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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
  CO2 saturation/nucleation (and life on mars) ("Fredrik")
  Re: Sanke Parts (Roger Deschner)
  High Gravity Beers (stewart.pounds)
  Useless information? ("Doug Moyer")
  Freezer not freezing (le Man)
  CO2 output measurement (ALAN K MEEKER)
  Carbonation of beer - can a soda stream be used? (Bill Velek)
  a little more on CO2 supersaturation ("Fredrik")


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Date: Tue, 13 Dec 2005 08:21:46 +0100
From: "Fredrik" <carlsbergerensis at hotmail.com>
Subject: CO2 saturation/nucleation (and life on mars)

Dave wrote...

> Now that I have Fredrik's attention. The carbon dioxide emission from a 
> solution of carbon dioxide in water is dependent on the rate of breakup of 
> these clathrates in equilibrium with the formation of these clathrates. If 
> this is the slow step in this kinetic series, that is what you will be 
> measuring, not the rate of formation of carbon dioxide. Therefore, your 
> measurements do not represent the rate of formation of carbon dioxide 
> from the fermentation. These reaction rates are, of course, temperature 
> dependent, as  is the saturation ( to which it is related) .

Hello Dave, yes this is the old issues we discussed before, and I still agree 
it's true that there is a chain of events interacting, and what the flow 
measurement measures is the rate of which case leaves the
fermenting wort. Also the liquid is supersaturated, and nucleation has a 
certain element of  randomness to it etc.

I really think we agree so far.

But this applies to many other measurements. Many things are dispersed in 
disturbances, and we have to deal with it. And we will. Maybe this is 
were we disagree, I don't know.

While it's well worth to point out again thse complexities I would to add 
again also that I consider none of these issues as "fatal enough" to
remotely void the information in the flow data. I think flow 
measurements are very valuable, even granted the issues.

It is not necessary to explain every single bubble, only the trends. There 
is also a lag between local CO2 production and escape through the fermentor, 
but these things can be guesstimated to a certain extent, in order the uncover 
some of those issues. We will still end up with some noise, that we will not 
understand, but we really don't have to explain every single bubble anyway. 
But the distrubtion of the bubble/gas flow statistics are bound to relate to 
fermentation activity via a set of dynamic relations, like production, 
saturation, nucleation etc. Also there is a limit to what extent 
these saturation stories can affect the trends. The fermenting wort is 
supersaturated, and this varies in nucleation bursts and stuff but it doesn't 
vary infinitely. The fermenting liquied won't hold unlimited 
amounts of gas. So this scrambling, while there, is under a 
certain amount of "control" and "limit".


So in summary this saturation and nucleation complexity doesn't worry me in 
the context that there are other complexities in brewing that I consider much 
worse to descramble. It is along with the temperature and headpressure tests, 
the best method I can think of.

I choose to focus on the opportunity here, not the lack of perfection. 

I think of use as here "organisms" feeding on information, and during times of 
information starvation it is not wise to reject data because it failed to be 
submitted in triplicate copies, or beause it has coffe stains all over it. We 
can afford be picky when we have data in excess, they we use 
only the most significant parts and leave the rest for later. 
But as a homebrewer trying to understand beer, and yeast, lacking a lab, 
I do not consider myself remotely having excess of 
information. So I will have to use alternative data sources to make progress.
Or should I go dormant until someone will donate me a lab? ;-) Each 
situation calls for different responses. That's my perspective in a nutshell.

So bring on the madness, I am starving.

 /Fredrik



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Date: Tue, 13 Dec 2005 03:32:56 -0600 (CST)
From: Roger Deschner <rogerd at uic.edu>
Subject: Re: Sanke Parts

Try Banner Equipment, www.bannerbeer.com. This is a beer tapping geek's
wonderland.

Roger Deschner                                            rogerd at uic.edu
"I didn't know you could pay for beer."
- --Michael Jackson, on National Public Radio, May 13, 2005


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Date: Tue, 13 Dec 2005 06:24:23 -0500
From: stewart.pounds at gm.com
Subject: High Gravity Beers


Last night I was at a Beer Appreciation Night at a local brewpub and the
guest speaker was Rex Halfpenny author of the Michigan Beer Guide. The
subject was high gravity beers. During the discussion Rex started telling
of brewery's that have been brewing beers in mid 20% alcohol range. I then
asked how this was possible since I was always told that even Champaign
yeast was only alcohol tolerant to about 15%. Rex's explanation was that
certain brewers ( Bo's in Pontiac MI ) where breading strains of yeast that
were able to tolerant alcohol levels in the 20% range. Is this possible?



