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HOMEBREW Digest #2088
This file received at Hops.Stanford.EDU 1996/06/30 PDT
Homebrew Digest Monday, 1 July 1996 Number 2088
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Shawn Steele, Digest Janitor
Thanks to Rob Gardner for making the digest happen!
Contents:
Sugar testing ("Ing. John Coppens")
Re: BOUNCE homebrew: unsubscribe looks like an administrative message (kipc@ix.netcom.com (Kip Cooper))
RE: Reusing bottles (Kerry Drake)
re:aeration question/ester tastes/wohlgemuth (awalsh@world.net (Andy Walsh))
Marzen/lager starter (Paul.Lambie@ncal.kaiperm.org)
Wild Hops? (jim.anderson@execnet.com (JIM ANDERSON))
Bittering and Pre-boiled Malt Extract (bobh@instanet.com (Bob H))
German beer purity law? (Mike Foster)
Two Step Chiller (RUSt1d?)
The Coyote is Back! (ccoyote@sunrem.com (John (The Coyote) Wyllie))
Re: esters ("Tracy Aquilla")
Re: ester mystery...part 1 ("Tracy Aquilla")
Re: ester mystery...part 2 ("Tracy Aquilla")
Cooper's Extra Stout (Andrew)
Temperature and Saccharifications - Part 2 ("David R. Burley")
Temperature and saccharification Part 1 ("David R. Burley")
HSA - Chill to 35 F (Edward J. Steinkamp)
taste budsters, chillin' out! (ccoyote@sunrem.com (John (The Coyote) Wyllie))
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----------------------------------------------------------------------
From: "Ing. John Coppens" <jcoppens@linux2.uccor.edu.ar>
Date: Fri, 28 Jun 1996 20:19:18 -0400 (WST)
Subject: Sugar testing
Hi everybody!
The Clinit*st posting gave my pharmacist wife the idea to compensate
for the missing (broken) hydrometer, using a sugar t*st kit to check on
remaining sugar. She brought home a tape called 'Gluco-Cinta' of Lilly
Pharma. I guess this may be called Gluco-Tape or something in the U.S.
Ever distrusting, I dissolved a 1% solution of sugar in water and got
no response at all. Even 2% gave no indication. What's wrong? Does this
t*st give no response to ordinary sugar (probable cane sugar)? According
to the info sheet, the t*st should respond to 0.05%...
The test's composition is:
Aspergillus Niger 3.78 units
Peroxidase de Rabano fuerte 2.82 units of PZ
(Rabano is some kind of vegetable)
o-tolidina 0.14 mg
Buffer 0.007 mg
Non-reactive ingredients 0.48 mg
TIA for any comments,
John.
PS: Is this thing about the '*' in t*st really necessary?
------------------------------
From: kipc@ix.netcom.com (Kip Cooper)
Date: Fri, 28 Jun 1996 19:35:16 -0700
Subject: Re: BOUNCE homebrew: unsubscribe looks like an administrative message
Please CANCEL subscription upon receipt of this mail. This is my third
request.
thank you for your immediate attention..
------------------------------
From: Kerry Drake <drakes@oklahoma.net>
Date: Fri, 28 Jun 1996 23:13:14 -0500
Subject: RE: Reusing bottles
>(I sterilize my bottles by rinsing with
>a bleach solution and then baking them, if this makes
>any difference.) I'd appreciate any advice.
I reuse Sam Adams, Corona (yes, they're clear, but my storage area is very
dark) and even Guiness bottles. I've never had one burst and don't count
the number of times I use them. I'm sure some have been through 20 or more
of my batches! I don't bake them, just put them through the dishwasher
(isn't used for any thing else) with some bleach (never any sanitation
problems). I've heard some have problems after baking, but, others say it's
fine if you cool them slowly enough.
Kerry Drake
------------------------------
From: awalsh@world.net (Andy Walsh)
Date: Sat, 29 Jun 1996 14:37:41 +1000 (EST)
Subject: re:aeration question/ester tastes/wohlgemuth
Bryan asks:
>Also, what advantage is aerating if I have (presumably) "enough"
>yeast to pitch?
>
I'm not going to touch the ester issue, as it appears rash to make such
predictions. The Weihenstephan (lager) summary I most recently quoted from
is interesting as they do organoleptic tests apart from just measuring
chemical concentrations. The most favoured beers were:
- - pitched with the optimal amount of yeast at 1.5e7 cells/ml
(interestingly, 1/2 optimal scored better than double optimal. The latter
was too yeasty. "Optimal" was *about* 0.5l viscous yeast per hectolitre, or
about 100ml per 20l (5US gal)).
- - fermented at 9C rather than 11C or 13C (pils style)
- - aerated with the yeast present to 9ppm.
This is lager rather than ale. The unaerated batch (to 1ppm) scored poorly
in taste tests, although the beer aerated 24 hours after pitching was deemed
reasonable. It would appear that even if you have enough yeast to pitch,
that aerating with the yeast present will still give the best flavoured
beer. It is dangerous to generalise just from one study, but I don't think
that this is terribly radical, after all.
