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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
  mixed yeast fermentation ("-S")
  Replies on Beer Classification Systems (Alexandre Enkerli)
  re: flocculation ("-S")
  RE: Beer Classification and BJCP Styles ("David Houseman")
  Re: Carbonation Level for Dunkelweizen (Jeff Renner)
  BJCP Guidelines (gornicwm)
  an interesting style (Marc Sedam)
  Dallas Shops (neils)
  Yeast ranching ("Bill Kunka")
  Re: Dunkelweizen Carbonation (Robert Sandefer)
  Oxygenation, flow rate, air stones, saturation ("Rob Dewhirst")
  Widmer yeast (Randy Ricchi)


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Date: Fri, 21 Nov 2003 01:57:10 -0500
From: "-S" <-s at adelphia.net>
Subject: mixed yeast fermentation

Dave Burley notes ...,

<<
"I also hope some lightbulbs will go on in home breweries around the world
that maybe a blend of yeasts will produce better results. It does require a
blend at pitching of primary stable strains of yeasts for each brew or the
results, like yours, will be unpredictable from batch to batch. This will
obviate yeast recycling.
>>

I buy the idea that using several yeasts *could* produce a better tasting
beer, but I think the old practice brewing with mixed yeasts at a brewery
spoke to a lack of sanitation and the English pattern of rejecting pure
culture practices till well after WW2, rather than an intention to make
better beer.   When you consider all the differentiating growth factors that
would naturally impact any two yeasts, it is absolutely impossible that
those old traditional breweries had  a stable ratio of their several yeasts.
I doubt one could even grow stable ratios of two distinct yeast in a modern
lab setting !

This goes to your suggestion that one should pitch a blend of the two yeasts
to get predictable results.   A better method is to separately ferment two
portions of wort and blend the resulting beers to get repeatability.  You
could even blend in the glass if you wish.   You could then reuse the yeast
and experiment with blending ratios and several yeasts easily, as winemakers
do.

 -S




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Date: Fri, 21 Nov 2003 03:28:38 -0500
From: Alexandre Enkerli <aenkerli at indiana.edu>
Subject: Replies on Beer Classification Systems

I won't intervene further on this subject but I did want to express my 
gratitude to everyone who replied to my post on classification systems. 
I'm relieved to see every comment is thoughtful and insightful. These 
comments also bring diverse points of view (with some commonalities) 
and raise several fascinating points (alternate uses for and fringe 
benefits of classification systems, expectations, typological criteria 
and parameters, historicity...).
Drink for thought!

I'm also glad nobody seemed to interpret my post as an attack on the 
BJCP, its members, or even its guidelines. I reiterate my deepest 
respect for all of what the BJCP has brought to our world.

Oh, and for those who might disapprove of the thread, I'm sorry to have 
started it but it has really helped me a lot.

Thanks to all!

Alex (aka Ale-X), in Montreal
[555.1km, 62.8] Apparent Rennerian



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Date: Fri, 21 Nov 2003 04:15:01 -0500
From: "-S" <-s at adelphia.net>
Subject: re: flocculation

Dave Burley writes ...

<<
Oregon Alt wonders why his beers stop fermenting partway through,
but stirring speeds them on.

In a word - flocculation.
>>
and contends that stirring counteracts flocculation.


Flocculation does not cause the end of fermentation, it's a coincident
symptom.  The cause of slow and apparently stopped ('stuck' or 'sticking')
fermentation is that the yeast are not growing.  This is a much simpler and
more direct explanation.  Even yeast which do not flocculate can 'stick' -
and stirring would obviously have no deflocculating effect on these.

Brewing yeast flocculate when the cell surface properties change via at
least two distinct genetic mechanisms.  For brewing yeast these mechanisms
are suppressed whenever growth conditions obtain.  Yes, yeast stop
fermenting (or slow down vastly) when they flocculate, but they only
flocculate because they can no longer grow.

