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HOMEBREW Digest #1214
This file received at Sierra.Stanford.EDU 93/08/30 00:50:29
HOMEBREW Digest #1214 Mon 30 August 1993
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Rob Gardner, Digest Coordinator
Contents:
yeast faq 4 of 8 (WEIX)
yeast faq 5 of 8 (WEIX)
yeast faq 7 of 8 (WEIX)
yeast faq 8 of 8 (WEIX)
yeast faq 6a of 8 (WEIX)
yeast faq 6b of 8 (WEIX)
yeast faq 2 of 8 (WEIX)
septic systems and bleach and yeast (KEN SEGAL EXT. 8920)
NOEL@????.hp.com (Mike Zentner)
Whats Weihenstephan??! (Jim Busch)
Labels and whining (mine) (Tim Anderson)
Mark at Lotus (korz)
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----------------------------------------------------------------------
Date: Thu, 26 Aug 1993 16:24:25 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 4 of 8
Yeast Culture Kit A01
From California. Vendor's suggested uses (VSU): Barley Wine, Brown Ale, Pale
Ale, India Pale Ale, Cream Ale, Porter, Stout.
Yeast Culture Kit A04
From Oregon. VSU: Dusseldorf Altbier, Kolsch.
Yeast Culture Kit A06
From Oregon. VSU: Porter, Stout, Imperial Stout.
Yeast Culture Kit A08
From Dorchester, England. VSU: Barley Wine (high residual sweetness).
Yeast Culture Kit A13
From Ireland. VSU: Porter, Stout, Imperial Stout.
Yeast Culture Kit A15
From England. VSU: Brown Ale, Pale Ale, India Pale Ale, Cream Ale, Bitters
and Milds.
Yeast Culture Kit A16
From Belgium. VSU: Trappist Ales (Abbeys, Doubles, Tripples).
Yeast Culture Kit A17
From London, England. VSU: Brown Ale, Pale Ale, India Pale Ale, Cream Ale,
Bitters and Milds.
Yeast Culture Kit A34
From Edinburgh, Scotland. VSU: Barley Wines, Scotch Ale, Scottish Bitters,
Strong Ale.
Yeast Culture Kit A35
From cental Belgium. VSU: Belgian Whites.
Yeast Culture Kit A36
From Houffalize, Belgium. VSU: Belgian Ales.
Yeast Culture Kit A37
From Bavaria, Germany. VSU: Altbier, Kolsch.
Yeast Lab A01 Australian Ale Yeast
This all purpose strain produces a very complex woody and flavorful beer.
Australian origin. Medium attenuation, medium flocculation. Great for Brown Ales
and Porters.
Yeast Lab A02 American Ale Yeast
This clean strain produces a very fruity aroma, with soft and smooth flavor
when fermented cool. Medium attenuation and low flocculation. This is an all
purpose ale yeast.
Yeast Lab A03 London Ale Yeast
Classic Pale Ale strain, very dry. A powdery yeast with a hint of diacetyl
and rich minerally profile, crisp and clean. Medium attenuation and medium
flocculation.
Yeast Lab A04 British Ale Yeast
This strain produces a great light bodied ale, excellent for Pale Ales and
Brown Ales, with a complex estery flavor. Ferments dry with a sharp finish.
Medium attenuation and medium flocculation.
Yeast Lab A05 Irish Ale Yeast
This top fermenting strain is ideal for Stouts and Porters. Slightly acidic,
with a hint of butterscotch in the finish, soft and full bodied. Medium
attenuation, high flocculation.
Yeast Lab A06 Dusseldorf Ale Yeast
German Altbier yeast strain finishes with full body, complex flavor and spicy
sweetness. Medium attenuation, high flocculation.
Yeast Lab A07 Canadian Ale Yeast
This strain produces a light bodied, clean and flavorful beer, very fruity
when fermented cool. High attenuation, medium flocculation. Good for light and
cream ales.
Yeast Lab A08 Trappist Ale Yeast
This is a typical Trappist strain, producing a malty flavor with a balance of
fruity, phenolic overtones when fermented warm. Alcohol tolerant, high
attenuation and high flocculation.
PART 3: LAGER YEAST (SACCHAROMYCES UVARUM)
Dry Lager Yeast:(generally not recommended--tend to be inconsistent).
Liquid Lager Yeast: Much preferred over dry types!
BrewTek CL-60 Original Pilsner
Leaves a full bodied Lager with a sweet, underattenuated finish with a
subdued diacetyl character.
BrewTek CL-62 American Megabrewery
A strong fermenter, leaves a light, crisp, almost dry finish to Lagers.
Produces a good strong Lager.
BrewTek CL-64 Carlsbergenis
A Scandinavian Lager strain which leaves a full flavored, slightly sweet and
malty profile.
BrewTek CL-66 N. German Lager
Exhibits a clean, crisp, traditional Lager character. A strong fermenting and
forgiving Lager yeast.
BrewTek CL-68 East European Lager
Imparts a smooth, rich, almost creamy character, emphasizing a big malt
flavor and clean finish.
BrewTek CL-86 California Esteem
Use to recreate "California common beers" leaves a slightly estery, well
attenuated finish.