A constant anaerobic environment has a negative effect on yeast fermentation
performance, especially if such yeast is repitched in subsequent batches.
It would appear that if you don't pitch with sufficient yeast, additional
post pitching aeration may be a good thing as it promotes additional yeast
growth, aiding fermentation.
*********
Al and Tracy comment on ester taste.
(Al says you cannot taste esters. Tracy says you cannot distinguish taste
from smell).
My initial reaction was to think that you could certainly taste esters, but
as I just happened to have vials of ethyl acetate and isoamyl acetate in my
freezer, I decided to try it out (FWIW).
I carbon filtered some water into glasses. Sydney water is very soft and
very neutral. To one I added ethyl acetate, another isoamyl acetate and the
other nothing. I did not measure them, but the amounts were MAJOR, and very
obvious from the smell which was which. Holding my nose, I tasted each of
them. To my surprise, they all tasted the same to me.
However, nobody goes around holding their noses when they drink beer (unless
it's FOST-XXXX), so read into this what you will.
*********
Dave Burley attempts to solve the Wohlgemuth riddle:
>P.S. In this same vein and in response to the question "What does "wohlgemuth"
>mean, anyway?", I had to go to an old dictionary (how did they read that stuff
>printed in that old typeface- and a foreign language besides?) [New
>German-English Dictionary ( 1936), Funk and Wagnall's p. 733] which says that
>"wohlgemut" (minus the haitch) means "completely joyous or completely gay". I
>guess you take your choice. Which is it, Andy?
>
AHA! The closet door has been opened!
Yet another explanation for this term has been put forth.
The history of this is that some guy from Iceland posted to me asking me
what a Wohlgemuth unit was. I have no idea why he asked me in the first
place, but I could find no information about it anywhere. It appears to be a
measure of amylase activity units?! But given a lump of amylase, how many
Wohlgemuths are there per kg?
Australians remember the phrase, "Wohlgemuth in the mash tun", so they know
to put their malted barley in the mash, rather than getting them confused
with the hops in the boil. Until I was told this secret, I made really
terrible beer.
Andy.
*************************************************************
Wohlgemuth Walsh from Sydney
email: awalsh@world.net (or awalsh@crl.com.au if you prefer)
I *am* from here. Wanna make sumthin of it?
*************************************************************
------------------------------
From: Paul.Lambie@ncal.kaiperm.org
Date: Fri, 28 Jun 1996 21:52 -0700 (PDT)
Subject: Marzen/lager starter
I'm planning to brew a Marzen for my next project and would appreciate
any recipes (all grain) and suggestions for Wyeast yeast to use. I
plan to make a 4 liter starter - what temperature would be recommended
for fermentation of the starter culture?
Thanks
Paul Lambie
------------------------------
From: jim.anderson@execnet.com (JIM ANDERSON)
Date: Sat, 29 Jun 96 08:44:00 -0500
Subject: Wild Hops?
Has anyone here ever experimented with wild hops? (Or heard of anyone
who has?) I have heard these referred to as "humulus americanus," but
don't know if that's an accurate moniker or not.
In any event, I have access to a virtually unlimited quantity of these,
but I'm reluctant to put my other ingredients to risk, although I might
consider 1- or 2-gallon batches.
I'd appreciate any and all comments, especially with reference to any
associated health considerations. General posting would be fine (others
may be interested), but email's good too. If email, I prefer
"jim_anderson@email.state.ut.us" to the address posted here. Thanks!
- Jim
------------------------------
From: bobh@instanet.com (Bob H)
Date: Sat, 29 Jun 1996 12:02:07 -0700
Subject: Bittering and Pre-boiled Malt Extract
I recently purchased a can of Alexanders Pale Malt Extract that said it was
"pre-boiled". I boiled it anyway to add my bittering hops(Hallertau
pellets). Did I really need to boil the bittering hops into the malt, or
could I have just boiled the hops separately and then added the hop tea to
the malt in my primary fermenter?
Also, the brew came out great but wound up being dark instead of light,
which was ok, but I really wanted it light. Was this a result of
"over-boiling" the extract?
===================================================
Bob Holden, E.A.W.F Software/Computer Tuners BBS
InterNet: bobh@instanet.com .OR. www.instanet.com/~bobh
BBS: (818)887-3258 14.4Kb-300b 8,N,1
===================================================
------------------------------
From: Mike Foster <mfoster1@voyager.net>
Date: Sun, 30 Jun 1996 07:10:00 -0400 (EDT)
Subject: German beer purity law?
I was just thinking about beer again yesterday (a common occurence since I
started brewing)...
Now correct me if I'm wrong, but the German beer purity law states that
beers may only contain 4 ingredients: Water, yeast, malt, and hops.
Now if my memory is correct on that, then what did/do german breweries use
to prime their beers? More malt? Would priming with malt extract work? Would
it change the flavor of the beer?
- -Mike Foster mfoster1@voyager.net
Lord Wulfgar Silberbar proto-incipient Shire of Altenberg
#88 goalie for the SPC Flyers
Jessica Benson Virtual Adept extrordinaire
What? Me? Schizophrenic? Am not!
