---

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


***************************************************************
       THIS YEAR'S HOME BREW DIGEST BROUGHT TO YOU BY: 

                  Beer, Beer, and More Beer
      Visit http://morebeer.com to show your appreciation!

    Support those who support you! Visit our sponsor's site!
********** Also visit http://hbd.org/hbdsponsors.html *********


Contents:
  Crocs and Beer ("Graham L Sanders")
  Fortnight Of Yeast, 2004 ("Graham L Sanders")
  Attempt#2 Explianing idea on "Energy balance" / sugar residuals ("Fredrik")
  Samuel Smith Winter Welcome Clone (Paul Kerchefske)
  Pump Orientation / Industrial Specs ("Reif and Angie Hammond")
  Re: Up and down... (pump mounting) (Kent Fletcher)
  Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals ("Dave Burley")
  Coffee and Beer as Hobbies (Alexandre Enkerli)
  modelling yeast fermentation/sugar utilization (ALAN K MEEKER)
  link of the week - beer festivals (Bob Devine)
  re. electric kettle ("zuvaruvi")
  Rejection. I HATE rejection... ("Pat Babcock")
  Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals ("Fredrik")
  BONES Bash 2004 Competition (Bruce Millington)
  Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals ("-S")
  Competition Announcement: Franco-Belgian Challenge (Eric Schoville)
  Re: Electric Brewery ("Paul Clarke")


* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*           The HBD Logo Store is now open!             *
*            http://www.hbd.org/store.html              *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*  Suppport this service: http://hbd.org/donate.shtml   *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*   Beer is our obsession and we're late for therapy!   *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*               A Fortnight Of Yeast                    *
*  Presented by the HBD in cooperation with Lallemand   *
*      Questions submission: 10/11 - 10/22/2004         *
* include Fortnight Of Yeast, 2004 in your subject line *
* More info http://hbd.org/hbd/archive/4620.html#4620-3 *
*********************************************************
Send articles for __publication_only__ to post@hbd.org

If your e-mail account is being deleted, please unsubscribe first!!

To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word
  "subscribe" or "unsubscribe" to request@hbd.org FROM THE E-MAIL
  ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!**
IF YOU HAVE SPAM-PROOFED your e-mail address, you cannot subscribe to
  the digest as we cannot reach you. We will not correct your address
  for the automation - that's your job.

HAVING TROUBLE posting, subscribing or unsusubscribing? See the HBD FAQ at
http://hbd.org.

LOOKING TO BUY OR SELL USED EQUIPMENT? Please do not post about it here. Go
instead to http://homebrewfleamarket.com and post a free ad there.

The HBD is a copyrighted document. The compilation is copyright 
  HBD.ORG. Individual postings are copyright by their authors. ASK 
  before reproducing and you'll rarely have trouble. Digest content 
  cannot be reproduced by any means for sale or profit.

More information is available by sending the word "info" to 
req@hbd.org or read the HBD FAQ at http://hbd.org.

JANITORs on duty: Pat Babcock (pbabcock at hbd dot org), Jason Henning,
                  and Spencer Thomas



----------------------------------------------------------------------


Date: Sat, 16 Oct 2004 12:33:28 +1000
From: "Graham L Sanders" <craftbrewer at bigpond.com>
Subject: Crocs and Beer

G'Day All

Well one is busy on a number of front. A certain bloody bus is still causing
me grief, as I continue to keep in business half the doctors in
NQLD with regular visits. I have half a mind just to tell the buggers to
"rip it open, cut and hack and see what happens". After all, if I been
bayonetted by these caring soles, they may as well go the whole hog.

On the beer front the Qld Brewing competition is in full swing. The last
round of judging is this weekend. Now we up North are rather a radical lot
(or basically cant be told anything - cant really decide), but I did cause
quite a bit of discussion in Austalia with how we judge beers. Seems people
are split whether consensus judging is the way to go, or stick to the "Three
Blind Mice" principle. That for those who dont know, consensus judging is
where we have a judging panel, (sometimes getting to 9 people), but only one
score and all the judges discuss the beer.

The other massive debate is our practice of warming beers to lift hidden
flavours (good and bad) that may be hidden behind big bold beers.  Boy
aren't there polar opinions on this. Is it OK that a brewer is hiding an
obvious brewing fault behind a big cascade dominated beer. Does it
matter?????. In a classic example, we had a ripper English Pale Ale, scoring
near perfect scores. And it would have won. But on warming it let off a
distinct chessy aroma, that was not evident at serving temperatures. To me a
minor fault, that had to be marked down.

Now lets see. Rob has caught my eye. >>>>>From: "Rob Moline".....Fortnight
of Yeast, 2004
   10.11.04 - 10.22.04<<<<<<< Now mate you are going to have to realise that
while the dear ol USA may think its the centre of the universe, its
certainly not the centre of world standards. I almost missed this.
Why!!!!!!! Well to most of us 10.11.04 is the 10th of November 2004. And
generally I quickly skim over digests. Thank god I re-read it. Mind you you
were good at also spelling out the dates in English, (or was that in
USA-lish ). Now If we can get you lot speaking the same language as us,
writing the same as us (I can talk I cant even spell), and using Metric, you
might not stand out from the crowd.