Wyeast 2007 Pilsen Lager Yeast
Our original Lager Yeast Strain. Specific for pilsner style beers. Ferments
dry, crisp, clean and light. Medium flocculation. Apparent attenuation from
71-75%. Optimum fermentation temperature: 52 deg. F (11 deg. C). It is worth
mentioning that this yeast strain is reportedly used quite a bit in St. Louis,
if you know what I mean ;^).
Wyeast 2035 American Lager Yeast
Unlike American pilsner styles. It is bold, complex and woody. Produces
slight diacetyl. Medium flocculation, apparent attenuation 73-77%. Optimum
fermentation temperature: 50 deg. F (10 deg. C). This yeast allegedly is the one
used by August Schell in New Ulm, MN.
Wyeast 2042 Danish Lager Yeast
Rich, yet crisp and dry. Soft, light profile which accentuates hop
characteristics. Flocculation is low, apparent attenuation is 73-77%. Optimum
fermentation temperature: 48 deg. F (9 deg. C).
Wyeast 2112 California Lager Yeast
Warm fermenting bottom cropping strain, ferments well to 62 deg. F (17 deg.
C) while keeping lager characteristics. Malty profile, highly flocculant, clears
brilliantly. Apparent attenuation 72-76%. Allegedly, the Anchor steam yeast.
Wyeast 2124 Bohemian Lager Yeast
Ferments clean and malty, rich residual maltiness in high gravity pilsners,
medium flocculation, apparent attenuation 69-73%. Optimum fermentation
temperature: 48 deg. F (9 deg. C). Allegedly, one of the four (?) Pilsner
Urquell yeasts.
Wyeast 2206 Bavarian Lager Yeast
Lager yeast strain used by many German breweries. Rich flavor, full bodied,
malty and clean. Medium flocculation, apparent attenuation 73-77%. Optimum
fermentation temperature: 48 deg. F (9 deg. C).
Wyeast 2308 Munich Lager Yeast
Lager yeast from Wissenschaftliche in Munich #308. One of the first pure
yeast available to American home brewers. Sometimes unstable, but smooth soft
well rounded and full bodied. Medium flocculation, apparent attenuation 73-77%.
Optimum fermentation temperature: 50 deg. F (10 deg. C). One report of an
intense off aroma (like home perm solution) with this yeast fermented at 45-50F,
but it miraculously disappeared after four months aging in the bottle at 40F.
Yeast Culture Kit L09
From Bavaria, Germany. VSU: American Dark Lager, American Lager, Bavarian
Dark, Doppelbock, Dortmund/Export, Eisbock, German Bock, German Lagers, German
Schwarzbier, Hellesbock, Munich Helles, Marzen/Octoberfest, Pilsner. (Must be
some yeast! :-)
Yeast Culture Kit L17
From Pilsen, Czechoslovakia. VSU: American Lagers, Bohemian Pilsner.
------------------------------
Date: Thu, 26 Aug 1993 16:24:40 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 5 of 8
Yeast Lab L31 Pilsner Lager Yeast
This classic strain produces a light lager in both flavor and body,
fermenting dry and clean. High attenuation and medium flocculation.
Yeast Lab L32 Bavarian Lager Yeast
Use this classic strain for medium bodied lagers and bocks, as well as Vienna
and Marzen styles, rich in flavor with a clean, malty sweetness. Medium
attenuation and medium flocculation.
Yeast Lab L33 Munich Lager Yeast
Wissenschaftliche strain for medium bodied lagers and bocks, subtle and
complex flavors, smooth and soft, a hint of sulfur when fresh. Medium
attenuation and medium flocculation.
Yeast Lab L34 St. Louis Lager Yeast
This strain produces a round, very crisp and clean fruity flavor, with medium
body. High attenuation and medium flocculation. Good for American style lagers.
Yeast Lab L35 California Lager Yeast
A California common beer strain, malty with a sweet woody flavor and subtle
fruitiness. Medium attenuation and high flocculation.
PART 4: WEISSEN, LAMBIC, MEAD, AND BARLEYWINE STYLES.
BrewTek CL-90 Belgian Wheat
A top fermenting yeast which produces a soft, bread like flavor and leaves a
sweet, mildly estery finish.
BrewTek CL-92 German Wheat
A true, top fermenting Weizenbier yeast. Spicy, clovy and estery. Highly
attenuative.
BrewTek CL-94 American Wheat
Offers a smooth, slightly sweet wheat beer, with a full, clean,
underattenuated malt flavor.
BrewTek CL-100 Brettanomyces Lambicus
Use to create Belgian Lambic beers. Added after primary fermentation with a
regular ale yeast.
Wyeast 3056 Bavarian Weissen Yeast
A 50/50 blend of S. cerevisiae and delbrueckii to produce a south German
style wheat beer with cloying sweetness when the beer is fresh. Medium
flocculation, apparent attenuation 73-77%. Optimum fermentation temperature: 56
deg. F (13 deg. C). Problematic to get the right flavor, often just produces
relatively unattenuated beer, without the clove-like aroma/flavor. Perhaps it's
the freshness of the Wyeast #3056 that makes the difference in whether you get
the clove-like aroma/flavor or not.
Yeast Culture Kit M01
From Bavaria, Germany. VSU: American Wheat, Dunkel Weizen, German Weizen,
Weizenbock.