------------------------------
From: RUSt1d? <rust1d@swamp.li.com>
Date: Sun, 30 Jun 1996 10:34:00 -0400
Subject: Two Step Chiller
The results of my 2 stage chill were pleasing. I use a 30' 3/8" copper coil
in a 5 gallon bucket with garden hose attachments (a cheap-o version of
the coil in PVC pipe kind they sell in homebrew mags). This brings the
wort to about 80F in the summer with the garden hose wide open and uses
lots of water. In an effect to reduce the amount of water used, I used a
mini-chiller on the cooled wort. I made a coil out of 10' of 1/4" copper
and stuck this in a cooler full of ice. The wort ran through this on its
way into the fermentor. I was able to reduce the garden hose flow to a
trickle and have the wort come out at 60F. It took about 45 gallons of water
to cool 13 gallons of wort instead of about 100. All for the price of a
bag of ice (and the coil).
Looking foward to the BUZZ-off competition today at Victory Brewing Company.
I plan on taking first for my porter.
Brewing tip: Use only real leather gloves when touching hot kettles. The fake
ones will melt to your fingers if the surface is too hot. Ouch!
John Varady
Boneyard Brewing
**************************
** rust1d@li.com **
** John Nicholas Varady ** <-- Now Engaged.
** Eve Courtney Hoyt **
**************************
http://www.netaxs.com/people/vectorsys/index.html
------------------------------
From: ccoyote@sunrem.com (John (The Coyote) Wyllie)
Date: Sun, 30 Jun 1996 09:15:25 -0600
Subject: The Coyote is Back!
Greetings brewers one and all. Dropping a line back on the HBD to let
ya'll know I've returned to cyberspace. Some of you might remember me from
about a yeat ago, or so. I live in Northern Utah and brew behind the Zion
Curtain. I'm a grain-brewer, kegger, mead maker, and avid hop grower. I'll
be dropping some posts about my precious hops in the near future. I won't
waste a lot of bandwidth now, so torches off johny. Glad to see some of
the same "faces" are still out there.
Just another FYI, we have an official brewclub now,
Northern Utah! Militia of Brewers.
Perhaps I'll be announcing a club Web page in the future, maybe even an
online newsletter. Send me an e-mail if you have questions, or just wanna
say Hi!
Keep on Hopping! The Coyote Lives!
- --------------------------------------------
/// The Cosmic Coyote \\\ ccoyote@sunrem.com
- --------------------------------------------
------------------------------
From: "Tracy Aquilla" <aquilla@salus.med.uvm.edu>
Date: Sun, 30 Jun 96 13:58:32 CDT
Subject: Re: esters
In Digest #2080:
Andy Walsh <awalsh@crl.com.au> wrote:
>Tracy writes:
>>It's extremely fruity (apple and orange hints), noticeably alcoholic, and
>>bitter, but I don't detect much diacetyl or ethyl acetate. Since I
>>dry-hopped with about 4 oz. of EKGs (in 5 gallons), there is also a massive
>>hop presence which may be masking the other flavors and aromas.
>
>and Al Replies:
>>Whoa!!! 4 ounces of EKG and you can still smell esters? That's some
>>sniffer you've got there... actually, I don't think that any human can
>>identify esters with that kind of hop aroma. Did you judge the fruity
>>aromas before you added the dryhops? Otherwise, I can't believe that
>>you really smell any esters at all there. Sorry...
>
>This got me thinking. What is hop aroma? I checked Hough (V2 pp450-453)
>and discovered that about 30% of the smell of hops is due to esters!
[snip]
Do you guys really think I'm that dopey? Before I dry-hopped in the keg, I
actually drank several pints (about a gallon worth) over the span of a week.
The beer smells like apples and oranges. I think it's from the yeast.
Although I usually use this strain (Wyeast 1968) for my ales, this time I
aerated for several hours and roused daily, as was suggested to me by a
friend who's the microbiologist at a local microbrewery which uses the
Ringwood strain (not Greg Noonan). The one experiment I can suggest is, just
TRY IT! Of course, after adding the dry-hops, the beer is far more complex,
but the apple aroma (ethyl-hexanoate) is so intense it even comes through
the super hop nose. I don't know if ethyl-hexanoate is present in EKG hops
(maybe?), but I know it's a by-product of yeast metabolism.
Tracy
------------------------------
From: "Tracy Aquilla" <aquilla@salus.med.uvm.edu>
Date: Sun, 30 Jun 96 14:17:59 CDT
Subject: Re: ester mystery...part 1
(This message bounced on the first try, so I split it into two)
In Digest #2080:
Andy Walsh <awalsh@crl.com.au> wrote:
>David R. Burley writes
>>There seems to be two diametrically opposed opinions, sometimes put forth by
>>the same person. More oxygen will give more, or sometimes, less esters?
>>I'm confused.
>
>As should everyone else be. There *are* two opposite opinions.