Ken Pendergrass asks>>> how can a decoction mash be done in a cooler
mash/lauter tun, if it can be done. I confess decoction has me
confused.<<<<<<  Welcome Ken to the GLS Beer Confesional. "My Son", the
problem is easy, all you need is a small pot, and a stove. Look at this nice
easy article, with pickies, that explains it all.

http://oz.craftbrewer.org/Library/Methods/Sanders/GSDecoct.shtml

Now those who want to listen to the only regular beer program in the world
worth listening to should know the latest is up. Go to the following
address. Nothing awe inspiring about this one, appart from listening to mad
NQLDers talking gibberish about all things beer. What am I saying!!!!!!
Those mad bottlers need this to get thru a bottling exercise. Get a keg
people.

http://oz.craftbrewer.org/Library/index.shtml#Sound

From: "Fredrik" >>>>I think it would be unnatural for the equilibrium
residuals to be zero. I mean, who of us licks the plate after a meal?<<<<<<
Now I hate to tell you this, I do!!!!!!!!, even in the fancy corners of the
world. Cant take me anywhere.

And finally as Dave and Alan chew over what is a yeast cell, Is it a hunter,
Is it alive!!!!!. OK Is it a bag of enzymes, or does it think. While both
have good point in the analogy stakes, I have to fall on Alan side. Yes
cells are basically a "Bag of enzymes". In fact a cell is basically a
factory designed for chemical reactions. Because some of these reactions,
and the chemicals used, work more efficently in protected from the outside
world, they are enclosed in a membrane like a soap bubble. (in fact the
anology is closer than you think). In fact the first cells didn't have a
cell wall at all, they were a mass of loose DNA floating arround. A cell
walls just made their energy usage more efficent, the "bag of enzymes", more
stable.

The problem of course with enclosing anything is moving stuff thru the wall,
and regulating it. If a cell is lucky, some just can come straight in, like
simple sugars, with no energy. Great for the yeast, it acts like a mop. But
others need effort, work. This is where the yeast has to make stuff to get
at it, like proteins. But the key here the Engines that produce our
proteins, and enzymes for these reactions (the DNA and RNA strands) dont
just get produced willy nilly, in a vein hope there's something to "latch
onto". Cells aren't that dumb - in a way.

Generally there are a host of chemical triggers that will trigger the cell
to produce a specific protein, amino whatever, and these triggers can either
switch on or off processed. Evolution has set in place a host of triggers
for each specific cell the world over, to meet it needs. So in a way the
cell may not "Hunt" or think about what its doing, but it reacts to the
environment arround it. In the anolgy stakes, like a temperature sensor on a
airconditioner.

I with you Alan, when conditions are right, ie relevant energy usage, then
certain processes kick in, but only when triggers are set off. No point
making enzymes or proeins if they aren't needed. Cells know that.-
genetically. Sugars are taken up sequentually, depending on concentration
levels of the various sugars, and the triggers that sets off the genome.

Now what those triggers are - thats the debate - focus people.

Shout
Graham Sanders


Oh

Although we dont have a croc season, (the buggers take you all year round),
activity certainly takes off when it warms in the tropics. So it was that a
small 4.2 metre youngster slid 100 meters to camp site, into a tent, and
started to drag a decent sized bloke back to the water. Now the difference
between locals and tourists is the tourist would be well rotted by now.

But not us local, in true outback spirit, a 60 plus grandmother jumped on
its back in true crocodile dundee style and started belting the saltie. True
story, as she was head to say "SHITTTTTT< THIS IS A BIG BASTARD". Well it
decide she was meal size and grabbed her instead.  Might be the last of it
til a bloke came by and put a few bullets to the head (of the croc.)

And what did she want after all this, broken bones all over the place. "A
STIFF DRINK".

Got to love her. 



Return to table of contents


Date: Sat, 16 Oct 2004 12:34:40 +1000
From: "Graham L Sanders" <craftbrewer at bigpond.com>
Subject: Fortnight Of Yeast, 2004

G'Day All

I have asked this in a round about way before, but I'll ask again.

With my agricultural background, one thing we learnt was always addressing
the "most limiting nutrient", when looking at the maximum growth or
productivity of whatever your endeavours.

This gets me onto yeast growth and brewing performance.  I have seen in the
past that you fellows hate generalisations, but lets assume we have a
typical 1.050 wort. And our starters are of the same level. We oxygenate
these so that oxygen is not a limiting nutrient, at least in the growth
stage of the yeast. And we are pitching recommended levels. In other words
we are good brewers that do everything right.