Yeast Lab W51 Bavarian Weizen
This strain produces a classic German style wheat beer, with moderately high,
spicy phenolic overtones reminiscent of cloves. Medium attenuation, moderately
flocculant. Evidently much more consistent than Wyeast at producing a true
Weizen flavor.
Mead Yeast
Yeast Lab M61 Dry Mead
Very alcohol tolerant, ferments dry, fruity and clean, yet leaves noticeable
honey flavor and aroma.
Yeast Lab M62 Sweet Mead
This strain has reduced alcohol tolerance, therefore produces a very fruity,
sweet mead with tremendous honey aromas.
Wine Yeast
Lallemand Lalvin Wine Yeast S. Bayanus. Good reputation.
Red Star Pasteur Champagne Yeast
Very attenuative. Good for mead. Good reputation. Popular yeast for Imperial
Stouts and Barleywines due to it's high tolerance for alcohol. Some use it by
itself, others pitch Pasteur after their chosen beer yeast poops out.
Wyeast 3021 Prise de mousse Champagne Yeast
Institute Pasteur champagne yeast race bayanus. Crisp and dry, ideal for
sparkling and still red, white and fruit wines. Also can be used for Barley
wines. Optimum fermentation temperature: 58 deg. F (14 deg. C).
Wyeast 3028 Wine Yeast
French wine yeast ideally suited for red and white wines which mature
rapidly. Enhances the fruity characteristics of most wines. Optimum fermentation
temperature: 72 deg. F (22 deg. C).
Wyeast 4007 Wine Yeast
Malo-lactic culture blend isolated from western Oregon wineries. Includes
strains Ey2d and Er1a. Excellent for high acid wines and low pH. Softens wines
by converting harsh malic acid to milder lactic acid. Can be added to juice any
time after the onset of yeast fermentation when sulfur dioxide is less than 15
ppm.
Yeast Culture Kit M06
From Montreal, Canada. VSU: Barley Wine (Champagne).
============================================================================
SECTION III: YEAST MANAGEMENT
PART 1: HYDRATION PROCEDURE FOR DRY YEAST
a. Use 14 grams of dry yeast (usually 2 packets) per 5 gallons of brew.
***Rigorously*** sterilize everything used in the hydration procedure. This
should include boiling and cooling the water for rehydration, so that chlorine
is boiled off and the water is sanitized.
b. Add the dry yeast to 1/2 cup of water at 90F (32C). Leave for 15 mins.
c. Combine the hydrated yeast with 1-2 gallons of wort that is as close to the
wort to be fermented as possible. You can take samples from the main wort at the
end of the mash/sparge and rapidly boil and cool it.
d. Aerate the starter as much as possible under sanitary conditions.
e. Don't forget to properly oxygenate the main wort once it is *chilled*.
(Shaking hot wort is dangerous, but even worse it can cause oxidation and give
your beer funny flavors.)
f. Pitch the starter into the main wort once the latter has been chilled to the
recommended fermentation temperature (65-68F or 18-20C). Yeast with good
viability will result in minimal lags. (The longest experienced in test brews
using the new Red Star Ale Yeast was 2 hrs.)
An alternative but slightly sub-optimal method is to cool the yeast-in-water mix
from "b" to room temperature. Once the wort has been chilled and aerated
(shaking the carboy works well), pitch the yeast. Stir or invert the carboy to
disperse the yeast. Put in the blow-off tube or fermentation lock.
The two most essential things are to:
1. Sanitize everything in sight.
2. Aerate your wort to insure rapid initial yeast growth--your best defense
against secondary infection.
------------------------------
Date: Thu, 26 Aug 1993 16:25:16 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 7 of 8
D. Preparation of New Slants
Two steps are needed in the preparation of new slants. The first consists of
adding the proper media to test tubes or petri dishes. Once prepared the slants
will store well far a very long time when refrigerated, so many can be prepared
at one time. The second step consists of inoculating the slants with yeast.
For the homebrewer who cannot afford several refrigerators: Please be advised
that your refrigerator is a haven for bacteria, mold, and wild yeast. Anyone
wishing to store sterile slants in their refrigerator is advised to
1. Wipe down the slants before storage with ethanol or your favorite
sanitizing solution.
2. Seal the slants with parafilm or electrical tape.
3. Keep the slants in a ziplock bag.
4. Wipe down the bag with ethanol or your favorite sanitizing solution before
opening.
Preparation of Media:
(i) The media consists of dry malt extract and agar. As a general rule 4
tablespoons of malt extract and 1 tablespoon of agar per cup of water will yield
16-18 slants.
(ii) Bring the water to a boil, and then stir in the malt extract. Boil for 10
mins.
(iii) Remove from heat, and then start stirring in the agar. This will take some
effort, but this usually indicates that a good solidification will ultimately be
achieved. If your slants "sweat" too much, increase the amount of agar you use.
Although commercial/scientific agar will vary little, I cannot answer for "food
grade" supplies. Gelatin is easier to dissolve, but it sometimes does not always
give a proper solidification.
(iv) When the agar is dissolved, the malt/agar solution should be added to the
test tubes, filling each to approximately a third of their volume. Add the screw
cap, but do not fully tighten.
(v) Autoclave the tubes at 15 psi for 15-20 mins.