Since one of my posts apparently started this thread, I assume "the same
person" in question might be me, and I'd like to set the record straight. My
opinion is that it really depends on the yeast strain more than anything
else, although pitching rate is also significant, at least with some
strains. 'More' and 'less' oxygen are loose terms and aren't very useful. I
believe with some strains, under-pitching combined with over-aeration can
produce lots of esters (eg. Wyeast 1968, Ringwood, some other Brit. ale
strains), while over-pitching and under-aeration will produce a cleaner
product. This has been demonstrated empirically at Scottish and Newcastle,
the Vermont Pub and Brewery, and Magic Hat Brewery (also in Vermont). In the
case of the latter two, high levels of fruity esters are actually what is
being sought by the brewers. I have also proven this to myself at home.
Other strains MAY also produce more esters if under-pitched and over-aerated
(eg.lager strains, but I'm not really sure about this yet), even though
aeration to 'normal' levels (i.e. 8ppm O2) is generally necessary to produce
a clean product free of undesirable esters. (Hopefully, terms like
under-pitching and over-aeration aren't too ambiguous to get my point.)
>It has been suggested that they may be formed in
>S. Cerevisiae (ale yeast) by a biochemical pathway involving alcohols, fatty
>acids and co-enzyme A (CoASH).
That makes sense, but this pathway(s) has not been completely worked out.
Currently, the molecular basis of ester synthase regulation and the
physiological significance of esters is unknown, mainly due to the lack of
screening methods for the identification of mutants with a modified
phenotype in ester synthesis.
>If a wort contains several individual activated acids and alcohols,
competitive
>inhibition could take place. ie. some esters could be formed in preference
>to others.
In the absence of kinetic data, this is speculative. However, based on
kinetic data presented in the EJBC paper cited below, larger substrate pools
are able to shift the equilibrium to the right, yielding higher ester levels.
>The hydrolysis of acetate esters by esterase is much slower than for
>other esters such as ethyl octanoate. This could help explain why acetate
>esters are so abundant in beer in proportion to other types.
This greatly depends on the specific activities of the particular esterases
and ester synthases in question, which of course is genetically determined,
for the most part. At least four different ester synthase enzymes have been
isolated and purified from S. cerevisiae, each having different catalytic
properties, including ethyl-acetate synthase, iso-amyl-acetate synthase, and
ethyl-hexanoate synthase. All of them are able to catalyze the formation of
several different esters, but each has a different affinity for specific
substrates. Some ester synthases clearly have a stronger affinity for short
and medium-chain aliphatic acids, while other isoforms have a stronger
affinity for longer chains. The same is likely true for esterases. The main
reason acetate esters are more abundant in beer is most likely that
acetyl-CoA is far more abundant than any other acyl-CoA, just as
ethyl-acetate is the most abundant ester in beer because ethanol is the most
abundant alcohol. (Most of this info can be found in Eur J Bchm 210:1015-1022.)
>(the following paragraph is conjecture)
>Some of the
>higher esters (formed from fusel alcohols) have fruity traits which *are*
>desirable in many ale styles. If we could arrive at a wort composition that
>inhibited synthesis of the first two by aiding synthesis of the higher
>esters, we might be on the right track (for ales anyway).
Note that here's a critical point; some esters are more desirable than
others. This could be effectively accomplished in part through the
manipulation of the concentration of specific amino acids and fatty acids in
the wort, but this isn't likely to become common commercial practice for
obvious reasons.
>(back to conventional wisdom)
>As acetyl CoA is clearly related to the level of acetate esters, any factors
>which increase the intracellular pool of acetyl CoA will elevate ester
>production provided that a pool of (fusel) alcohols exist.
This is also a most critical point; very rapid yeast growth leads to an
increased substrate pool. Not only is the concentration of acetyl-CoA
increased, but pools of the other substrates (both acids and alcohols) are
increased as well. Interestingly, exponential growth is also known to induce
multiple esterases in S. cerevisiae (Eur J Bchm 210:1015-1022).
>Acetyl CoA plays
>a key role in cell growth (amino acid/lipid/fatty acid biosynthesis/ TCA
>cycle), hence any restriction of cell growth will elevate acetate esters, by
>increasing the availability of acetyl CoA for ester synthesis. ie. a
>deficiency of oxygen will lead to slower cell growth (O2 is required for
>sterol/fatty acid biosynthesis) and hence greater availability of acetyl CoA
>for ester biosynthesis.
Now we're really getting somewhere. Apparently, either logarithmic growth or
a sudden reduction in growth rate can potentially lead to larger substrate
pools and hence increased ester biosynthesis, assuming the necessary
synthetic enzymes are active. I don't dispute any of the facts you've
reported here, but I think my point is becoming more clear now. At least
some of the ester synthases are induced by logarithmic growth. This is one
reason why ester levels are generally increased with increasing fermentation
temperatures and increasing wort gravity; faster growth yields more substrate.
