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


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Contents:
  Heat of combustion of Propane ("A.J deLange")
  Re: Brewing Logic and Experimentation ("J. Ben Schafer")
  Experiments/experience Alexandre's suggestion ("steve.alexander")
  Herbal Express ("Eloy Butler")


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JANITORs on duty: Pat Babcock (pbabcock at hbd dot org), Jason Henning,
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Date: Sat, 05 Apr 2008 07:56:59 -0400
From: "A.J deLange" <ajdel at cox.net>
Subject: Heat of combustion of Propane

I completely forgot about the heat of combustion question

"Do you know, off hand, what the equation would be for the BTU's/lb of 
propane...."

The available heat when propane is fully combusted is about 45.8 M joule 
(mega joule)
per kg.  If you manage to condense the water vapor produced you can 
recover about
6% more.

A.J.


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Date: Sat, 5 Apr 2008 09:36:14 -0600 (CST)
From: "J. Ben Schafer" <schafer at cs.uni.edu>
Subject: Re: Brewing Logic and Experimentation


> For the widely popular and simple styles such as pale ale we ought to come
> up
> with a significant number of recipes that differ by one ingredient (yeast,
> base
> malt, water, etc).  Using this data we should be able to reach some
> meaningful
> conclusions.
>

Let me play devil's advocate for a bit - how do you adjust for the
non-ingredient variables?  The final outcome of a recipe is more than just
the ingredients involved.  Temperatures at various stages of the game
including into the fermentation time, water profiles, efficiency rates,
times spent at different stages of the process, pitching rates, heck even
thoroughness of sanitation will all have an effect on the final flavor of
the beer.

While I have done it myself, I would be hesitant to compare two beers
differing by one ingredient and make too strong a claim that the
ingredient swap caused the difference(s).

I don't remember whether it was on this list or one of the others I read,
but someone recently said "Give 5 brewers the same ingredients to brew a
beer and you are likely to get 5 different beers."

Now let me step away from the devil's advocate role.  I still think we
need more science, testing and "controls" to help us solidify our
knowledge and this discussion is GREAT.  I too hear brewers throw around
"facts" that I think are sometimes "old brewer's tales" passed from
generation to generation with no real merit.  We need ways to really test
these things.  I just wanted to point out we need to be very careful
because of the high degree of variables that go into each brew session and
final beer.


______________________________
J. Ben Schafer
Associate Professor
Department of Computer Science
University of Northern Iowa
Cedar Falls, IA, 50614
_________________________________________________
"Always behave like a duck --
   keep calm and unruffled on the surface
   but paddle like the devil underneath."
      -J. Braude


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Date: Sun, 06 Apr 2008 03:48:14 -0400
From: "steve.alexander" <-s at roadrunner.com>
Subject: Experiments/experience Alexandre's suggestion

Janitorial Cajole:

Despite being probed regularly by Pat Babcock (!!), it seems that some 
cosmic filter removes the most interesting HBDs from my inbox.  Such was 
the fate of #5315 with A.Enkerli's proposal.  [[As an aside I have all 
ISP filters off, so it was never received on this end.  I also receive 
HBD under two aliases and both regularly miss the same issue.  I could 
and probably blame Time-Warner]].
==

I suspect Alexandre is aware that there exist some brewing books along 
the lines of (what I imagine) is in Mr.This' cooking book.   Tho 'not 
specifically aimed at verifying or debunking brewing lore, I find 
Charles Bamforth's books refreshing and informative with a strong 
experimental basis behind his statements.  George Fix's last book, "An 
Analysis of Brewing Techniques" is IMO a sweet little compendium of the 
brewing experience of a well respected and knwledgeable brewer.

In the next paragraph Alexandre suggests "the reverse approach might 
work well [...] By aggregating large numbers of data points, we might 
get a more precise picture of different dimensions of brewing".   This 
is an idea that had first occurred to me  3+ decades ago while reading a 
nice little book called "Decision Analysis ..." by H.Raiffa.   Not a 
brilliant book, but a nice introduction  to a topic.  The Author 
introduced a method of making decisions for an 'optimal' outcome in the 
face of uncertain knowledge by estimating (quite crudely and 
subjectively) probabilities.   The book then veers off in the direction  
of exploring some of the human-psychological issues, an area that 
interests me less  [[we monkey-boys are stupid & have blindspots in our 
reasoning - I see that every day, ho-hum]].  Anyway the problem in 
making decisions by this method is that we have poor estimates for 
probabilities.    To bring this back to earth, say we want to make a 
malt-y tasting ale and we are considering the best yeast among WY1338 & 
WY1028; we usually rely on personal experience which can be quite 
limited.  It would be terrific to poll a much larger "experience base" 
for the answer.