(vi) Allow the tubes to cool. They can be left overnight in the autoclave/
pressure-cooker. Tighten the caps on the tubes, and place them at a 30 degree
angle. Allow them to solidify at room temperature. Solidification should become
apparent within a few hours. Tubes which are not solid after 24 hrs. should be
discarded.
(vii) Refrigerate until needed, heeding storage precautions above.
Note: Plastic petri dishes can not be autoclaved, and so alternate procedures
are needed for them. You may use the above techniques with *pyrex* petri dishes
if you so desire. A common practice is to autoclave the malt/ agar solution in
small jars or flasks. The agar solution is then poured into the petri dishes.
Let the agar cool until the jars are hot but touchable. If the agar is too hot
it will warp the plates. Swirl it gently to mix but avoid bubbles. It is a good
idea to leave petri dishes prepared in this way at 25-30 C for 1-2 weeks to make
sure bacteria or molds are not present. Let the poured plates dry overnight in a
clean quiet room. Wipe them down, seal them, and bag them, but leave them at
room temperature for 1 week. The bad bugs, if they are there, will be visually
apparent at the end of that period and the contaminated plates discarded. While
Petri dishes are more trouble than test tubes, they do offer the distinct
advantage of having more surface area and being easier to store. After the trial
period the dishes should be refrigerated.
Inoculation of Slants:
(i) Collection a small portion of the yeast to be added to the slants. It goes
without saying that one should strictly follow the standard sterilization
procedures of all items used to collect this yeast.
(ii) With one hand sterilize the inoculation loop (flame or alcohol solution).
With the other hand open the cap of a slant.
(iii) Dip the loop into the yeast solution, and remove a small amount.
(iv) Slowly insert the loop into the tube avoiding contact with either the sides
or neck of the tube. Streak the yeast over the solid. Only a thin layer is
wanted, and one should try to use as much of the surface area as possible.
(v) Slowly remove the loop avoiding contact with tube walls or neck. Add the
screw cap back on the tube and tighten.
(vi) When finished store the tubes at 25 C for one week. Visually inspect all
tubes at this time both for yeast growth, and also for any irregularities.
Discard those which are not satisfactory.
(vii) Store the remainder at 2-8 C. After 3-4 mos. of storage, unused tubes
should either be discarded or recultured; i.e., propagated by the procedures in
Section III.2.c and then put on fresh slants. The best idea is to put production
yeast on slants on a regular basis so that reculturing is not necessary.
Note: The larger surface area afforded by Petri dishes can be used to advantage
in the above procedure. In particular, it useful to streak out yeast in parallel
lines which make angles with each other. This allows for a better examination of
growth patterns. Petri dishes should be sealed after the 1 week trial period
with electrician's tape and refrigerated.
------------------------------
Date: Thu, 26 Aug 1993 16:25:36 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 8 of 8
PART 3: YEAST WASHING FOR THE HOMEBREWER
Doug O'Brien forwarded the following to me. As it is a topic that pops up
frequently on the HBD, I have included it in this FAQ.
Post follows:
The following notes were taken from a demonstration given to the Oregon Brew
Crew by Dave Logsdon of WYeast Labs, on September 12th. According to Dave, it
was important for healthy yeast to be washed free of trub and hop residue so
that it could be stored for future use. Dave said that the problem with simply
storing the mixed contents from a carboy after fermentation was that the
unwanted particulates would suffocate the yeast over a period of time.
Most breweries, Dave stressed, use an acid wash; the sterile water wash is
much more practical for homebrewers.
Objective: To recover yeast from a finished batch of beer for repitching or
storage for future brewing.
Materials: One primary fermenter after beer has been siphoned off or
otherwise removed.
Three sanitized 1-quart Mason jars with lids, half full of sterile or boiled
water. They should be cooled down, then chilled to refrigerator
temperature (ca. 38^F).
Procedures:
1) Sanitize the opening of the carboy (flame or wipe with chlorine or
alcohol)
2) Pour the water from one of the quart jars into the carboy. Swirl the
water to agitate the yeast, hop residue and trub from the bottom.
3) Pour contents from the carboy back into the empty jar and replace the
cover.
4) Agitate the jar to allow separation of the components. Continue to
agitate periodically until obvious separation is noticeable.
5) While the viable yeast remains in suspension, pour off this portion into
the second jar. Be careful to leave as much of the hops and trub behind
as possible.
6) Agitate the second container to again get as much separation of yeast
from particulate matter as possible. Allow contents to rest (about 1/2
hour to 1 hour) then pour off any excess water--and floating hop
particles--from the surface.
7) Pour off yeast fraction which suspends above the particulate into the
third container.* Store this container up to 1 month refrigerated. Pour
off liquid and add wort 2 days before brewing or repitch into a new brew
straight away.
*It should be noted that in the actual demonstration, Dave eliminated the
final step; the yeast in the second jar was essentially clean at this stage
and seemingly fine for storage.
- ----------------------------------------------------------------------------
PART 4: PARALLEL YEAST CULTURES
Rick Cavasin sent me (PW) the following method of "parallel" culturing
liquid yeasts. This should work with most packaged liquid yeasts, not just
Wyeast. The advantages here for the beginner are that (in additon to saving
money) it minimizes the problems of strain drift and contamination that can
plague yeast ranchers. As for the savings, it makes liquid yeast almost as cheap
as dry yeast!