(end part 1)
------------------------------
From: "Tracy Aquilla" <aquilla@salus.med.uvm.edu>
Date: Sun, 30 Jun 96 14:18:12 CDT
Subject: Re: ester mystery...part 2
In Digest #2080:
Andy Walsh <awalsh@crl.com.au> wrote:
>This is not just theory, and is confirmed by results from many different
>experiments, all of which show greater ester levels with decreased wort
>oxygenation. For example(3):
> 8ppm oxygenated wort 4ppm low O2 wort
>total esters (mg/l) 24.2 34.6
[snip table]
Before you get the idea that my goal is to shred your excellent report here,
I want to emphasize that I basically agree with you so far, and I'm actually
trying to complement your post rather than refute what you've written. I see
8 ppm as being a 'normal' level of oxygen and 4 ppm as being under-aerated
(or under-oxygenated). BUT, what happens if we over-aerate? Have you seen
any data describing what happens to ester levels if wort O2 is increased to
15 or even 30 ppm? You know what I'd predict! Also, the pitching rate cited
is fairly high (i.e. slightly over-pitched). Over-pitching tends to result
in less yeast growth, hence less ester biosynthesis. Finally, I don't really
think of ethyl-acetate when I think of esters, I think of the other
compounds like iso-amyl-acetate and ethyl-hexanoate. When speaking of
esters, it probably makes sense to try to be specific, since all esters
aren't created equal.
>Notice the trends in sterol levels (in particular) and esters. These figures
>just refer to original DO levels. Controlled oxygenation during fermentation
>can lead to even more striking results(2).
I'm interested in seeing similar data on over-aerated worts. If you find
anything please send it my way.
>It has been shown(2) to be particularly important in high gravity brewing.
>ie. the higher the gravity, the lower the O2 levels, the greater the esters.
>Therefore, as high gravity brewing is used extensively in commercial
>operations (to be diluted post-fermentation), controlled aeration is also
>used as a matter of course to bring ester levels down to an acceptable
>value. This is one reason there has been so much professional research on
>this topic (ie. it means money!).
Perhaps the precise definition of "controlled aeration" is the key issue
here. The technical director of Scottish and Newcastle, Dr. David Brown
reports that they routinely do high gravity fermentation of their ales, and
must keep O2 levels relatively low (i.e. minimal, controlled aeration), or
they get too much ester synthesis. Several quotes to this effect may be
found in Noonan's book on Scotch Ales. Their ale strain is a highly
attenuative traditional ale yeast selected in the 1970s from a mixed culture
that had been in use for over 100 years.
>YEAST STRAIN: Each yeast produces its own ester profile, and some strains
>produce considerably more than others.
This is the most important factor, IMO. Since esters don't form in the
absence of synthetic enzymes, and the genes which encode these enzymes are
particular to the yeast strain, the choice of yeast strain probably has the
largest effect on ester levels in beer.
>unsaturated fatty acids, linoleic (C18:2) and linolenic (C18:3) acids cannot
>be synthesized by yeast and are derived largely from trub(3).
I believe this is incorrect. Yeast can synthesize these FAs, but oxygen is
required for their synthesis. This is the main reason for wort aeration;
oxygen is usually the limiting factor for yeast growth in a brewery
fermentation, precisely because unsaturated FAs and sterols cannot be
synthesized by yeast without O2 (J Biol Chem 253:337).
>WORT AERATION: results in increased yeast growth since O2 is essential in
>the biosynthesis of sterols and unsaturated fatty acids. Increased yeast
>growth results in additional demand for acetyl CoA for that purpose,
>resulting again in lower ester synthesis. Even a low rate of aeration during
>fermentation can strongly inhibit ester formation(1,2,3,4,5,6).
While an an increase in growth rate results in an increased demand for
acetyl-CoA, it also results in an increased supply. If yeast is to grow
exponentially, the supply of acetyl-CoA MUST continually exceed the demand,
otherwise accelerated growth would not be possible. Rapid growth yields a
larger pool of acetyl-CoA. I've already discussed the effect of over and
under-aeration on yeast growth.
>OPEN FERMENTATION:As David Burley comments, open fermentations aid DO
>levels. They have been shown to also decrease ester levels (see aeration) (4).
This is counter to what I've read, and my personal experience with open
fermentation. Open ferments generally yield more esters.
>PITCHING RATE: When pitching rate is increased by a factor of 4, ester
>synthesis is reduced.
Agreed.
>Thus control of esters
>is best performed within the first day or two of pitching.
Agreed also.
>(back to conjecture)
>********* WHAT DOES IT ALL MEAN ****************
>Tracy has practical experience indicating what appears to be the opposite of
>what I have summarised above (ie. Tracy says yeast growth leads to greater
>ester production). The general scientific brewing texts do not support this
>(please somebody tell me if they find anything to the contrary!). He quotes
>Greg Noonan (whom we all know and respect) and also Dr. David Brown of
>Scottish and Newcastle in support.
>It appears to me that most all of the research
>has been directed at smaller acetate esters (the most predominant), and ale
>yeasts, and is most likely correct in its measurements and theories
This may be part of the problem. The 'other' esters are far more interesting!