Now a typical wort while supplying good nutrition for yeast, does not supply
optimum levels of nutrition. There is room to feed the yeast, to increase
its mass, as well as better its brewing performance. No better example of
this is zinc. Additions of a few ppm of zinc makes a noticeable increase in
the performance of the yeast. In fact more and more brewers add zinc in some
form. So from my agricultural background (here comes the generalisation).
For my typical  oxygenated 1.050 wort.

1. Is zinc the most limiting nutrient in a typical wort.
2. if not what is, and what levels are in the wort, and what levels need to
be aimed for.


But I have more. I like many brewers add zinc, and this has shown a marked
improvement in growth and performance. Its no longer the limiting nutrient.
I have to wonder if there is now another nutrient that could be addressed.
In the unfamiliar world of generalisation, I know you will say it will
depend on the water. Let assume we have Pilsen type water, very soft. We are
good brewers and do get our Ca levels up to 50ppm, with CaCl or CaCO3 in the
mash. We might even add a touch of Epson salts, to get our Mg levels up
another 2 ppm to be safe.  And we practice all correct brewing processes, ie
pH adjustment.

So
1. what would be the next most limiting nutrient a brewer should consider in
his wort. You may wish to split this into growth nutrient and brewing
performance nutrient.  Can you give say give the next two nutrients.

2. And what levels are in a typical wort, and what should we aim for.


Thanks
Shout
Graham Sanders




Return to table of contents


Date: Sat, 16 Oct 2004 08:16:14 +0200
From: "Fredrik" <carlsbergerensis at hotmail.com>
Subject: Attempt#2 Explianing idea on "Energy balance" / sugar residuals

More crazy talk.

I tried to illustrate an idea with my comment to 
Fred's original attenuation thread. Judging from 
the comments it think I unfortunately failed to 
bring forward the idea I wanted comments on, 
The comments focued on misunderstandings with 
"serial/parallell" which was not the core issue. 
I think Dave was a bit confused with my energy 
talk wich was the point I wanted to make, so 
here is another attempt to illustrate what I mean 
with the "energy model" and how treating the yeast
as and organism will help understand how things 
are controlled.

The question was: 

Why doesn't the yeast finish all sugars that is has
the principal capability to deal with?

"Because the kinetic constants have certain values
at certain times" is not the answer I am happy with.

So here goes...

About "Kinetics".

Ok, let say the maltotriose is transported into
the cell slower than any other sugar, but what does 
that have to do with the halt? Why doesn't the cell 
just keep fermenting at a slower rate? This alone
is no explanation, right?

This is where I suggest the energy comes in.

(Analogies, beware)

A Yest cell can be thought of like plant. The task of 
this plant is to produce more plants. A plant needs 
building materials and energy supply to cover for the
energy requirements of construction, administration
and maintainance. If the energy supply doesn't cover
the "costs" the production in the plant will stop. If there
are som parts missing, the production will also halt! 
Even if the production rate is low, you still have 
fairly high costs of administration and maintenance. 
Therefore it is unfavorable to keep the an expensive 
plant running when the production is low. It is better 
to close it down and let the workers go home and call
them back when productions is higher to reduce 
the cost of administration and maintenance. This is 
why many industral plants run 24/7 or maybe 24/6 to
allow for maintenance on day 7. It is not 
economically feasible to build an expensive plant and
run it on 10% of production capacity.

(Need I say, please don't take this litteraly, so leave 
out the comments as to who is the cell manager :)

The accounting has to balance in a cell as in any
plant. Carbon flow, nitrogen flow, energy flow must
balance. Lacking *any of these things* would halt 
the plant production. 

Now to the question what stops the yeast to finish 
the last sugar? 

Lack of nutritients? carbon? This can be the case 
sometimes, but it doesn't seem to be a logic 
explanation in the common case of residual sugars.
There is still enough nutritions in wort, and there is
sugar. Except the sugar is left outside, why? How 
about the crazy idea that there isn't enough energy 
to run the pumps? The transportes are on strike
because they don't get payed.

Some low attenuating strains leave quite 
*alot of sugar*, even though there is also plenty 
of nutritients left. The most sensible explanation 
I can see here at the moment (that I now suggest) 
is that the thing that drags the cell to halt is limited 
energy supply rather than something else. 

This is an idea, that may be wrong, and comments 
are appreciated because maybe I missed 
something important, I am no biologist. I am just 
a modeller.

So the question was. If the energy suppply slows,
why doesn't the cell just keep working, though 
slower?

As the production rate slows, the maintenance 
costs will probably not slow down proportionally,
this decreasing the effiency of the plant! At some
point the manager of the plant will find out that
they are not making money, in fact they are loosing
money but keeping up maintenance, and they will 
decide to shut it down immediately, send home the 
workers. Loosing money here would mean the cell 
loosing health by starting to energy reserves like 
glycogen. 

Lets consider roughly what energy expenses/costs(C) 
and energy feed(E) we have in a cell

COSTS.