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Date: Tue, 13 Dec 2005 09:30:47 -0500
From: "Doug Moyer" <shyzaboy at yahoo.com>
Subject: Useless information?

Bill Velek takes it upon himself to limit other brewer's interests:

"If you can find a way to _USE_ the data you collect, then that's great; 
otherwise, more knowledge -- like knowing how many steps an ant takes in 
mile -- is worthless."

Bill, if Steve Alexander feels that collecting data enhances his enjoyment 
of the hobby, then good for him. Why should he care if you, or others, are 
interested? It's not like his posts are preventing you from focusing on the 
parts of the hobby that interest you. Even if his data is completely 
useless, it is interesting to him (and probably at least one other). As 
such, it is just as valid as a frothy discussion of Clinitest....

There's plenty of room in this hobby for all sorts. Live and let live.



Brew on!
Doug Moyer
Troutville, VA

Star City Brewers Guild: http://www.starcitybrewers.org

Shyzabrau Homebrewery: http://users.adelphia.net/~shyzaboy/homebrewery.html




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Date: Tue, 13 Dec 2005 16:35:04 +0000
From: le Man <hbd at thebarnsleys.co.uk>
Subject: Freezer not freezing

Hello all,

Here is a puzzle for you?

I have a chest freezer with a converted thermostat that allows me to set 
a temperature between +35 and -35C. Temperature has been set to zero C 
for a period of lagering. . .  However we have had a cold spell here and 
the ambient temperature where the freezer is located is around 4C. Just 
checked the freezer temperature and it 4.9C. How can this happen? The 
freezer is working as I've turned it down and the walls where the coils 
are get cold, turn it back to Zero and leave it and the temperature 
stabilises around 5C.

TIA

- -- 
le Man ( The Brewer Formerly Known As Aleman )
Mashing In Blackpool, Lancashire, UK


- -- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.371 / Virus Database: 267.13.13/199 - Release Date: 13/12/2005



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Date: Tue, 13 Dec 2005 12:03:03 -0500
From: ALAN K MEEKER <ameeker at mail.jhmi.edu>
Subject: CO2 output measurement

Commenting on Ken Anderson's monitoring of CO2 output as a proxy 
measure of fermentation rate, Dave Burley said:

"The carbon dioxide emission from a solution of carbon dioxide in water is
dependent on the rate of breakup of these clathrates in equilibrium with the
formation of these clathrates. If this is the slow step in this kinetic series, 
that is what you will be measuring, not the rate of formation of carbon 
dioxide. Therefore, your measurements do not represent the rate of 
formation of carbon dioxide from the fermentation." 

I disagree. Since the fermenting wort rapidly becomes saturated by the 
CO2 produced by the yeast, the CO2 output you are measuring will be equal
to the rate of CO2 production (so long as you don't do anything drastic
during the measurement such as shaking the carboy). Temperature 
fluctuations should be of little concern in a controlled lager fermentation, 
however this may be of some importance if conducting an uncontrolled ale 
fermentation. 

Alan Meeker
Lazy Eight Nanobrewery  "Where the possibilities are limitless" 
Baltimore, MD




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Date: Tue, 13 Dec 2005 12:18:39 -0600
From: Bill Velek <billvelek at alltel.net>
Subject: Carbonation of beer - can a soda stream be used?

First, I want to thank A.J. ($600 tables) and Mike Sharp (re GAC), for 
their replies in #4908; both were very informative.

Next, I have a follow up question for Dave Burley from his Clinitest 
reply in #4909, which I also greatly appreciate.  Dave, at the end of 
your post you discuss carbon dioxide emission and "clathrates".  You 
indicated that shaking a bottle of beer -- the shaking containing about 
the same amount of energy needed to form a clathrate -- disrupts it so 
that the beer foams when pressure is released.

