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


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Contents:
  Valhalla, Mead-only competition ("David Houseman")
  Search me! ("Pat Babcock")
  Correction: Valhalla, Mead-only competition ("David Houseman")
  E is for Esters ..../re: Oats in light colored beer. ("-S")
  Freezing vs. Canning wort... ("Michael Eyre")
  flux for soldering copper (Matt)
  re: E is for esoteric ("Chad Stevens")


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JANITORs on duty: Pat Babcock (pbabcock at hbd dot org), Jason Henning,
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Date: Tue, 20 Sep 2005 23:11:50 -0400
From: "David Houseman" <david.houseman at verizon.net>
Subject: Valhalla, Mead-only competition

This is reminder and call for judges for this mead-only competition.  If
you've already contacted me to judge, there's no need to respond again.
But if you haven't and can judge meads, please contact me at my email
below.

If you've got mead, prepare to enter the 1st annual Valhalla - The
Meading of Life Mead-Only Competition to be held Saturday, October 15 at
the Mt. 
Pleasant Cafe, 311 W. Mt. Pleasant Ave, Philadelphia, PA 19119
(http://www.mtpleasantcafe.com/).  This competition will judge meads in
BJCP categories 24--traditional meads, 25--melomel and 26--other mead.
One entry per subcategory per entrant, with a $5 per entry fee. The
equivalent of at least 3 12-ounce bottles is required for judging,
although bottle size and shape are not restricted. No identifying
markings however can appear on the bottles.  Any standard competition
entry form may be used.  It is the responsibility of the entrant to
properly identify the category and sub-category based on the 2004 BJCP
Style Guidelines.

Meads may be mailed or dropped off at Home Sweet Homebrew, 2008 Sansom
Street, Philadelphia, PA 19103 by Friday, October 7th.  Additional local
drop off locations include Keystone Homebrew locations and Iron Hill
Brewery and Restaurant in West Chester, PA.

The competition would like to encourage knowledgeable mead judges to
commit to judging this event.  Judges will receive breakfast and lunch.
Judges should contact David Houseman to secure a judging seat.

The judging will take place from 9am to 1pm. Awards will be given out
beginning at 1:30. There will also be a tasting with numerous commercial
meads as well as the remainder of the meads from the competition
following the judging.  Following the competition there will be 2
seatings for a "Mead-ieval" dinner at 4 and 6:30 pm, reservations
required; call the restaurant at 215-242-1500 to make your reservations.

Suzanne McMurphy, Competition Organizer (theimann at verizon.net) 
David Houseman, Judge Coordinator (david.houseman at verizon.net) 
Vince Galet, Asst. Competition Organizer


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Date: Tue, 20 Sep 2005 23:52:03 -0400
From: "Pat Babcock" <pbabcock at hbd.org>
Subject: Search me!

Greetings, Beerlings! Take me to your lager....

Well, I suppose I have to speak up over all the search mystery on the HBD 
site. Here's where we're at... The search on the HBD domain is based on a 
very old (1995 - ancient, in terms of software!) free text search tool. 
Over the years as the kernel and the C compilers used have evolved, the 
source for this tool is no longer "compilable" unless I reach back to 
skills that were honed razor sharp waaaaaaaayyyyyy back in 1986. And, the 
system no longer functions as intended.

My first approach is to determine what in the security model or directory 
structure has caused the tool to fail, and, if possible, fix the issue. 
This is the process I'm in now. So far, the failures (re: error messages 
on execution)are manifold. Knocking them down one at a time as I find the 
time. This approach will allow me to easily retain the function set and 
scope of the existing search.

This failing, I'll be installing a more modern package. I've been putting 
this off since the modern ones are also slower, being written in languages 
farther from the binary the micro loves to babble.

In any case, we'll get there. Sooner, if not later. Patience, please! In the 
meantime, the google search does a pretty fair job.

- --

See ya!

Pat Babcock in SE Michigan
Chief of HBD Janitorial Services
http://hbd.org
pbabcock at hbd.org


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Date: Wed, 21 Sep 2005 19:40:28 -0400
From: "David Houseman" <david.houseman at verizon.net>
Subject: Correction: Valhalla, Mead-only competition

Sorry, it's only two (2) bottles of precious mead for this competition, not
3.

Dave Houseman



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Date: Thu, 22 Sep 2005 06:15:59 -0400
From: "-S" <-s at adelphia.net>
Subject: E is for Esters ..../re: Oats in light colored beer.