As for the energy supply, sugar uses carbohydrates
energy source. These are refined into g-6-p or f-6-p
and are then plugged into the glycolysis and 
fermentation, yielding ATP (an energy carrier).
 
C1 = Transporting energy source/sugar into the cell
C2 = Refining the raw energy source/sugar into the 
         prime fuel g-6-p.

C3 = Maintenance, biosynthesis to cover for cell damage

C4 = Transporting the process waste products out of 
          the cell 

C5 = Productions costs of *new* biomass

FEED.

E1 = (Free) Energy generation (ATP) from g-6-p.

The main task of the cell is to produce biomass.

Lets now consider the energy left for the main task of the 
plant. 

C5 = E1 - C1 - C2 - C3 - C4

Clearly C5 > 0, or the cell will shutdown.

It needs some building materials (carbon, nitrogen, 
oxygen etc)

To produce a given quantity of the product the yeast 
needs a certain quantity of building materials, and a 
certain amount of energy.

I can't see any other logic explanation that it's limiting 
ATP production that causes the residual sugars. This 
is my point and suggestion, and what I mean with 
energy model. Sorry for my lousy skills of explaining.

I have no evidence for this, is just seems like a pretty 
likely explanation? 

If one now considers how stress and sugar composition 
modulates the energy production I find things alot easier to 
understand, and moreover there is a clear logic to it. 

C1 = Transporting energy source/sugar into the cell
C2 = Refining the raw energy source/sugar into g-6-p 
         which is the entry point into glycolysis.

These cost are clearly way higher for maltose and 
maltotriose than for the simpler sugars, and of course 
highest for maltotriose.

C3 = Maintenance, biosynthesis to cover for cell damage

I could just guess that this is related to the environmental 
stress, like alcohol levels etc, maybe various shocks. 
The damaged or old cells that can't be repaired dies.

C4 = Transporting the process waste products out of the 
         cell 

For example, cost of transporting waste out of the cell 
might be expected to relate to gradients, and level of
waste outside the cell. 

This would all suggest that it's the total stress that is 
relevant. ie. if you reduce the cost of maintenance and 
cost of transport by reducing stress factors, CO2, 
gradients etc, the maltotriose depletion should increase. 

I read a report that some strains that basically leaves 
most maltotriose in an anaerobic fermetation, gladly 
respires in maltotriose to full depletion. I think this 
may support the idea to, as aerobic respiration 
prouduces alot more energy than does fermentation.

So my suggestion is that (not always) but maybe more 
often than not, the reason for residual sugars beeing left 
may be an unbalance energy account. The reason that 
the yeast doesn't just keep going slower in stead of 
stopping, is that the maintenace and administration  
accounts does not drop as fast as production. 

The idea is to use these things to construct a mathematical 
regulation mode that I can use in the simulation, to mimic
yeast responses. i,e how to regulate the kinetics. Of 
course the kinetic constants are there, and they have a 
certain value at any time, so we need to make something 
up as howto model the regulation. And yeast beeing an 
organism I think there is an idea behind it. An idea that
seem like a good idea to try to mimic and implement.

Btw. bout paraalell / serial, I think that is finished now,
and I also think I understand how Dave thinks, and the 
confusion seem to be mainly matters of ways of putting 
things, but to see how this fits in here is very clear. As 
any plant, a cell wants to maximize it's production. And 
if there is a sugar that is cheaper to transport and refine, 
that will be prefered until the supply is limiting. Anything 
else would not make any senese, and would have 
the plant manager beeing fired just like such a crazy 
cell would probably not have maintained those ideas
throughout evolution.

 /Fredrik



Return to table of contents


Date: Sat, 16 Oct 2004 06:31:47 -0700 (PDT)
From: Paul Kerchefske <wadworth6 at yahoo.com>
Subject: Samuel Smith Winter Welcome Clone

If anyone has tried to brew a clone of this beer and
had good results could you pass on the recipe. I have
found some info. on it but could use a little more
input. Also what style of beer does this fall under,
it doesn't seem to fit any style very well. Paul


	
		


Return to table of contents


Date: Sat, 16 Oct 2004 09:51:56 -0400
From: "Reif and Angie Hammond" <arhammond at comcast.net>
Subject: Pump Orientation / Industrial Specs

One thing to keep in mind in this discussion is that these pumps are
industrial equipment.  Mounting recommendations, etc. are typically to
ensure design life.  While I don't see a design life specification on the
March site, I would guess that it is probably years of continuous operation.
If we were to assume that mounting vertically shortens the life by 95%
(worst case guess), and that the design life is 5 years continuous, then we
are left with 2190 hours of operation.  With a 2 hour mash, this is a mash a
week for 20 years.  I don't think I would be overly worried about decreasing
the pump's life in this application.

Mounting vertically does raise another concern if the pump head is on top.
Any leaks will flow down onto, and unless it is a sealed motor, into the
motor.  That could shorten (no pun intended) the motor life and yours.