Post follows:
Here's the (poor man's) method for stretching the Wyeast that I (Rick) have been
using successfully. This method has worked for me with 4 different Wyeast ale
strains (Whitbread, Irish, German, European). It's simple, and requires no
special equipment. Also, it allows several brewers to swap yeasts with each
brewer propagating one strain.
Briefly, my suggestion consists of converting the original Wyeast package into a
number of 'copies' stored in beer bottles. ie. it is a parallel propagation
rather than a serial propagation
Step 1: Prepare some starter wort (S.G. = 1.020), see Miller's book for recipe.
Basically, you need about 1/2 gallon, but if you make more and can it in mason
jars (using standard canning procedures), you will not have to prepare more at a
later date. Note from PW--Most authorities now recommend using full strength
(1.040), hopped wort for starters.
Step 2: Place 1/2 gallon or so of starter wort in a suitable container (1 gallon
glass jug), pitch (inflated) Wyeast package at correct temp. and fit air lock.
This is the 'master' starter.
Step 3: Allow to ferment to *completion*. When fermentation has ceased, agitate
the 'beer' to suspend all sendiment, and very carefully bottle it.
You will now have about 6 bottles of very thin beer with a good deal of viable
yeast sediment in each bottle. Use each bottle as you would use a package of
Wyeast - ie. prepare a starter culture a couple days before brewing. This is
facilitated by canning wort when you prepare the master starter. All you need
to in that case is pop open a mason jar of wort, dump it into a sanitized
bottle/jug of appropriate size, pop open one of your bottle cultures, add it,
agitate vigorously, and fit an air lock.
All yeast starters are of the same 'generation', ie. 'twice removed' from the
original Wyeast package (as opposed to the usual 'once removed'). I've had the
bottled cultures remain viable for more than 6 months.
Observe proper sanitation and wort aeration procedures thoughout.
Equipment: 1 gallon jug (for 'master' starter)
1.5 litre wine bottle (for subsequent starters)
air lock
6 beer bottles, caps and capper
Optional equipment: mason jars and canning pot.
Cheers,
Rick C.
- ------------------------------------------------------------------------------
------------------------------
Date: Thu, 26 Aug 1993 16:42:23 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 6a of 8
PART 2: PROPAGATION OF YEAST STRAINS
or
HOW TO HAVE YOUR VERY OWN YEAST RANCH!
A. General Comments
There is no single item as important as the selection of a yeast strain, or
if appropriate strains, to be used in commercial brewing. The same applies to
homebrewing. Sensory characteristics -- taste and smell --will normally
determine the type of yeast that is appropriate to any particular beer
formulation. This section contains the necessary procedures for achieving
self-sufficiency in pitching yeast. The part treated in this section is often
called the Hansen pure culture system. The heart of this system is the so-called
"yeast slant". It is a test tube containing a solidified media sloped at an
angle. Often Petri dishes are used, but the media is level, and hence the term
"slant" is not always appropriate. In any case, yeast cells are streaked on the
surface of the solid media. When refrigerated, these slants will keep at least
3-4 months before they have to be recultured. Yeast are taken from the slants,
and built up so there is enough to pitch a full batch. The system also contains
procedures for doing the exact opposite, i.e., adding yeast to slants for
storage and future use.
B. Equipment
The equipment needs for operating a pure culture system with slants are
rather modest. The following are the major items.
1. Refrigerator. This is needed for slant and media storage.
2. Autoclave or pressure cooker. This will be needed to sterilize equipment and
media for yeast work. A pressure cooker will do, but it should have a pressure
gauge attached so that the conditions during sterilization can be controlled.
3. Media. The preferred media for slants is malt extract and agar. These can be
obtained from any scientific outlet. Food grade agar is also available from some
oriental markets. The flaked form is easier to work with.
4. Misc. A number of minor items will also be needed. These include inoculation
loops, glassware, petri dishes, and test tubes.
C. Propagation of Yeast
This process consists of transferring some of the yeast on slants to a small
flask or jar containing wort, then building this up until there is enough to
pitch a full brew. the most delicate steps are the initial ones. Experience has
shown that the best results are obtained by using full strength hopped wort for
propagating yeast. The ideal situation is when the wort used in propagation is
identical to the wort that will be used in brewing.
Practical experience has also shown that it is best to pitch yeast freshly
harvested from slants at the maximum acceptable rate. Anticipating the results
in the next section, this for lager yeast amounts to pitching 1 volume of yeast
*SOLIDS* for each 250 volumes of wort. Thus, we need 5gal/250 =
0.02gal*128oz/gal = 2.5oz of yeast solids for a 5 gallon batch. Using the
estimation that yeast solids are 1/10 the total volume of a yeast culture, that
means that one needs about 25oz or a little more than 3 cups culture. For ale
yeast all of these numbers are reduced by a factor of two, so (3/2) to 2 cups of
an ale yeast culture would be sufficient.
In the procedure described below new wort is added just after the end of the
period of high krauesen, and in particular after the foam starts to recede. The
reason for this is to keep the yeast in the aerobic exponential growth mode.