>Higher fusel levels may also form different ester
>profiles! (the most common ester, ethyl acetate, is formed from ordinary old
>ethanol and acetic acid). Hence aerated fermentations could still lead to an
>overall big reduction in ester levels (ie. much lower ethyl acetate and
>iso-amyl acetate levels) but higher levels of other esters that then become
>more obvious in the flavour profile(6). This could help explain the
>empirical evidence as reported by Tracy.
I agree with this too. Fusel alcohol levels are also highly dependent on the
yeast strain.
>In the meantime, we're homebrewers, not science labs, so go try
>a few things and taste the results! This is why I'm interested in hearing
>results from individuals.
Me too!
Tracy
------------------------------
From: Andrew <adkligerman@worldnet.att.net>
Date: Sun, 30 Jun 1996 19:47:50 GMT
Subject: Cooper's Extra Stout
Last week at a good Mexican restaurant I had a bootle of Cooper's EXtra
Stout from that large island just north of the SOuth Pole. I was quite
impressed and
I was wondering if anyone had a good recipe for a good all grain clone of this.
Also, if anyone has some info on the brewery or beer itself I would be
interested.
TIA,
Andy from Hillsborough, NC
"just South of the North Pole"
------------------------------
From: "David R. Burley" <103164.3202@CompuServe.COM>
Date: 30 Jun 96 19:37:52 EDT
Subject: Temperature and Saccharifications - Part 2
DIa!?ayyyyyRyyyyyyyyyyND than as pure extracts (possibly because they are
complexed with the starch and sugars? DRB). I know of no data (does anyone have
it?) that indicates what the stability of beta amylase is in concentrated
maltose solutions? We do know that the starch reaction is slower, how about the
denaturization? Intuitively, I would guess the enzyme would not be fully
extended in high sugar concentration just like it is not fully extended in high
enzymes concentration solutions (This latter info from Tracy Aquilla) and
therefore more stable. ( comments?)
On that subject, I published data that I had extracted from M&BS showing that
the various German and American commercial processes had saccharification steps
lasting from one and a half to three hours. A mention was made,also, that in
the case of well modified British malts, saccharification could last from
fifteen minutes to two hours, without any supporting data and no information on
how long it took to reach 150F. In this latter case, we can't really judge how
much saccharification took place at a lower temperature.
George De Piro said recently "you can rest at 158 until hell freezes over and
your wort won't be very fermentable because not only are you above the beta-a's
optimum temperature (George, see above reason in Part 1 for optimum temperature
- - DRB), but you're also denaturing it."( beta-A is getting denatured at all
temperatures in the range we operate, just faster at higher temperatures and
slower in malt, and perhaps in sugar solutions, than in pure dilute solutions.
- - DRB).
In my own case, I recently prepared an infusion mashed lager in which my
sacharification step took place for 11/2 hours at 159-157 after all the lower
temperature protein rests, etc.. Because I use the dilute-with-boiling-water
technique to get most of the temperature rise, this brew did not spend much
time at any lower temperature in the "saccharification" range, 149-158F.
Temperature adjustment of two or three degrees takes about 3-4 minutes of
direct heating with much stirring.
The Results:
OG = 1.060 @ 60F for 5.5 gallons and FG = 1.015 @ 60F. Nothing untoward
happened, and I got a nice malty,hoppy beer. Not the gooey, sticky tasting
mixture one might conclude from the comments here about the fast disappearance
of the beta amylase leading to high dextrin levels. My efficiency was 89%
extraction, based on Pap's numbers in above ref with the OG of 1.060 for 10
pounds of 6- row american malt plus 12 oz cooked barley in 5.5 gals.
(10*35 + 0.75*30)/5.5 = 67.7 so 67.7/60 = 88.6%
Approximate alcohol = (1.060 - 1.015)* 105 = 4.7% w/w = 4.7*1.25 = 5.9% v/v
from C. Papazian, New Complete Joy of Homebrewing, Avon p.47
This OG is a little suspect because my son (first time brewing) added cooled,
boiled water to the cooled wort, to bring to 5.5 gals, didn't stir and I took
the sample. We later discovered the potential error. The actual OG could have
been a little higher than I measured, if the water stayed on top from where I
sampled. I typically get extractions in the 90s, with consistent results.
My point is, I guess, "long" saccharifications at the high end of the
recommended temperature range do not produce poorly balanced beers and do give
good extraction efficiencies. Brewers who are currently using short
saccharifications, especially at the high T end, can improve their efficiency
and reduce the chance of a starch haze by holding longer. And, because the beta
amylase concentration (and therefore the apparent rate of reaction) is lower at
these higher temperatures, it takes longer for it to chew up the products of
the alpha amylase to produce the maximum amount of fermentables at this
temperature.
If you are willing to wait weeks before drinking beers that you make, why not
hold a few minutes longer at the saccharification step to get consistent, high
efficiency extractions. What's your hurry?
- ------------------------
Tracy Aquilla states that the premise that the tongue can only taste sweet,
salty, sour & bitter has been disproved long ago. I have never seen this. Do
you have a reference?