If you don't mind, I'd like some clarification.  It has been my 
understanding that carbonation of beer can be speeded up by agitation, 
such as with a keg-shaker or by manually rocking the keg.  I presume 
that CO2 is dissolved or absorbed by the beer quicker in that fashion, 
but am wondering about those clathrates you mentioned.  Is their 
formation time-dependent?  I ask because I know that if I try to open a 
beer right after dropping it (when I presume the clathrates have been 
disrupted), the beer will foam, but if I wait awhile (presumably for the 
clathrates to reform), then it will be okay.  So, if the can of beer is 
just sitting there, where does the energy come from to form, or reform, 
the clathrates?  Is it just the increased pressure from disruption of 
clathrates that remains in the can?  And interestingly, I have a link 
here which pertains to carbonation of soda -- 
http://www.sodastream.co.uk/gbretail/SP_HowTo.asp -- which I wouldn't 
think would be much different from beer unless beer contains a much 
higher rate of carbonation (I have no idea how they compare).  Anyway, 
if you will look at the video on that website, above, you will note that 
the water is carbonated _instantly_, without any rocking, and it doesn't 
foam even though the carbonation was added mere seconds beforehand.

I'm wondering about the clathrates (if they apply to water versus beer), 
and also wondering why this wouldn't be an excellent way to carbonate 
bottled beer if one were to switch over to twist-off bottles.

I'm interested in what folks think about this.

Cheers.

http://tinyurl.com/7zpob is my 'Brewing Glossary' with photos and links! 
http://tinyurl.com/99s2l compares HomeBrewers Team stats w/ other teams. 
http://tinyurl.com/axuol moderated group (now 310 member) EXCLUSIVELY re 
equipment for craftbrewers and small breweries. Please visit. Bill Velek



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Date: Tue, 13 Dec 2005 20:26:41 +0100
From: "Fredrik" <carlsbergerensis at hotmail.com>
Subject: a little more on CO2 supersaturation

just another addition to my first post...

Here is a somewhat related article that I thought might be of some 
interest. It is an article about CO2 pressure vs volatile formation, but
it does contain a side note on CO2 saturation.
http://www.asbcnet.org/journal/pdfs/backissues/35-0035.pdf
 
Under the give experimental conditions, the levels of supersaturation 
was correlated with the corresponding "equilibrium level" for a given 
CO2 headpressure, and as one would expect they found a significant 
correlation, and it's far from random. They found that the supersaturation 
coefficient (ratio of dynamic supersaturation and level and equilibrium 
level) is fairly constant throughout fermentation. The supersaturation 
coefficient also didn't seem to be much influenced by the CO2 
headpressure.

Moreover they found that the supersaturation coefficient varied 
linearly with agitation.
 
The article also suggests that once the *dynamical* "quasi equilibrium" 
is attained (= the supersaturation level) this is fairly constant throughout 
the most active part of fermentation if the headpressure is constant. 
 
This test refers to stirred fermentation and the experiment didn't cover 
the no agitaton domain - this is where we are - where the wort particles 
acting as nucelation sites would probably become a more dominant 
factor and the short time deviations would increase due to chaotic 
nucleation bursts. It's to be expected that as the agitation slows
(most of us don't agitate), the significance of random nucelations burts 
will increase and there will probably be larger deviations in data. 
But I expect it to be deviations a fairly determinable trend, and 
that's what we need.
 
So *while the test doesn't cover the relevant range* (no stirring) and 
that we are to expect some deviations due to chaotic bursts, it 
supports the concept that there exists a somewhat reasonable 
correlation between the supersaturation level, and any given 
nucleation activity, as in a given agitation, or a given amount of trub 
in wort or concentration of  nucelation sites. This is also what one
would "expect" based on normal kinetics and normal plausible 
argumentation.

I think the largest value is not to predict FG (this is easy enough to 
measure roughly anyway), it is the dynamic information contained in 
the graph. OG and FG gives us the end points and the graph helps
map out the process in between.

Eventually the full blown "poor mans" fermentation continous 
tracking I have in mind would consist of 4 basic transducers.

 - flow/bubble meter
 - internal and ambient temperature sensor
 - head pressure sensor, possibly one absolute pressure sensor and one 
differential pressure.

+ and A/D converter (many cheap ones for USB these days).
+ software of course (and this is where all the magic, and 
the full blown descrambling will have take place)

The tricky part is the flow meter. Either make one 
(bubble counter) or get a used one if you can, like Ken's.

 /Fredrik



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