This will insure a steady buildup of yeast cells, and thereby minimize the
number of wort charges that are required. The importance of taking great care
when adding fresh wort can not be overemphasized. To avoid infections not only
is it necessary to properly sanitize equipment, but it also important to
sterilize necks of vessels and jars by flame or 200 proof alcohol solutions. The
easiest way to flame a jar at home is with a lighter (esp. the ones for pipe-
smokers!). Be extremely careful, and don't use both alcohol and a lighter.
The first four steps described below are done under the cleanest conditions
possible using 1000 ml. starter jars. At the end of step (iv) there will
invariably be more than enough yeast in each starter jar to pitch a 25 liter
brew (about 6gal); i.e., there will be at least 1/10 liter of yeast solids as
can be checked by visual inspection. These numbers are based on the requirements
of lager yeast. As will be seen below there will be no harm in producing too
much yeast in this procedure since at the end only the correct amount will be
added to the fermenter.
------------------------------
Date: Thu, 26 Aug 1993 16:42:43 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 6b of 8
(i) Preparations:
a. Carefully inspect all the slants that are to be propagated. Those which have
unusual growth patterns and/or discoloration should be discarded. The ideal is
thin white yeast layer on top of the solid media.
b. Autoclave the starter jars and the rubber stoppers for the airlocks for 5
mins. at 15 psi. Alternatively, use your favorite chemical sanitizing agent.
c. Add 250 ml. (about 8 oz) of wort to each starter jar. Wipe their necks with a
200 proof alcohol solution. After this add the airlocks.
d. Pasteurize the wort by adding the starter jars to a water bath at 60 C (140
F), and hold this temperature for 20 mins. Cool to 18 C (75 F).
e. In a clean room with no air movement (turn off fans and air conditioning for
at least 15 min to give the dust a chance to settle) and then place starter
jars, yeast slants, inoculation loops, and a 200 proof alcohol solution in a
clean, quiet spot (i.e. lock the door after first insuring that Fido, Fluffy,
and Junior are on the other side of it :-) !).
(ii) Inoculation:
For each jar, start by sterilizing its neck. Then sterilize ("flame") the
inoculation loop. Open a slant, quench the loop in clean agar ("sizzle") and use
the loop to remove some yeast. Remove the airlock and then add the yeast to the
starter jar. Replace the airlock, and then start work on the next jar.
(iii) Initial Buildup:
a. Place the starter jars in a location where 68F (18C can be held). Aerate
twice daily by vigorously shaking jars. 1L Erlenmeyer flasks are excellent for
this purpose because they permit vigorous swirling without getting the wort up
by the neck and opening. Also good are 1.5L ex-wine bottles.
b. A widely used practice is to discard any starter that is not active within 48
hours. Certainly if some of the starters are active within this period, then the
inactive ones should be discarded. In any case, any starter not active within 72
hours should definitely be discarded even if this means they are all discarded.
(iv) Second Wort Charge
a. When the foam has receded prepare 250ml. of fresh sterile and aerated wort
for each starter.
b. The new wort is to be added to each starter, and this should be done as
cleanly as possible.
c. Before pouring the wort into the starters, it is very important to swab the
necks of the starter jar and the wort jar with a 200 proof alcohol solution to
prevent contamination or flame them with a lighter.
d. It is also desirable to reduce the temperature to a point closer to the
temperature that will be used in production if that is lower than 18 C. The
temperature should be reduced *slowly*, e.g. few degrees a day. Large shifts in
temperature (>10 deg F or >5 deg C) can cause marked slowing of yeast growth.
e. The starters should be aerated at the start and then again after 12 hours.
New activity should be seen before 24 hrs. Those which are not active within
36-48 hours should be discarded.
f. Increase the volume of wort until you have sufficient volume to pitch.
(v) Pitching the Yeast
a. At this time you should have a jar with about 500ml (a little more than 2
cups) of yeast for a 5gal ale batch. I would suggest pitching *just after* the
krausen (foam) dies down, the logic being that the yeast have amassed glycogen
reserves and are at their healthiest. Some other sources recommend pitching at
high krausen, reasoning that the yeast are in the exponential growth phase.
Whatever you do, avoid overdilution (greater than 10 fold increase in wort
volume) and keep accurate notes. The total volume will vary with batch size,
yeast type, and your personal experience/whim. Remember to keep yeast notes
along with your beer notes so that you can learn from experience!
b. Clean the outside of the jar with 200 proof alcohol or weak bleach and allow
to dry.
c. Pour the yeast slurry carefully into the primary.
------------------------------
Date: Thu, 26 Aug 1993 17:07:56 -0500 (CDT)
From: WEIX@swmed.edu
Subject: yeast faq 2 of 8
SECTION I: YEAST CHARACTERISTICS
ACTIVITY
Some yeast strains are more active and vigorous than others. Lager strains in
particular do not show as much activity on the surface as many of the ale
strains. Most packages provide an adequate quantity of yeast to complete
fermentation with varying amounts of lag time depending on strain, freshness,
handling, and temperature. If you find it too slow, make a starter as
recommended on the package or as listed in Section III.
TEMPERATURE
The slow onset of visible signs of fermentation can be improved by starting
fermentation at 75 deg. F (24 deg. C) until activity is evident, then moving to
your desired fermentation temperature. A few degrees does make a significant
difference without adversely affecting flavor.
The normal temperatures for ale yeast range from 60-75 deg. F (16-24 deg. C)
A few strains ferment well down to 55 deg. F (13 deg. C). 68 deg. F (20 deg. C)
is a good average. Lager strains normally ferment from 32-75 deg. F (0-24 deg.