- ------------------------
Michael HeerBrandt comments on the Ancient Egyptian style beer from Scottish &
Newcastle. There was an excellent show on TV (Ancient Mysteries, I think) a few
months ago in which they showed the whole process, from the evaluation of the
contents of the ancient beer jars, growing of the grain, to production at S&N
lab facility to sampling. Very interesting. I didn't realize how good the
program was going to be or I would have taped it. Does anybody have any more
info on where or when this was shown? Will it be shown again?
- ------------------------
Joe Labeck asks about wormwood flavoring. I only know of wormwood being used in
making vermouth ( say verm ( i.e. worm in German) ut (oot - wood)).
- ------------------------
Steve Alexander's request for a discussion on the effect of fermentation of
various sugars and glucose polymers on taste of the final product is seconded
here, I'd like to know more about this subject also, with some
references,please.
Keep on brewin'
Dave Burley
prove that all of the beta-amylase is gone by this time.
End of PART 1, PARTyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
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From: "David R. Burley" <103164.3202@CompuServe.COM>
Date: 30 Jun 96 19:37:48 EDT
Subject: Temperature and saccharification Part 1
DIa!?ayyyyyRyyyyyyyyyyNDto 10,000 bytes, I guess.
I guess my past comments on this subject weren't read carefully in some cases
or I am writing too compactly. Let's try this subject again, hopefully for the
last time.
We'll agree ( I think) that alpha and beta amylases have different OPTIMUM
temperatures based on two factors, 1) their influence on the rate constant of
the various steps they are responsible for and 2) their different rates of
denaturization. Both of these factors have a positive temperature relationship
and are different for alpha and beta amylase. That is, the rate of catalysis by
the enzyme of the reaction in question increases with temperature and the rate
of disappearance increases with temperature. This results in a somewhat bell
shaped curve of observed overall rate of reaction versus temperature. For the
external observer, that is us brewers, these reactions produce the observed
optimum OVERALL rates for the saccharification of the starch. HOWEVER, this
does not mean that these optimum temperatures are the only temperatures at
which these reactions take place.
I recently posted (I think it got printed in the HBD- If not, let me know and
I'll re-publish it) an extraction of data from the Malting & Brewing Science
which shows, that in the case of decoction mashing, saccharification begins to
take place at 100F! BECAUSE THE STARCH HAS BEEN GELATINIZED IN THE DECOCTION
AND BOILING STEP OF THE MASH. Likewise, in the case of adjuncts, in which the
starch in the adjunct has been cooked to gelatinization, the saccharification
step begins at a low temperature (also, 100F if my memory serves).
So, this addresses a portion of the question from Gregory King about rests in
the range of 140F, while gelatinization of the barley starch does not take
place until 149F is reached. In the case of infusion mashes with
pre-gelatinized starches. e.g. flaked corn, flaked rice,flaked barley and
cooked adjuncts like corn, rice and barley,etc., these can be saccharified by
the amylases at very low temperatures like 100F. Resting at a temperature just
below the gelatinization temperature allows the enzymes to be focussed on the
pre-existing gelatinized starches, I suppose. Gregory, do you have any hard
evidence that a rest at 140F improves the extraction efficiency?
For the case of non pre-gelatinized starches, I have to believe that
saccharification will take place eventually, even below gelatinization
temperatures, since the barley seedling using the same enzymes, is able to do
it at or below room temperature as it grows and utilizes the starch in the
barley kernel. This rate at very low temperatures is not commercially ( nor I
guess amateurly (?)) interesting.
This does bring something to mind, however, that I have wanted to explore. I
understand that the gelatinized starch IN SOLUTION will have fairly normal
kinetics, but I do not know ( and in fact doubt ) the normality of the kinetics
for starch still in the malt grain. We are comparing solution kinetics with a
solution/solid inteface kinetics. This latter case will definitely be surface
area dependent (why else would we crush the malt?) amylase and starch
concentration in the grain will be much higher than in solution, i'll bet, and
inhibiting products will also. Is this the reason the enzymes are more stable?
Any comments?
On more than one occasaion, I have read warnings and disparaging remarks about
the iodine test being useless because if one got grains in the test sample they
turned purple. Sounds to me like the grains still had starch in them, even
though the gelatinized starch in the solution was completely converted. Could
this be the origin of the 15 minute saccharification step?, i.e. improperly
applied starch test causing one to conclude the saccharification step was
complete, simply because the starch ,IN SOLUION, had been converted? As I
recall,perhaps incorrectly, in Charlie Pap's first book (I gave my copy away)
he made some of these disparaging remarks about the iodine test, but then
recovers in his "The Homebrewer's Companion"(1994) Avon Books, NY,NY p.126, by
saying "An additional test can be pursued by removing a teaspoon of grains and
squeezing the liquid out. Testing this liquid indicates how much of the soluble
starches has been brought out of the grain into solution and converted. Large,
poorly ground chunks of malt will take longer for extraction and conversion."
Although, I don't completely agree with the implied (at least to me)
characterization that the reaction only takes place in solution outside the
grain, he is basically correct. Think about how long a good sparging step takes
to remove most of the (very soluble) sugar from the grain - answer an hour or
longer- and you will appreciate one of the major controlling rate factors in
the saccharification step.