I know Chad Stevens knows better, yet  ....
> The important part to note is that oats have a higher fat/lipid
content[...]
> Fats and Lipids are bad for foam; their derivatives can be major flavor
and
> aroma contributors however.

True *if* these lipids persist into the beer, but they don't.  Yeast can and
will consume many times the lipids that appear in normal wort.  I suspect
that oats (and rye) have more foam-negative glucans and less of the
hydrophobic glycoproteins necessary for great head.

> [..] both fats and lipids are made up of fatty acids and are generally
> not soluble in water but are soluble in acids, alcohol, and bile.

By definitio, "lipid" is the fraction soluble in non-polar organic solvents,
but not in water.  Fatty acids are the aliphatic(- big word for straight
carbon chain) carboxcylic acids.  The mid-length and long FAs are lipids (C6
and longer), but the short ones, like acetic acid(C2.FA) and butanoic(C4)
are water soluble and not lipids.  Fats (di- & tri- acyl-glycerides) are
made from long chain fatty acids, but many many other lipids are NOT made of
fatty acid (sterols, hops oils, terpenes).

> Typically, to make an ester, all you need is an alcohol and a fatty acid.

Not really  - and we've just been over this in excrutiating detail.    If
anyone cares to disprove the statement above, just mix some vinegar (the C2
fatty acid) with ethanol and wait until you smell the resulting
ethyl-acetate ester (nail polish remover aroma).  It will probably take
several centuries since you have forgotten that this is an enzymatically
controlled reaction.

The most important carboxylic acid involved in beer ester formation is
acetic acid, not a lipid, and not derived from grain lipids but from sugars.
The next most important carboxylic acids for esters are butanoic & hexanoic
and these are mostly from yeast building fatty acids, not grain lipids.

The primary ester formation process is rate limited by the alcohol
acyl-transferase (AAT) class of enzymes.   The AAT type, quantity and
activity is dependent on yeast genetics, yeast metabolic conditions and
temperature.

Also adding long chain fatty acids to wort DECREASES the final ester levels
in beer.  There are several reasons: FAs, particularly UFAs may be a growth
limiting factor for yeast;   Long FAs, the most abundant type,  are strongly
inhibitory of the AAT enzyme; yeast may be inhibited from even producing
AATs in the presences of free FAs.

The small FAs produce floral&fruity esters, while long FAs esters are about
as fruity and floral as the deep fat fryer at a MacDonalds.   See
"insecticidal soap", a combination of long FA esters and salts for example.

> The number of possibilities is a function of the number of fatty acids
> available and the number of alcohols available.
*** and rate determined by AAT enzymes, not by substrate.

> All of the even numbered C2
> to C30 common saturated fatty acids are found in nature.  That is 15 fatty
> acids.

As an aside, there small but significant amounts of odd-chain length fatty
acids (C3, C5, C7) in yeast and hops.  These have a very interesting
metabolic origins and fates.    Hops are actually fairly rich in heptanoic
acid(C7) probably as a precursor to it's aromatic oils.

> So 15 fatty acids multiplied by 4 alcohols are 60 ester
> possibilities.

There are probably about 20FAs and even more carboxcylic acids in the
fermenter, but only half a dozen appear in sufficient abundance to cause any
ester aroma (~1ppm for most esters).   The longest FA to regularly finish
above 1ppm is hexanoic often around 2.5ppm.   Only 3 FAs are seriously
implicated in beer esters above aroma threshold, acetic, butanoic, and
hexanoic(C2, C4, C6) [[wtih ethyl-octanoate from octanoic(C8) as a special
case]].   The long chain  lipids just aren't a significant part of the ester
aroma story.

There have also been 40 fusels identified in beer, but the only 6 alcohols
than make the aroma concentration cut are ethanol, n-propanol, iso-butanol,
n-methyl-butanol,  and 2-phenyl-ethyl alcohol maybe 2-methyl-propanol.
Technically glycerol is a very abundant alcohol in beer (up to 1000ppm), but
isn't involved in common ester formation (well fats are really poly-esters
of long FAs and glycerol, but they don't smell like much)   [[Why no small
carboxylic esters of glycerol  in beer ?  I mean butter contains
glycerol-butryrate, not that I'd enjoy buttery beer]].

Anyway 6 FAs * maybe 6 Alcs hit the concentrations to be involved so maybe
there *could* be a universe of 36 beer esters that could ever hit aroma
threshold  Just over 100 esters have been identified in beer, tho' most far
below threshold.