Reif
Durham, NH






Return to table of contents


Date: Sat, 16 Oct 2004 07:46:17 -0700 (PDT)
From: Kent Fletcher <fletcherhomebrew at yahoo.com>
Subject: Re: Up and down... (pump mounting)

Jay responded to Dave:
> Well, not really.  Seeing as how the mounting plate 
> is on the same plane as the shaft, it's not too hard

> to figure out what orientation is vertical and what
> orientation is horizontal, as it relates to 
> /mounting/.  I think many people have gotten my
> comments skewed, here.  My whole reason for bringing
> B3's vertical mounting option into the thread here
> is that they sell a "pump mounting bracket" which
> is basically a slotted metal piece with 2 screw
> holes for attaching to a brew stand.  See part 
> #H357.  This can be used to mount the pump
> /vertically/.  That's what I was referring to.

Jay, take another look at the picture of B3's bracket.
 It's designed for the pump mounting plate to slide
into it, with the pump held in place by gravity.  Note
that it is longer ("up and down") than it is wide
("longways").  Now look at the shape of the plate on
the motor.  Looking from the pump end, it's 3.5" from
left to right and 3.125" from front to back.  If the
B3 bracket is installed as designed, with the holes
aligned vertically ("up and down") on a brew stand,
the pump can ONLY be linstalled in the proper
horizontal ("longways") position.  Relax, don't worry,
have a mag pump.

Kent Fletcher
Brewing in So Cal




		


Return to table of contents


Date: Sat, 16 Oct 2004 10:52:59 -0400
From: "Dave Burley" <Dave_Burley at charter.net>
Subject: Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals

/Fredrik

I suggest you learn a little more about thermodynamics in order to make use of 
your energy theme.

The Free Energy is  a constant value which depends on the reaction. The Free 
energy (del H-delST) can be calculated from enthalpy and entropy times the 
absolute temperature. The Free Energy of a total reaction needs to negative in 
order for a reaction to be POSSIBLE to proceed.

So if all these conversions of sugars are always energetically possible why 
doesn't sugar just transform to alcohol and carbon dioxide spontaneously?

The rate of a reaction is not dependent on the "energy" ( do you mean 
enthalpy?) difference between the two states. This rate is a kinetic 
phenomena. In the subject under discussion it has to do with things like 
transport phenomena and enzyme complexes.

In the kinetic discipline, these have been related to the <free energy of the 
formation> of a reaction complex ( e.g. a sugar molecule and an enzyme)  which 
combines reaction "thermodynamics" and kinetics to some extent by analogy.

You can think of this reaction complex energetically in terms of a hill. The 
lower the hill the faster the reaction will proceed at a given temperature. 
But the free energy of reaction complex formation does not comment on the 
overall thermodynamics of the total real reaction, which always must obey the 
basic rule of a negative value for the free energy to proceed.

Thus the enzyme performs the role of catalysing the reaction by giving the 
reaction a low Free Energy of reaction complex formation pathway via its 
complex with the reactants.

Most likely the reason a fermentation stops with residual fermentable sugar is 
too high alcohol which I believe has to do with disabling the enzymes complex 
formation, perhaps through hydrogen bonding, and flocculation which removes 
the yeast from the field of action. These are physical phenomena and not 
"energy flow" related.

Keep on Brewin'

Dave Burley 




Return to table of contents


Date: Sat, 16 Oct 2004 12:57:50 -0500
From: Alexandre Enkerli <aenkerli at indiana.edu>
Subject: Coffee and Beer as Hobbies

Our friendly moderator said:

> At the request of friend Arnold Neitzke, I have added the Coffee 
> Roasters'
> Digest to the portfolio of hobby lists on the HBD.
Sweet!!!!
Then we might have good homeroasting discussions with people who 
understand comparisons with beer!

Is it just me or is there a tendency for beer and coffee hobbies to 
become popular together?
Been talking with -S about similarities between homebrewing (beer) and 
homeroasting (coffee beans). Some of my comparisons are a bit stretched 
but there seems to be something in there. And although coffee's often 
compared to wine, there are several things in common between beer and 
coffee.
For what it's worth, I feel both drinks go well together and I often 
alternate between drinking coffee and beer during the same night. The 
flavors are compatible and physiological effects are interesting... ;-)

Cheers!

AleX in South Bend, IN
[129.7mi, 251.5] Apparent Rennerian



Return to table of contents


Date: Sat, 16 Oct 2004 16:43:41 -0400
From: ALAN K MEEKER <ameeker at mail.jhmi.edu>
Subject: modelling yeast fermentation/sugar utilization

Fredrik, You have taken on an almost Quixotic task in trying to model 
the fermentation process, good luck with this! Hopefully the information
alluded to by Dr. Fischborn and Dr. Waldrop will prove useful. With
regards to sugar utilization, Dave Burley recently said: 

"...my point is 
that any model ( which was the subject of my comments to /Fredrik) should not 
be serial but take into account all possible reactions. Some will be slowed 
down by the presence of other sugars and such, which I commented on, but need 
to be included in a comprehensive kinetic model." 