Stirring yeast does not change their cell surface properties, and cause them
to DEflocculate.  Typical stirring cannot even yield separate cells - they
remain flocced.  It's been shown that the deflocculation process involves
restoring growth conditions and then allowing time for the yeast to
synthesize new surface proteins.  That's exactly what happens when you add a
kreusen or priming addition or repitch a flocculated yeast cake.

The correct question is this ....
What causes growth to cease and why does stirring fix it ?

Some common nutrient deficiencies involve  oxygen related lipids, amino
acids and biotin.  Other factors that can impair and even stop growth are
high alcohol concentration,  high CO2 concentrations and low pH.  CO2 and O2
are both affected by stirring, and a mere 40mg of O2 would be a substantial
boost to a 5gal batch.

Yeast enjoy low CO2 levels (around 0.25 atm) as they can use some of the
carbon for biosynthesis.   At 1 atm the CO2 reduces growth by two known
mechanisms (and fermenters often contains 2atm of CO2 at peak fermentation).
CO2 impairs the yeast's ability to create the redox balance (sort of a yeast
acidosis).  That causes an imbalance in the fermentation pathway which ties
up phosphates and also reduced the internal cell pH - which in turn reduces
the activity of one of the enzymes on the pyruvate energy pathway.   High
CO2 levels especially late in the fermentation at lower pH give your yeast
cells a serious hangover !   The cells lose the energy flux necessary to
signal growth conditions and the flocculation mechanism is enabled.  The
cell surfaces change, they clump and drop to the floor in a coma awaiting
more energy.

With hi-alcohol or hi-gravity and low lipid levels the yeast have a
different problem.  The cell membranes, which are meant to be selectively
permeable become too weak and overly-permeable with low lipid levels.
Healthy yeast expend a large fraction of their metabolic energy pumping ions
across cell membranes against the osmotic pressure.  Low lipid yeast cells
expending far more since the ions are leaking back in - low lipid yeast
operate like the bilge pump on a leaky ship.   They also have problems
keeping their internal metabolic operations functioning efficiently because
of this.  Again flocculation follows and autolysis hot on it's heels in this
case.

Somehow stirring alleviates some growth limiting restriction. Stirring
certainly removes CO2 and may add a little O2.  This is the likely
explanation of why stirring works.

<<
One solution, especially in London, [...] or to
move ( "drop")  the entire batch to another fermenter to finish it off..
>>

The practice of dropping is associated with English yeast which have high
oxygen requirements.  There is  little doubt that "dropping" removes CO2 and
adds O2.


As the Monty Python sketch goes ....
<<
This is a late parrot ! It's a stiff! Bereft of life, it rests in peace !
If you hadn't nailed him to the perch he would be pushing up the daisies!
Its metabolic processes are of interest only to historians !  It's hopped
the twig !  It's shuffled off this mortal coil !  It's rung down the curtain
and joined the choir invisible!  This is an Ex-parrot !
>>

OK - flocculated yeast are not dead like Graham Cleese's parrot, but
throwing them up into the wort is every bit as ineffective as nailing a dead
parrot to the perch.  It cannot even separate the flocced cells, much less
reverse the flocculation bioprocess.

Here's the mantra - "growing yeast never flocculate; flocculated yeast never
grow".  Restore growth conditions and both flocculation and attenuation will
take care of themselves.  This applies generally.

 -S




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Date: Fri, 21 Nov 2003 07:57:47 -0500
From: "David Houseman" <david.houseman at verizon.net>
Subject: RE: Beer Classification and BJCP Styles

Robert,

Look at Category 24, Specialty/Experimental/Historical.  This is an open
category.

Dave Houseman



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Date: Fri, 21 Nov 2003 10:04:41 -0500
From: Jeff Renner <jeffrenner at comcast.net>
Subject: Re: Carbonation Level for Dunkelweizen

"Don Scholl" <dws at engineeringdimensions.com> writes from up the 
road at Twin Lake, Michigan:

>I'll be bottling my Dunkelweizen tomorrow and I would like to know a
>carbonation level (volumes CO2) that you use or is specified for it.

