot deep.  Commercial brewers may haveì
deeper beds during the lauter period, but they continually stir the top of theì
mash beds during the lauter operation to keep the liquid flowing fast enough.

10.  I have some extra CA3059 I. C.s for those who need them  (until they runì
out).