Again, this idea of parallel sugar utilizatiuon is incorrect, as confirmed by
Dr. Fischborn and Dr.Waldrop in their response to your post, so don't try
to include this in your model as you will be introducing error, making your
already difficult task that much harder. There are many detailed explanations
of this phenomenon in some of the more technical brewing texts and journal
articles. For explanations of the basic mechanism of metabolite repression
this can be found in any decent molecular biology or molecular genetics text.
In particular, the classic example of this form of gene regulation is the 
bacterial lac operon, the molecular details of which were worked out by 
Jacob and Monod in the early 1960s. A bit of poking around the web will 
undoubtedly provide even more information than you'd care to see. Good luck
Fredrik!

 -Alan Meeker
Baltimore, MD







Return to table of contents


Date: Sat, 16 Oct 2004 20:00:24 -0600
From: Bob Devine <bob.devine at worldnet.att.net>
Subject: link of the week - beer festivals

Beer festivals are fun. Here's a good and comprehensive collection:

http://www.beeradvocate.com/events/calendar.php

Bob Devine


Return to table of contents


Date: Sat, 16 Oct 2004 19:14:11 -0700
From: "zuvaruvi" <zuvaruvi at cox.net>
Subject: re. electric kettle

>From a private post:

>Is your new element low density style?  I brew with a 4500 W 220VAC element
>from HomeDepot which is supposed to be low density to prevent scale buildup
>in water heaters (~$25).

If I'm not mistaken, this is the same element I used, although it may have 
been the 6000w low density coil.  I've tried 4 different elements at 110 and 
220 over the last five years and haven't been satisfied with any of them. 
I'm going to natural gas; it's infinitely adjustable and cheaper in the long 
run.  Plus, I enjoy the sense of satisfaction I get from punching holes in 
walls and playing with galv pipe and especially enjoy conquering all the 
planning department hurdles enroot to a permit and final inspection.  And 
more importantly, I've had one too many metal tainted brews.

Dion, now that you mention the prune thing, I added 12 ounces of pureed 
blackened raisins (ala Pizza Port's Cuvee de Tomme) fifteen minutes from 
knockout, just before I went back into the kitchen to measure out the final 
hop/spice additions.  The fruit may have been the source of most of the 
smoke.

Chad Stevens
QUAFF
San Diego

P.S. Judges and Valued Entrants (398 entries last year), mark your calendars 
for March 4th & 5th, 2005.  America's Finest City is just around the corner. 
More to follow.... 



Return to table of contents


Date: Sun, 17 Oct 2004 00:51:06 -0400
From: "Pat Babcock" <pbabcock at hbd.org>
Subject: Rejection. I HATE rejection...

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

OK! I've resolved the issue with the UCE lists vs the subscriber list. You 
see, one of the lists I use to reject SPAM coming into the HBD domain has 
included entire countries and address space blocks in its list because certain 
countries and domains seem to promote SPAMmers. This has caused many 
subscriptions to be dropped in the last subscription probe. I have set up the 
server to discriminate between those blocks and the HBD subscriber list, and 
to defer to the subscriber list when in conflict.

What this means is that you can once again receive the Digest if you recently 
stopped receiving it (at the last PROBE).

First thing you should try is to resubscribe. If you get a UCE error in return 
for your efforts,  go to the http://hbd.org website, click the link for the 
FAQ, and follow the instructions for "Hey! Why is my mail into the Digest 
being rejected?!" (http://hbd.org/hbdfaq_table.shtml#boing) to resubscribe.


- --

See ya!

Pat Babcock in SE MI
pbabcock at hbd.org


Return to table of contents


Date: Sun, 17 Oct 2004 07:08:34 +0200
From: "Fredrik" <carlsbergerensis at hotmail.com>
Subject: Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals

Dave, I know well all the thermodynamics and the 
probabilistic definition of entropy and free energy, but I 
think you are still missing the point. Mastering 
thermodynamics doesn't mean you understand how a 
cell works. You don't seem to see the structure Dave, 
you just seem to look and the building blocks and
block dynamics like on a pool table. I think a biological 
organism is way too complex for you to ever be 
able to successfully model it terms of thermodynamics 
and molecular kinetics alone. As long as you just
think of it, then maybe it satisfies you, but I want to 
model it, and it has to be practical, anything that is 
overly complex and requires clusters of 
supercomputers is not a good idea.

When I started out as as student I had a very 
reductional philosophy, I would look into a politics book 
and see nothing but an application of what can occur in 
biological systems, further looke into a  biology book and
think that is simply an application of chemistry, which in turn 
is an application of molecular and atomic physics, which is 
an application of quantum field theory and particle physics. 
I was not intersted in applications, I was interested in hitting
the core of understanding our world. So I ended up taking
only these abstract courses, because I thought that was the
"point". 