One of the very best books in the Classic Beer Style Series is Eric 
Warner's _German Wheat Beer_.  Part of its great appeal to me is that 
his German training resonates with my own German-American anal 
fussiness.

Warner has a lot to say about carbonation, and uses the very useful 
grams CO2/100 ml (per cent CO2 by weight) for carbonation rather than 
volumes CO2, which I find far more intuitive and useful.  The nice 
thing about this is that since one gram of sugar produces very nearly 
0.5 grams of CO2, it is easy to determine how much priming sugar to 
add (don't forget to take into account the dissolved CO2 present 
already in your finished beer).

He writes (p. 39), "Perhaps the most striking quality of Weissbier is 
its high degree ofcarbonation.  German lagers may have a CO2 content 
of 2.3 volumes (0.45 percent by weight), and American lagers may be 
slightly higher, but Weissbiers are even more effervescent.  Levels 
range from 2.8 to 5.1 volumes (0.55 to 1.0 percent by weight). 
Weissbiers at the higher end of the scale tend to bed too gassy, and 
it is easy to become bloated by just one of the.  I prefer beers that 
have a CO2 content of less than 3.6 volumes (o.7 percent by weight), 
but many of the popular Weissbiers in Germany have a level that is 
higher."

He goes on to write (p. 25) that carbonation levels for Dunkles 
Weissbier is similar to that of pale Weizen.

Warner shows a clip-on manometer that is placed on a bottle to 
monitor the pressure build-up during bottle fermentation.  Since you 
probably don't have one of these, let me suggest a simple way of 
monitoring the progress of carbonation that occurred to me a little 
while back - fill a half liter PET soda bottle while you are 
bottling.  You can check carbonation by how hard the bottle becomes. 
Of course, since PET bottles are not oxygen impermeable, you should 
ddrink this beer early.  And, if you have fridge space, keep all the 
beer cold as weizenbier has a poor shelf life.

I sent this suggestion (for all beers, not just Weizen) to Zymurgy, 
where it was published recently.  As editor Ray Daniels commented, it 
is surprising that such a simple idea had not occurred to anyone 
before, or at least that it had not been promulgated within the 
homebrew community.  It seems that it should simply be SOP for all 
bottling, and should be suggested in beginning homebrew books 
(attention John Palmer and Charlie P).

Cheers

Jeff
- -- 
Jeff Renner in Ann Arbor, Michigan USA, JeffRenner at comcast.net
"One never knows, do one?"  Fats Waller, American Musician, 1904-1943


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Date: Fri, 21 Nov 2003 10:28:44 -0500 (GMT-05:00)
From: gornicwm at earthlink.net
Subject: BJCP Guidelines

I'm sure that most brewers out there, especially brewers that brew
competitively, have two types of brewing etiquette - "guideline" brewing 
and "playtime" brewing.

Even if you are "Clone" brewing, you are still using a type of "guideline".  
Your guideline happens to be the physical beer you are after and not the 
description of what the beer should be.

I would argue that its just as rewarding to brew a style that indisputably 
nails the BJCP guidelines as it is to develop a "creative" brew that 
satisfies all of my personal tastes regarding how I think a particular brew 
should taste.  In both instances, skill and care are needed to develop a 
GREAT beer.

I also hope that skill and care was taken to formulate the BJCP Guidelines.  
I would have a hard time believing that IBU, SRM, and gravity requirements 
for the styles were pulled from a hat.  I trust that research was done, in 
this respect.  I am faithful that it was.

I think most brewers in general have a desire to break from the norm, so 
even if a homebrewer is brewing per guideline, the temptation to sway 
from guideline specific brewing always exists...and God bless it!!!

