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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
		Digest Janitor: pbabcock at hbd.org


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Contents:
  Beer's Law ("Peter A. Ensminger")
  Re:  Fermenting on trub: hot and cold break ("Ken Anderson")
  Hop Plants too Old? ("Dave and Joan King")
  re: maturation, heat sanitizing, and wheat beer yeast settling ("steve.alexander")
  enzymes/hops degradation. ("steve.alexander")
  Peter E's Questions ("A.J deLange")


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JANITORs on duty: Pat Babcock (pbabcock at hbd dot org), Jason Henning,
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Date: Sat, 09 Sep 2006 01:49:15 -0400
From: "Peter A. Ensminger" <ensmingr at twcny.rr.com>
Subject: Beer's Law

Much interesting discussion of Beer's Law in HBD #5052 ...

Q1) Is this discussion relevant to the color observed by the ordinary
beer drinker?
A1) Not entirely. We are talking about spectrophotometric measurements
of beer that has been filtered and degassed. Filtering and degassing
eliminates light scatter. Light scatter causes a liquid to "disobey"
Beer's Law. Certainly, Beer's Law does not apply to a freshly poured
Hefeweizen, which is highly carbonated and has lots of suspended yeast.

Q2) Why might filtered and degassed beer "disobey" Beer's Law?
A2) Aside from "instrument error" and scattering, there might be several 
reasons: fluorescence or phosphorescence (presumably insignificant in 
beer); concentration-dependent changes in electrostatic interactions of 
pigments (phenolics, Maillard products, etc); concentration-dependent 
changes in the chemical equilibrium of pigments; and maybe some other 
reasons ...

Q3) In beer, is there evidence for concentration-dependent changes in 
electrostatic interactions or the chemical equilibrium of pigments that 
might cause it to "disobey" Beer's Law?
A3) I am not aware of any. Is anyone else? In my former life as a 
photobiololgist, I had lots of experience measuring plant pigments 
(anthocyanins, flavonoids, chlorophylls, carotenoids, etc). We always 
worried about possible scattering and fluorescence/phosphorescence. But 
I do not recall reading about or encountering concentration-dependent 
changes in electrostatic interactions or in the chemical equilibrium of 
these pigments that would cause our measurements to "disobey" Beer's Law.

Given all this, in addition to AJ's Guiness and Oktoberfest data and 
John V's Beamish data, I think the burden falls upon those who claim 
that filtered and degassed beer "disobeys" Beer's Law. I have no great 
desire to get a cuvette that is several feet thick, just so I can test 
Beer's Law for a Bud Light.

Cheers!
Peter A. Ensminger
Syracuse, NY
Apparent Rennerian: [394, 79.9]




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Date: Sat, 9 Sep 2006 09:14:43 -0400
From: "Ken Anderson" <kapna at adelphia.net>
Subject: Re:  Fermenting on trub: hot and cold break

Date: Tue, 29 Aug 2006 09:34:23 -0600
From: "Mike Racette" <mike.racette at hydro-gardens.com>
Subject:

Mike, you posted this on Aug 29th:



<<<Steve A. posted the following the other day in response to the staling
thread and I wanted to discuss this more:

"The break & trub contain oils that can be readily oxidized and can produce
bad flavor by-products.  The trub is nice for yeast growth, but you
want to separate it out early (secondary fermenter) - while the yeast are
still active."

I've never noticed a difference if I rack off of cold break when yeast are
still active or not, but have always used an immersion chiller and left most
cold break behind. Now that I have finally converted an old keg that I've
had sitting around for years to a boil kettle and bought a plate chiller I
will be sending all cold break to fermenter as many people do.

I have always heard that hot break is something you definitely don't want
beneath your beer and so have never experimented with it. However, there has
been quite a bit of discussion elsewhere from experienced brewers that
ferment in boil kettle leaving fermenting beer on top of both hot and cold
break (not sure how long until secondary) with no reported ill effects. Just
wanting to hear the opinions (both scientific references and experiential
results) on this subject, esp. exactly what are the "bad flavor by-products"
of both cold and hot break?

Mike>>>


I've been watching the HBD for responses, but have seen none.  Bummer!

I, for one, ferment in the boil kettle, on the trub (trub being ALL the
stuff).  I have never read his account, but I have heard that Jeff Renner
has been doing this for years.  Please forgive me if I'm mistaken on that.