But there is a slight flaw with that approach that I have 
now realized. You are missing the essence of self 
organisation at each step of reduction.

I don't regret taking the abstract courses, but I might have 
benefitted also from at least one course on evolutionary 
biology as well to see the other end of things. 

One difference between a biological system and chemistry 
is that there are too many possibilites for the chemistry to 
organize. The point is that evolution picked one for us, 
and it wasn't picked at random, it was picked with care.
This is the essence of life, and IMO far more profound 
that is probing into matter for yet smaller building blocks.
The actual configuration is NOT a coincidence as in (but 
one out of a billion) there is a logic behind it, and there
many reasons to respect the configurations evolutionary
process has selected. 

Understanding the building blocks is important, but it
is equally important to understand the rules of how they self
organize into coherent units, that even at some point start
to reproduce and gain consciousness. Look at us humans.
Try to understand human responses by means of molecular 
kinetics and thermodynamics Dave, and you will spend 
more than  a lifetime and still not make it.

> Most likely the reason a fermentation stops with residual
>  fermentable sugar is too high alcohol which I believe has
>  to do with disabling the enzymes complex formation, 
> perhaps through hydrogen bonding, and flocculation which 
> removes the yeast from the field of action. These are
>  physical phenomena and not "energy flow" related.

Thanks for the explicit suggestions.

1) As far as I understand the yeast flocculation is mainly an 
effect and not a cause. How would you explain *why* it
flocculates? I see no good reason for active yeast to 
flocculate? Can you elaborate this?

2) I agree the alcohol matters but the alcohol disabling of 
transporters + "flocculation" sounds unlikely to be a sufficient 
explanation (flocculation is no sufficient explanation IMO, it's 
mainly an effect). I don't see how that could consistently 
explain the diversion we see. Wouldn't we then see a larger 
correlation between alcohol level and maltotriose depletion 
than what I think we do? How would you explain increased 
attenuation from stirring? That wouldn't remove any alcohol. 
How do you explain the strain to strain variation? Do you 
suggest some strains have transporters that are more tolerant 
to alcohol? I thought the transporters are exaactly the same, 
anything else would seem weird too. The genetic machinery 
are the same.I suspect it has to be the rate of synthesis, 
regulation or the max density of transporters on the cell 
surface.

Can you elaborate the second point above Dave. I am 
certainly open for suggestions, but I have hard to merge
that mechanism consistently into something that lasts all 
the way.

 /Fredrik



Return to table of contents


Date: Sun, 17 Oct 2004 09:39:39 -0400
From: Bruce Millington <bmillington at verizon.net>
Subject: BONES Bash 2004 Competition

The Brewers of the Northeast Section proudly announces the return of the 
BONES Bash, to be held Saturday, November 6, 2004, at the Nodding Head 
Brewery & Restaurant in downtown Philadelphia, PA.  This will be the 
first leg of the Delaware Valley Homebrewer of the Year.  Entries will 
be accepted from October 10th thru November 1st, 2004.  For full 
details, please go to:
www.hbd.org/bones/

We will be using the 1999 BJCP guidelines.  All interested judges and 
stewards please contact Bruce Millington at bmillington at verizon.net.  
Judges and stewards are to report by 8:30AM, and begin at 9:00AM.  See 
you at the Bash!

Bruce Millington
Judge Coordinator


Return to table of contents


Date: Sun, 17 Oct 2004 12:32:05 -0400
From: "-S" <-s at adelphia.net>
Subject: Re: Attempt#2 Explianing idea on "Energy balance" / sugar residuals

I have to agree with Fredrick that his post was a bit maltreated on HBD.
Somehow the insightful question of yeast energetics as it relates to
low-attenuating yeast  was transformed into a tussle about a very basic
yeast feature - serial sugar transport.

Briefly on this side topic - There are three forms on cell surface transport
in consideration ... a/ pure passive diffusion, b/ facilitated diffusion by
enzyme catalysis and c/ active (powered) transport - method a/ doesn't seem
to be at all important in yeast sugar transport !  Studies have created
yeast with genetically defective transport mechanisms (b/ & c/) , and such
yeast cannot even survive on passive transport of glucose !  Any model that
begins by generally assuming passive diffusion of all sugars violates well
known results.

Back to energetics and low attenuation (please!).

I'd like to know how the difference in attenuation varies as we change the
fermenting conditions.   How does the attenuation difference vary when we
dilute 12P wort to 6P for example ?  What happens when we add nutrients or
oxygen ?  As a rule brewing yeasts can be coddled into fermenting to very
high alcohol levels by adjusting these factors, [see various articles on
very-hi-alc brewing and sequential feeding].  Perhaps low-attenuators(LAYs)
can also be coddled into complete attenuation and the methods required to
accomplish this may tell us why the LAYs quit early. [ That is my limited
experience anyway.  I've gotten quite high attenuation from WY1968 on a stir
plate for example].