In summary, commercial brewers know that it takes longer than 15 minutes to get
COMPLETE, EFFICIENT saccharification of the malt and that is why they take so
long at this stage. Forget fifteen minute saccharifications if you want any
kind of efficiency and reproducibility in your brewing. The fact that some
people recommend them does NOT prove that all of the beta-amylase is gone by
this time.
End of PART 1, PART 2 continues with this discussion.
Keep on brewin'
Dave Burley
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From: Edward J. Steinkamp <ejs0742@dop.fse.ca.boeing.com>
Date: Sun, 30 Jun 96 18:31:18 PDT
Subject: HSA - Chill to 35 F
In HBD#2087, Tom Castle talks of HSA and an immersion chiller.
He says, "... After the boil, I chill down ... to 35F or so.
I chilled my Dusseldorf Style alt bier down to about 45 F, pretty
much the same way. I just stomped the garden hose down into the
snow and then hooked it up to my immersion chiller. I then
underpitched the 10 gal batch with about a quart of Wyeast german
ale yeast. The yeast was shocked into complete submission, never
to be heard from again. I was so bummed. It was my first
decoction batch, and everything was going pretty smooth until the
yeast died.
Does anyone know the maximum temperature differential yeast can
take? I've heard the Wyeast strains like to be pitched at around
70 F no matter what strain. Is this true?
In addition, I did a two-step decoction mash starting at 127 F
protein rest, then stepping up to 154 F rest, and then a 168 F
mash-out. What is the purpose of the mash-out? I think most all-grainers
use a single step infusion process, and thus, never get to a
mash-out temp. How does the mash-out affect the beer?
Ed Steinkamp
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From: ccoyote@sunrem.com (John (The Coyote) Wyllie)
Date: Sun, 30 Jun 1996 21:51:27 -0600
Subject: taste budsters, chillin' out!
In Digest #2086:
korz@pubs.ih.lucent.com Al K. wrote:
>You cannot taste esters. Bottom line.
Tracy Aquilla" <aquilla@salus.med.uvm.edu> cam back in HBD 2087 to say:
>I believe the idea that the tongue can only detect sweet, salty, sour, and
bitter is very old and has been disproved...
Ever try the classic, put on a blindfold, smell an orange, bite an apple.
Taste, ... (drumroll please....) orange of course.
I recall an experiment in high school chemistry where we took a substance
which smelled distinctly like vomit, performed a chemical reaction and
produced a substance which smelled like bananas. Its all a matter of
esters.
The toungue may have its own sensations, but the olfactory system has a
much larger range, and interacts intimately with the taste senses as Tracy
pointed out.
Hey Al, I see you got your biochem references. Esters can be found there,
along with more Michaelis kinetics than you'd care to sink you teeth into.
***
On another topic, the double cooler/ wort chiller;
I once had a setup where I placed an ice water bucket, with spigot on top
of my fridge, ran cold water through an immersion copper chiller placed in
hot wort. Then the wort was siphoned through another copper coil placed in
another ice bucket on its way to a carboy. Things got way chilly mister,
or mistress, or whatever....
Funny I saw a whole article on that exact conceptual subject in BT just an
issue ago. Somewhere back in the archives of eons ago you might even find
my posts from when I was doing it.
I got lazy and now just use an immersion chiller with cold tap water, and
water the plants in the process.
***
Identifying hops:
That's a tough task. Dammit Jim, just brew!
There are some methods of distinguishing hop plants from one another. The
leaf morphologies, and bractioles of the hops themselves (pick a hop, then
pluck off all the "petals" and you have it) can be indicative of the
variety. Doing an alpha analysis and essential oil analysis would also
help narrow the choices. But to truly identify a variety you'd probably
have to turn to DNA analysis. So get your pocket book ready! You mighta
thought alpha acid analysis was expensive! I don't even know how well
mapped the known hop varieties are.
Bottom line IMHO, found a wild hop have you? Enjoy it for just that, a
marvelous plant, of great ornamental value, and if it makes cones that
smell good when squished, and taste bitter to you, then, brew with it!
Guess its gotta be middle of the road alpha level, and plan accordingly.
Part of the reason I went to lengths to separate the different varieties of
hops I have growing (7, if you're counting) is the difficulty in
identifying them.
You might try contacting Steiners. I once got a nice hardcover booklet on
American Hops. "Hopsteiner Guide to American Hops" . Some nice pictures
and variety information. Plus its multilingual! So if you want to practice
your spanish or german, you're on your way! I don't see their address in
the book so good luck to ya. Got a CD Rom phonebook at a local library?
(BTW it was free).
Be aware: There is a "japanese hop" variety that is grown for purely
ornamental purposes. I do not know if it even produces cones, but if so I
doubt they would be much good for brewing. Something to ask about.
- --------------------------------------------
/// The Cosmic Coyote \\\ ccoyote@sunrem.com
- --------------------------------------------
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End of Homebrew Digest #2088
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