In any event, I'm very happy with the results and the simplicity of this
method.  Other tasters and I detect no off flavors, aromas, nor do I have
clarity issues.  Of course the nay-saying status quo crowd will chime in
with esoteric claims that it may be good, but it could be better (by using a
conventional fermenter).  I say bah!

I'm able to seal my BK, so I simply cool, pitch, aerate, put the lid on and
away it goes.  No messing around with sanitizing because the boil does that.
Let me add I always use pellet hops, and they seem to be more easily
contained.  They virtually disappear in the resulting yeast cake.

Anyone else doing this successfully?  I'd also like to hear more accounts.

Ken Anderson





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Date: Sat, 9 Sep 2006 11:57:42 -0400
From: "Dave and Joan King" <dking3 at stny.rr.com>
Subject: Hop Plants too Old?

I've been growing hops for about 10 years now, supposedly Cascades and 
Fuggles, which is probably right.

Is there a life cycle, such that they don't do well after so many years? 
Mine did OK this year, about 40 oz. harvested (dried), with probably that 
much wasted, I just didn't get them picked and dried.  The volume is OK, but 
the hop cone size was generally small.  We seemed to have a great year, hot 
and wet here in South Central NY (Endicott, near Binghamton).  The Japanese 
beetles were really bad, which ate a lot of leaves, maybe that was the 
problem.

Thanks,

        Dave King, President of BIER  http://www.thebierclub.com/
          [396.1, 89.1] Apparent Rennerian 




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Date: Sat, 09 Sep 2006 14:17:25 -0400
From: "steve.alexander" <-s at adelphia.net>
Subject: re: maturation, heat sanitizing, and wheat beer yeast settling

Matt asks ...,

<<
1. Do higher alcohols ever "age out" of a beer?  Some folks take it for
granted that fusels will eventually age out, and some (like me) take it
for granted that they won't.  Anyone have something substantial to back
either position up?
>>

No - there are microscopic losses & additions of common fusels by several
mechanisms in stored beer,  but the levels will be unchanged for decades
if not centuries.

<<
2. What about volatile phenols, such as the famous "clove" flavor in
german hefeweizen?  My guess: they don't age out.  I base this guess on
nothing, except that they are similar in structure to higher alcohols.
>>

4VG - the weizen clove flavor -  is unstable and has a half-life measured
in months in stored beer.  It's somewhere far back in the archives but I
posted a figure I ran across once - like 4 months at fridge temps, but that's
a guesstimate.

<<
3. If an object is put in contact with boiling water, how long does it
really take before that object is "sterile" in the sense that nothing
remaining is a threat to beer?  1 second?  15 minutes?  I think I heard
that 10 minutes is necessary to kill thermophilic bacteria, but I have
no reference for that.
>>

There are claims that some spores can survive boiling, so perhaps forever.
I'd bet on the 15 minute figure.  Steam is reportedly more effective than
boiling and probably requires far less time.   One must wonder if the
microwave is effective too.


<<
4. Does chill haze or protien haze interfere with flocculation/settling
of yeast?  If I brew beer with a good bit of wheat in it, will the
yeast settle faster at 70 degrees (where much of the haze material is
dissolved) or at 40 degrees (where the yeast are more apt to flocculate
and settle, but there are now many more little haze particles in
suspension getting in the way of the yeast)?
>>

There are at least 4 recognized genetic mechanisms for yeast flocculation,
and almost certainly other unrecognized mechanism, so there is no certain
answer, BUT there is no reason to think that protein haze impacts the two
major mechanisms common to brewing yeast flocculation.

Now chilling a beer in late fermentation may cause yeast to flocculate
rather than bubble along at a very slow rate, BUT yeast and other particles
will settle more slowly in colder beer.  Flocculation is a yeast genetic
expression; that is some environmental factor like the lack of sufficient
sugars or perhaps a poor energy balance causes yeast cells to express genes
that change the cell surface to produce thready-sticky lectin-like surface
proteins or to expose surface materials capable of being weakly attached to
di-valent ions like calcium and then ... the yeast cells clump together
and drop out.    The "reason" for flocculation is still open for debate;
it's a clear advantage to the brewer or winemaker, but what do the yeast
get out of it ?