So the transport of the sugars into the cell is a regulated system, and it
undoubtedly takes energy, at least to keep the system in a state of repair
(for example producing cell membrane transport proteins) and additionally to
power any active transport.

It is worth noting that yeast cells internally use a form of alpha-amylase
for the catabolic breakdown so maltose and maltotriose processing is
essentially identical.in form.  There is a difference in that a single G-G
1-4 bond cleave in maltose produces two glucoses (0.5 cleaves/glucose from
maltose) while for maltotriose it requires 2 cleaves per 3 glucose (0.66
cleaves/glucose from maltotriose).   Proteins don't stay intact very long
and are expensive to produce - so we can see there is a modest disadvantage
of  maltotriose vs maltose; it requires 33% more amylase action to process.

Another req for yeast is that they use a LOT of energy maintaining their
internal ion balance.  Yeast are required to expend energy to pump the
excess ions out and to pump the deficient ions in.  It requires real energy
to pump ions against the concentration gradient.  I once estimated that
something like 10% of the energy available when fermenting conventional 12P
wort may be used for ion balance, but that's a SWAG.  The real answer
involves the yeast cell membrane quality.   Better cell membranes are less
"leaky" and require less pumping but "cost" more to construct.   Obviously
there is "design tension" between membrane quality and ion pump operation
costs and this must be reflected in the yeasts genetics.  In brewery
fermentation the cell walls are typically best at the start of anaerobic
fermentation and worst at the end when the UFAs and sterols which constitute
the cell walls have been split among far more cells and far more area of
cell membrane.  Also late in fermentation the molar concentrations of solute
increases radically as a mole of maltose is converted to 4 moles of highly
cell-permeable ethanol, etc.  This means the osmotic pressure increase
substantially as the fermentation progresses and the pressure itself is a
stressor.

As a related note, wine yeasts (S.cerevis varieties) will accumulate
substantially higher levels of sterols than brewing yeast and then can
handle higher ethanol levels without 'coddling'(see above).   This sounds a
lot like the difference between the LAYs and high-attenuators(HAYs).
Perhaps LAYs have lower quality membranes.

In my experience the LAYs are often British ale yeasts which seem to a/ be
top fermenters (perhaps seeking oxygen?) or b/ require the 'dropping'
procedure which introduces oxygen and c/ flocculate like a stone before
terminal attenuation.  To me it *seems* *possible* that LAYs do not have the
ability to create enough sterols or UFAs to live anaerobically for a
sufficient number of generation to complete attenuation of typical beers.
If this is correct then LAYs should fully ferment lower gravity worts.

Perhaps the energetic cost of reproducing is lower for LAYs so they are more
likely to run out of sterols (by division) before they run out of sugars.
This certainly would not be the only example in nature of divergent surival
strategies of low-cost, higher-rate reproduction rates versus higher-cost,
higher-quality lower-rate reproduction.   Both can be successful.

Of course differences in other nutrients reqs, FAN, biotin, naicin, etc may
explain low attenuation.

==

Now if someone would explain the survival value of yeast flocculation to me,
please.  Where's the sense in non-sexual cells calling a 'huddle' at the
start of dormancy ?  Brewer & vintner's appreciate this property but
couldn't have influenced it (much).

 -S



Return to table of contents


Date: Sun, 17 Oct 2004 16:02:22 -0500
From: Eric Schoville <eric at schoville.com>
Subject: Competition Announcement: Franco-Belgian Challenge

The Madison Homebrewers and Tasters Guild are pleased to announce the 
2004 Franco-Belgian Challenge, a competition encouraging the homebrewing 
of French and Belgian style beers.  Beers from categories 18, 19 and 20 
of the 1999 BJCP guidelines will be accepted.

When: 10:00 am, Saturday, 13 November, 2004
Where: J.T. Whitney's Brewpub, Madison, Wisconsin

Entries must be received by Thrusday, 28 October.  For more information 
and registration materials, please visit http://www.mhtg.org.


Return to table of contents


Date: Sun, 17 Oct 2004 18:07:10 -0400
From: "Paul Clarke" <ptclarke at sympatico.ca>
Subject: Re: Electric Brewery

I have been using heat sticks based on Pete's design for several months now
and, overall, I'm quite pleased with them.
I have used them for 5 or 6 brews and they are standing up well, although
the DAP is looking a little abused and I may think about applying some more
soon.

Jodie, I just use a light switch to control each stick and turn it off and
on as needed.  However, to keep 6 gallons of wort going at a
rolling boil, you pretty much have to keep two sticks at full power.  The
only times I have felt a need to switch one off is during that first 5
minutes after the boil starts and it threatens to boil over.

You can see pictures of my sticks and "controller" at
http://www.bodensatz.com/gallery/album12

Paul Clarke
Ottawa, ON, Canada



Return to table of contents

---