The problem is not specific to brewing. but is a extremely common 
problem in all walks of life.  We must make decisions but we have 
insufficient information/experience, so we seek advise.   The 
traditional approach of leaving things to the "expert" has some severe 
limitations.   See about.com for examples of the old paradigm - the 
expert informing the masses from a pulpit/ex cathedra.  Generally solid 
information on  many topics, but paper thin detail, usually no reference 
to any background detail, and occasionally it's blatantly erroneous.  I 
don't care for this sort of advise since it is directly aligned with an 
appeal to an unnamed authority; a clear logical fallacy.

Another common approach to decision making when faced with limited 
information is to poll a forum like HBD.  We regularly see posts asking 
which brewing materials to choose, or which methods to employ to get a 
particular result.   This actually works pretty well, but there are 
problems.  Someone with good experience may not have time or the 
inclination to answer.  Still if a dubious answer is posted it is likely 
to be discussed or rebutted.  Better than nothing but it would be nice 
to get such an answer with google-like speed and some sort of 
reliability of result.

Most HBers have a distorted view of how the  "brewing lit", Journals 
such as JIB, MBAA-TQ, and ASBC, actually work.  98+% of the papers are 
"experiment" papers and usually have an extremely small topic domain; 
the comparative analysis of certain phenolics in two minor variants of a 
barley strain, for example.  A tiny fraction are "overview papers" which 
attempt to draw conclusions by a survey of many experiment papers.  In 
experiment papers we expect a great care in the methods, procedures and 
description, and a truthful accounting of the outcomes.  Each paper is 
presumably one good data point and not more.   The experimental 
"conclusions" are always the most interesting part, but also the most 
subjective.    So the journal method has very high standards for entry, 
but the method is basically a bunch of tiny high quality data "points of 
experience" papers appear and then tentative overview/conclusions 
appears and are debated & revised as needed.  It is extremely rare to 
see any experiment paper renounced, since it is just the report of a 
carefully observation, but the conclusions may be rejected based on a 
later/better analysis & information.  This seems like a far better model 
for deriving information from experience.

So what if instead of a few high quality data point (journal papers), 
and instead of the slowness an vaguaries of a forum response, we invite 
everyone to *record* their personal experience in a sort of database and 
make the information accessible in flexible ways ?  The data quality 
obviously drops compared to a journal, but we have so much more of it so 
that perhaps we can still draw good conclusions despite the "noise".  
Someone with a strong statistics background could have a field day with 
this.

My thoughts on the topic are both more grandiose and less restrictive 
and Alexandre's.   Since the Internet was new, and again when the "wiki" 
was invented I've thought that recording and organizing personal 
experience rather than just "informal and more formal experiments" 
related to brewing  could be made practical.  How to organize experience 
is a fundamental issue that has no simple answer and broaches the of 
knowledge engineering, AI and the semantic web (not here tho').  Still 
imagine a google-like tool that could inform you in a highly extracted 
way of the experience of countless others when comparing  brewing 
yeasts, espresso grinders of restaurant choice or which tires to choose.
- ---
Stepping back from the blue sky ...  I applaud "dean at brewsession.com" 
for offering to take a small practical first step onto new turf.  
Patton's quip, "A good plan violently executed now is better than a 
perfect plan executed next week" applies.  I will suggest that you not 
become too restrictive wrt to the quality & type of data & sources 
included.  So long as these are recorded (not personal data for sources 
of course) these can be accounted for in the analysis.

 -S





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Date: , 6 Apr 2008 22:39:25 +0100
From: "Eloy Butler" <decreasingpb6 at melscasa.com>
Subject: Herbal Express

This proves that size really does matter.
http://tunierane.com



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