Guidelines "guide" the brewer.  I don't think that BJCP Guidelines were 
ever intended to be the "Rule Book for Homebrewing" and they should not 
be treated as such. They are by no means the be all end all to brewing and,
in my opinion, should not be abused in this way.  Go ahead and argue about
the guidelines because that's what they're there for.  C'mon, what would a 
homebrew club meeting be without a good, old-fashioned bitch session about 
the style guidelines.  ;-)

Give the guidelines a break.  It is impossible to capture all of the 
intangibles that a beer is delivering to a persons senses, but the BJCP 
Guidelines come awfully close.  Beer styles are both historic and evolutionary 
and that is what makes homebrewing so fantastic - it allows us to taste 
the past as well as develop new flavors for the future. 

Bill


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Date: Fri, 21 Nov 2003 13:17:22 -0500
From: Marc Sedam <marc_sedam at unc.edu>
Subject: an interesting style

Someone's posting yesterday reminded me that creativity is a good thing.

I've recently had 2-3 beers that had a grain bill of a stout but were 
fermented with different strains of Belgian yeasts.  All of these 
"Belgian Stouts" (there I go...classifying again) were really 
interesting and refreshing beverages.  If you're in a creative funk, 
give it a try.  I was surprised at how much I enjoyed them.

- -- 

Marc Sedam
Chapel Hill, NC




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Date: Fri, 21 Nov 2003 13:31:09 CST
From: neils at texas.net
Subject: Dallas Shops

I hate to cloud the digest with non-brewing related stuff but I'd like to ask 
any hbd-ers from Dallas a question. Do you know of any shops in the DFW area 
that carry Bert Grants and/or Bridgeport products? Both companies' websites 
have distribution in the Dallas area. Despite the great selection at Central 
Market and Grapevine here in Austin, neither of these folks' products are 
available here and I'll be in the Dallas area over the holidays.

Appreciate any input. Happy Brewing!
Neil Spake
Austin,
Texas



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Date: Fri, 21 Nov 2003 16:40:57 -0500
From: "Bill Kunka" <wkunka at tbaytel.net>
Subject: Yeast ranching

This is my first post to the digest, and I have been brewing for a few
years. This week end I am going to make the jump to all-grain.

My question is, is there a way to store yeast long term? I am planning to
brew a Koelsch and am using the Wyeast Koelsch ale yeast.

Bill


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Date: Fri, 21 Nov 2003 16:17:19 -0500
From: Robert Sandefer <melamor at vzavenue.net>
Subject: Re: Dunkelweizen Carbonation

This year I made two dunkelweizens and primed each with 1 cup corn sugar. 
Therefore, these beers probably had ~2.7 vol CO2.

http://hbd.org/brewery/library/YPrimerMH.html suggests that German wheat 
beers should have 3.3-4.5 vol CO2, but I am not that confidant of my 
bottles.

Plus, my beers were plenty spritzy for my taste.

Robert
Arlington, VA



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Date: Fri, 21 Nov 2003 17:14:33 -0600
From: "Rob Dewhirst" <rob at hairydogbrewery.com>
Subject: Oxygenation, flow rate, air stones, saturation

I recently moved up from the very expensive disposable 1.1 cu ft disposable
02 cylinders to a 20 cu ft 02 tank.  I also have attached to this tank a
medical oxygen flow regulator and a 2 micron airstone.

I understand that about 90 seconds of pure oxygen introduction with a 2
micron stone can saturate wort to about 9-12 ppm, but at what flow rate?
Certainly the flow rate out of the stone makes a difference.

Also, since I cut my oxygen costs by almost exactly a factor of ten, I am
considering oxygenation after pitching, at a continual but much slower flow
rate than at pitch time.  I have read that some commercial breweries do this
for up to 24 hours.  What is a safe oxygenation duration time to start with?
1 hour post pitch or so? at what flow rate?



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Date: Fri, 21 Nov 2003 20:47:19 -0500
From: Randy Ricchi <rricchi at houghton.k12.mi.us>
Subject: Widmer yeast

Does anyone know if Wyeast or White Labs has the Widmer hefe-weizen yeast, 
and if so, what the product number/name is?
TIA
Randy




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