C). 50-55 deg. F (10-12 deg. C) is customary for primary fermentation. A slow
steady reduction to the desired temperature for secondary fermentation typically
works well.
The fermentation rate is closely related to temperature. The lower the
temperature, the slower fermentation commences. Fluctuations in temperature such
as cooling and warming from night to day can adversely affect yeast performance.
ATTENUATION
Attenuation refers to the percentage of sugar converted to alcohol. Apparent
attenuation of yeast normally ranges from 67-77%. The attenuation is determined
by the composition of the wort or juice and the yeast strain used. Each yeast
strain ferments different sugars to varying degrees, resulting in higher or
lower final gravities. That will affect the residual sweetness and body.
Really, it's slightly more complex than that (isn't everything ?-).There's
"apparent attenuation" and "real attenuation". The difference comes about
because alcohol has a specific gravity less than 1 (about 0.8). Real attenuation
is the percent of sugars converted to alcohol. So, if you had a 10% (by weight)
sugar solution (about 1.040), and got 100% real attenuation, the resulting
specific gravity would be about 0.991 (corresponding to about 5% alcohol by
weight). The apparent attenuation of this brew would be 122%! George Fix
published a set of equations relating apparent and real attenuation and alcohol
content last year. For example, let
A = alcohol content of finished beer in % by wt and
RE = real extract of finished beer in deg. Plato.
Since A and RE are generally not known to us, additional approximations are
needed. The following are due to Balling, and have proven to be reasonable. Let
OE and be defined as follows:
OE = original extract (measured deg. Plato of wort)
AE = apparent extract (measured deg. Plato of finished beer).
Then,
RE = 0.1808*OE + 0.8192*AE,
and
A = (OE-RE)/(2.0665-0.010665*OE).
The "tricky part" here is the expression of the sugar content in degrees
Plato. This is a fancy term for % sugar by weight, and corresponds *roughly* to
"degrees gravity" divided by 4. That is, a 1.040 wort has an extract of 10
degrees Plato. He goes on to calculate an example: To take a specific case,
first note that from Plato tables an OG of 1.045 is equivalent to OE = 11.25
deg. Plato, while a FG of 1.010 is equivalent to AE = 2.5 deg. Plato.
Therefore,
RE = 0.1808*11.25 + 0.8192*2.5 = 4.08 deg. Plato,
and
A = (11.25 - 4.08)/(2.0665 - .010665*11.25) = 3.68 % wt.
The apparent attenuation is 75% (from 1.040 to 1.010), the real attenuation is
(11.25 - 4.08)/11.25 = 64%. N.B. Most attenuation figures are given in terms of
*apparent* attenuation. (Thanks to Chris Pencis quoting Stuart Thomas quoting
George Fix).
FLOCCULATION
Flocculation refers to the tendency of yeast to clump together and settle out
of suspension. The degree and type of flocculation varies for different yeast.
Some strains clump into very large flocculate. Some flocculate very little
giving a more granular consistency. Most yeast strains clump and flocculate to a
moderate degree. Flocculation simply refers to how well the yeast stick to one
another. A yeast that is more flocculant will fall out of suspension better, but
since it will be in the bottle at least a week before you drink it, it really
doesn't matter so much for clarity. How it does matter is that if the yeast
settle out too quickly, they may leave some chemical reactions unfinished.
Mostly these strains: 1) May not be as attenuative because of shorter contact
time with the sugars, 2) May not finish reducing all the diacetyls, leaving a
butterscotch flavor.
pH RANGES
Typical pH range for yeast fermentations begins at about 5.1 and optimally
4.8. The pH of wort is usually about 5, depending on the starting pH of the
water and the grains or extracts used. During the course of fermentation the pH
reduces to typically 3.9- 4.1 and as low as 3.1 in some wines. pH may be checked
using pH paper test strips, which are available at many homebrew shops.
Typically there is little need to adjust the pH.
ALCOHOL TOLERANCES
The alcohol tolerance for most brewing yeast is as least to 8%. Barley wines
to 12% can be produced by most ale strains. Pitching rates need to be increased
proportionally to higher gravities. Alternately, Champagne and Wine yeast can be
used for high gravities sometimes reaching alcohols to 18%. To get the
characteristics of particular beer yeast strains in Barley Wines or Imperial
Stouts, some brewers start with the desired beer strain, brew to 5-8%, and
finish with a champagne or wine yeast.
SMELLS AND TASTES
Although the principle tastes present in a beer are the result of the malts
and hops used, the strain of yeast used can also add important flavors, good
and/or bad. Yeast that add little in the way of extra flavors are usually
described as having a "clean" taste. These yeast are especially useful for
beginners because they permit experimentation with different ingredients without
worrying about yeast influence. Yeast produce three main classes of metabolic
by-products that affect beer taste: phenols, esters, and diacetyl. Phenols can
give a "spicy" or "clove-like" taste, but can also result in mediciny tastes,
especially if they react with chlorine in the water to make chlorophenols.
Esters can lend a "fruity" taste to beer. Diacetyls can give beer a
"butterscotch" or sometimes a "woody" taste. The desirability of any one of
these components depends largely on the style of beer being brewed. In addition,
there are certain by-products in these families that are more noxious than the
others. A lot depends on the individual palette and the effect you<O~>re aiming
for.