So back to the practical - no I wouldn't expect wheat haze to significantly
impact flocculation.   But you shouldn't normally need to resort to chilling
to knock out your yeast.   Fermentations which flocc' poorly are typically
a sign of poor yeast health.  If you underpitch or underoxygenate or if the
gravity is high compared to the amount of yeast pitched or if the wort
nutrients are low - then late in fermentation the yeast have sugars
remaining to ferment, but they lack the conditions to reproduce - so a very
slow plodding fermentation and poor flocculation follow.  If your yeast
run out of sugars while growth is still possible, then they'll typically
drop cleanly and fastest at the higher temp.   If your late fermentation
is slowed by lack of growth conditions, then chilling may stop the ferment
and cause flocculation, but the settling-out will be slightly slower.

 -S




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Date: Sat, 09 Sep 2006 14:34:34 -0400
From: "steve.alexander" <-s at adelphia.net>
Subject: enzymes/hops degradation.

From: "Jason Gross" notes
> Subject: 100% black patent grist
>
> I've never wanted to try a 100% black patent grist, but it looks as though 
> we may soon be able to.  Some of my colleagues are developing barley with 
> heat tolerant enzymes that will survive malting and kilning.
>
> http://www.ars.usda.gov/is/AR/archive/sep06/barley0906.htm
>   
Ahhh - Cynthia Henson at work again.   Her names shows up in the 
archives for
other barley enzyme work.  This looks like a more stable alpha-glucosidase,
stable thru normal kilning, while beta-amylase quantity and kiln 
survival rate is
the critical saccharification factor for 'normal' beer.   With extra 
alpha-gluc' it
would be possible to produce a very highly attenuative wort - as for 
whisk[e]y
or low-carb beer.

I've come to realize that beer inherently has a lot of dextrins, and 
that the body and
mouthfeel of beer is dependent on these dextrins.  I don't think we'd 
want to brew
conventional beers with this barley.

Greg Brewer says,
> Subject: Hops degradation
>   
[...]

> My guess was to take 10% off the pellets, and 20% off the
> whole; any thoughts?
>   
That's the right ballpark.   Although the amount of humulones degraded is
often much higher than this, the breakdown products still provide bitterness
to the finished beer - or so says the literature.

 -S




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Date: Sat, 09 Sep 2006 19:41:15 +0000
From: "A.J deLange" <ajdel at cox.net>
Subject: Peter E's Questions

RE Q1:  Note that the ASBC method for color determination requires that 
a second absorbtion measurement be taken at 700 nm where beer absorbs 
little light. If this measurement isn't less than 0.039 times the 
measurement at 430 nm the beer is deemed turbid and must be centrifuged 
or filtered.

RE Q2: Consider that a liter  measures E9 x E9 x E9 Angstroms on a side 
i.e. has a volume of E27 A^3. If we put 1.6 millimole (E21 particles) of 
some substance into a liter of water that's 1 particle per million cubic 
Angstroms i.e. each box 100 Angstroms on a side contains on average 1 
particle. The average molecule is probaly 10 A or less in size but some 
polymerized things might reach 100 A in length. The wavelength of 430 nm 
light is 4300A. Makes you wonder. But consider a beer with absorbance 1 
in 1 CM (12.5 SRM). A photon would have a 10% chance of making it 
through a path consisting of E7 of these little boxes with a molecule 
each (1 cm path) and the probability that a photon is captured by a 
particular molecule is 9E-8 i.e. very, very small. So while the 
molecules are  not that far apart in a 1.6 mM solution and while the 
wavelength of the light spans quite a few molecules the interraction 
beetween photons and molecules is apparently very rare, and thus would 
occur at sites many molecules removed from one another.  This, one would 
think, would imply in independence and hence support for Beer's law.

One thing that might cause a change in color with dilution would be if 
the beer were acid but weakly buffered so that the dilution caused a 
shift in pH. Lots of things in nature have colors which depend on the 
redox state of the "dyes" which in turn depends on the pH. But we're not 
seeing this either. Also a quickie experiment this afternoon showed that 
adding .1 ml of approximately 13N HCl to 3 ml of beer caused an SRM 
shift from 17.6 to 16.0 (note that adding .1 mL of water would scale SRM 
to 17.0) so pH change, while it does have an effect, doesn't seem to 
have a very large one.

A.J.



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