This calculation ignores that  yeast enzymes are selective, and most of
these 36 hypotheically important esters are almost absent because the enzyme
activity isn't there.  For example n-methyl-butanol and n-propanoal are
sufficiently abundant fusels, but common yeast AAT enzymes almost ignore
these alcs.

No the ester list is more like this (for ales)

    ethyl acetate         <=  ethanol + acetic            18 ppm
    ethyl butyrate       <= ethanol + butanoic         0.5 ppm
    ethyl hexanoate    <= ethanol + hexanoic        0.95 ppm
    ethyl octanoate    <= ethanol + octanoic         1.5 ppm(!)

    isobutyl-acetate    <= isobutanol + acetic         40 ppb
    // little other isobutanol contribution.
    // n-propanol seems to play no role in esters !

    isoamyl acetate        <= n-methyl-butanol + acetic    6.3 ppm
    isoamyl buyrate        <= n-methyl-butanol + butanoic    0.5 ppm
    isoamyl hexanotate    <= n-methyl-butanol + hexanoic    0.42 ppm

   2-phenyl-ethyl acetate <= 2-pheyl-ethyl + acetic    1.6 ppm

So there are maybe 8-10 significant esters from yeast.  Note that acetate
esters (from acetic, not lipids)  are typically an order of magnitude higher
in concentration than the related butyrate, hexanoate, and octanoate esters.


 > Anyway,
> more oats, more lipids, more ester possibilities.

That is oversimplified and misdirecting.  More oats->more lipids is true for
wort, but the yeast are happy to consume these fatty snacks leaving less
esters and a low FA beer as a result.

 -S



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Date: Thu, 22 Sep 2005 07:58:28 -0700
From: "Michael Eyre" <meyre at sbcglobal.net>
Subject: Freezing vs. Canning wort...

Hey all,

I've een pondering this canning of wort for starters thing lately... but
I just don't' have access to a canning pot and don't have the incentive
to go try it out right yet. Frankly, I'm a big nervous about it all. I'm
wondering about freezing, however. Other than the fact that you'd have
to unfreeze the frozen wort, re-boil it, then cool it again... plus the
storage space in the freezer aspect, is there any other downside to
freezing wort for starters?

Mike



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Date: Thu, 22 Sep 2005 12:54:58 -0700 (PDT)
From: Matt <baumssl27 at yahoo.com>
Subject: flux for soldering copper

All,

I am looking for information on the best kind of flux to use for
soldering copper to make brewery equipment.  A search of the archives
turns up the suggestion to use water-soluble flux.  My *guess* is that
any excess flux of this type can be simply rinsed away, but I could be
totally wrong about that.

The search also turns up a decade-old post by John Palmer on cleaning
flux residue, in which he details the need to use either a
gasoline-then-detergent cleaning regimen, or at least a detergent
cleaning if you use liquid flux.  He makes no mention of water-soluble
flux in that post.

My question: what flux can I use (with silver plumber's solder) that
will require the minimum amount of cleaning afterwards?

I'd appreciate any help on this.

Matt


		


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Date: Thu, 22 Sep 2005 19:37:46 -0700
From: "Chad Stevens" <zuvaruvi at cox.net>
Subject: re: E is for esoteric

Steven-

Thanks for the clarifications...I'm big into Lambic, Flemish Red, and
primitive fermentations these days so functionally, oats and other lipid
sources (I'm still playing with flax seed) do contribute to the ester
profile when pedio et. al. are involved; lots more enzymes....  But yes, for
the average Joe using Saccharomyces only, you are by and large correct.
However, I've seen some papers which suggest increased FA contributions
*may* survive through to the end product and *may* be expressed as increased
ester profiles.  I have convinced myself through what I've observed in my
own brewing, that this is more the rule than the exception.  Point was, if
I'm making a nice clean ordinary every day APA and want a big head, I
wouldn't add oats.  A little wheat, maybe.  And if you're really daring, for
a five gallon batch, try boiling 2 ounces of whole flax seed in a gallon of
water and adding that to the mash; it'll give you a persistent head like
meringue.

And of course, "Typically, to make an ester, all you need is an alcohol and
a fatty acid...." was a dramatic over simplification.  We were discussing
fermentations after all, so the enzymatic processes were a given.

As always Steve, thanks,

Chad Stevens
QUAFF
San Diego




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