A final note: some yeast, especially lager yeast during lagering, can produce
a "rotten egg" smell. This is the result of hydrogen sulfite production.
Although the scent of this bubbling out of the air-lock is enough to make the
strongest homebrewmeister blanch, fear not! The good news is that this will
usually pass, leaving the beer unaffected. Relax, etc.
OBTAINING CULTURES AND MISCELLANY
Most of the dry strains are available by mail-order or at your local homebrew
store. Wyeast are also widely available (by which I mean, of course, that *my*
local store carries a wide selection). The BrewTek strains and the Yeast Culture
Kit strains are significantly less available, so the company contact numbers are
included as a public service.
BrewTek: (800) 8BRE-WTE
Yeast Culture Kit Company: (800) 742-2110.
------------------------------
Date: Fri, 27 Aug 93 06:03:58 -0700
From: ksegal%spf.dnet@gpo.nsc.com (KEN SEGAL EXT. 8920)
Subject: septic systems and bleach and yeast
In reply to the query on bleach doing in your septic system.
A good rule of thumb is no more than 1gal of bleach/month per 1000gal
septic tank.
As far as yeast goes...yeast eats starches which only amount to 7%-8%
of the solid matter in your tank. Bon apetit.
------------------------------
Date: Fri, 27 Aug 93 08:58:25 -0500
From: zentner@ecn.purdue.edu (Mike Zentner)
Subject: NOEL@????.hp.com
I tried to reply to your message sending you wort chiller plans,
but your address is wrong. Please send me your address again if
you still want the plans.
Mike Zentner
------------------------------
Date: Fri, 27 Aug 1993 10:08:46 -0500 (EDT)
From: Jim Busch <busch@daacdev1.stx.com>
Subject: Whats Weihenstephan??!
IN the last digest, Jack asks, Whats Weihenstephan??
Heres German brewing lesson #101:
Weihenstephan is the oldest continuosly operating brewing center
in the world. It is located north of Munich, in the fabulous
town of Friesing. Weihenstephan has two breweries, a state run
"industrial" brewery that makes some so so beers, and the small
school brewery that is affiliated with the extremely anal and
respected Weihenstephan brewing school/institute. They operate
a yeast bank which is the source for many of the most popular
strains of lager and weizen yeasts (Weih 66, and 34/70 for ex).
A single strain of yeast on a cotton ball (dry!) costs about
$200! Think about that next time you buy the same yeast for
$2-3 from a yeast culture supplier. Weihenstephan is an extermely
respected and difficult school to be accepted into. You must
speak fluent German to enter, and a difficult test (oral &
written) is given. As if this isnt enough, you must be an
experienced brewer to atttend. Often this means you do duty
as a grunt worker in a brewry cleaning tanks to get the
"experience" required. I believe you also need to do this
aprenticeship under a Diplom Braumeister ( a graduate of
Weihenstephan). Usually , Diplom Braumeister's never actually
brew after graduation, they often are employed as heads of the
QC division of Bud or Miller. In germany, they are also fond
of opening hausBraueries (brew pubs). A very anal & difficult
school. Dr. Narziss has been the professor/god for quite some
time and authored excellent papers on things such as rapid
high temperature fermentation anad aging of lager beers,
"the Narziss" method of quick lagering as mentioned by Dr.
Fix in BT issue #2.
BTW, Jack, nice Maltmill! It did get a bit pricy since I
needed the upgraded gear and spacing option, but I now have
it motorized with a 10" pulley on the mill and a 3" pulley
on the motor. After mounting the mill on an extension of my
workbench, I just pop the trash can under the mill, and
start pouring 65 pounds of grain through the thing. Now if
I can just engineer a ceiling mounted grain hopper, I'll be
all set (with auger feed of course :-)!!
Good brewing,
Jim Busch
------------------------------
Date: Fri, 27 Aug 93 07:58:12 PDT
From: tima@wv.MENTORG.COM (Tim Anderson)
Subject: Labels and whining (mine)
The only labelling I have ever done is to write the batch number on the cap
with a felt pen. I use a rather complex numbering algorithm:
Batch # = Previous Batch # plus 1
After much research I settled on "1" for my original batch number, Arabic
numerals and base 10. For example, my latest has "24" written on each
cap, whereas the previous batch had "23". It is important to use the same
number on each bottle in the same batch. For easy reference, I keep a chart
on the wall near where I keep my brewing supplies, with a list of all the
numbers from "1" to "100". At bottling time, I just have to look at the number
on the cap of a bottle from the previous batch, find a number on the chart that
looks the same, and use the next number in the list. By the time I go to
write the number on that first cap, my adrenaline is really pumping.
I'd be happy to provide more details via email.
tim
ps I think the Oregon Brewers Festival has gotten WAY too big. The best
thing about it was that Samuel (tm) Adams (tm) wasn't invited.
------------------------------
Date: Fri, 27 Aug 93 09:57 CDT
From: korz@iepubj.att.com
Subject: Mark at Lotus
Mark-- I lost your email and USmail addresses. Please send again.
Sorry for the use of the bandwidth.
Al.
------------------------------
End of HOMEBREW Digest #1214, 08/30/93
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