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HOMEBREW Digest #3838
HOMEBREW Digest #3838 Mon 14 January 2002
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Digest Janitor: janitor@hbd.org
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Contents:
Carbonation calculator ("Steve Jones")
IBU Calculations In ProMash (Jeffrey Donovan)
Hops Calculations (AJ)
Re: Force Carbonation & Keg Cooling ("D. Butler-Ehle")
Promash hop calculations (Pat Babcock)
Paulaner Hefe-Weizen Clone Recipe? ("Jodie")
What's the cause ...... (Andy Woods)
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Date: Sat, 12 Jan 2002 09:00:31 -0500
From: "Steve Jones" <stjones1@chartertn.net>
Subject: Carbonation calculator
In response to the recent question about calculating pressure on force
carbonating, I've built a javascript calculator that isn't limited to a
specific range of temps or volumes CO2.
I've not tested it yet for Netscape, but here is a link to my brewing
calculators page. On it is the calculator for force carbonation, among
several others: http://users.chartertn.net/franklinbrew/tools.htm.
Steve Jones
Johnson City, TN
stjones1@chartertn.net
http://users.chartertn.net/franklinbrew
------------------------------
Date: Sat, 12 Jan 2002 06:51:52 -0800
From: Jeffrey Donovan <jeffrey@promash.com>
Subject: IBU Calculations In ProMash
Richard,
>Richard Foote wrote:
>I have been using ProMash for a few months now. One thing that keeps
>hitting me is the hop bittering calculations. It seems to take way less
>hops to achieve a desired bitterness level than I was accustomed to over
>many years of using long hand calculations and other brewing software.
Ok I will try and do my best to answer this question Richard, hopefully
something in the following statements will click for you:
1) The underlying formulas for all of the hop IBU calculators are for the
most part identical, it is the utilization calculation that is different in
each. You mention you feel the numbers are too high and that you are using
the default setting in ProMash. The default is the Rager calculation, and I
personally would agree that Rager numbers are usually a bit high, hence you
would use less hops. Have you tried using any of the other formulas such as
Tinseth or Garetz? I personally use Tinseth's formula, and most of the
brewers I talk to feel Tinseth is the most accurate of the three. Both
Tinseth's and Garetz's formula will give IBU values lower than Rager. The
reason we set the default to Rager is that this is the formula that has
been published the longest, and most brewers are familiar with it (most IBU
utilization formulas, with the exception of Tinseth, are based on Rager's
work).
2) I have had the opportunity many times to take my own beers to a lab and
have them analyzed. Again, the Tinseth formula's prevail as the best fit in
almost every example (best fit, not exact match). However, I can tell you
right now that IBU calculations are *not* mathematical truth, nor will they
ever be. The best we can do is be accurate in the equations presented, and
we have had all of our equations independently verified by their respective
author.
If you would like to see how the different formula's do stack up in the
Lab, I refer you to Louis Bonham's excellent article written for the now
defunct Brewing Techniques magazine.
http://www.brewingtechniques.com/library/backissues/issue7.1/bonham.html
3) What version of ProMash are you using? One problem we have had in the
past is that we include in the download section separate version for both
Home Brewers and Pro Brewers. While the actual program is identical, the
system settings are set to each scale accordingly. Now, in earlier version
we set the "Kettle Utilization" factor in the pro-scale settings to
accurately reflect the majority of kettles within the 17 bbl range .
However, we quickly discovered many homebrewers were downloading the pro
version because they thought the versions were different, and then *not*
resetting the kettle utilization factor to accurately reflect smaller scale
brewing systems (if your brewing 25 gallons or under this setting should be
set to 1.0). In version 1.6 we changed this so that each version (when
downloaded) defaults to a value of 1.0, leaving it to the pro-scale brewers
to set their correct value.
4) If you want to provide a example of the formula you use in you hand
calculation, or name the other software you are using, I could perhaps be
of more assistance in determining the discrepancies you are seeing.
Finally Richard states:
>figure how to get back into wherever I need to go to change it.
Goto the System Settings, Hop section. The default is set to Rager. All the
variations are outlined in the help screens, so just press the "Help"
button in the system settings, hop section to get a full rundown.
I hope this helps some Richard. If you'd like to talk more regarding this
subject please feel free to contact me via email (jeffrey@promash.com) or
visit our Message Board on the ProMash website.
Cheers!
- Jeff
Jeffrey Donovan
Beer Engineer
The Sausalito Brewing Co.
jeffrey@promash.com
jeffrey@beerengineer.com
http://www.promash.com
http://www.beerengineer.com
------------------------------
Date: Sat, 12 Jan 2002 22:19:45 +0100
From: AJ <ajd@zai.com>
Subject: Hops Calculations
Rick Foote asks about the hop utilization calculations in ProMash. The
ProMash bitterness calculators cannot be expected to accurately predict
the actual bitterness of your beer any more than any other method can.
There are simply too many variables. ProMash accounts for many if not
most of them. You have a choice of three models (Rager, Garetz and
Tinseth) for actual isomerization as well as a model for diminution of
alpha acids over time. The reason there are three models is beacuse no
one has been able to pick a "correct" model and that is, at least in
part, because if the perfect model were stumbled across, it would be
hard to verify it. In order to do that one would have to relate
something measureable in the hops (alpha acid percentage) to something
measureable in the beer (bitterness) but this last is a subjective
quality. Brewery labs do measure alpha (and beta) acid levels in hops
but this is by no means a perfect measurement. Simialrly, brewery labs
do measure the absorbance of a gasoline extract of the beer at 275 nm
resulitng in the BU values which "express the bitter flavor of beer
satisfactorily".
Everyone agrees that utilization (percent of hops resin that gets
converted to bittering principal) depends on the length of the boil and
most agree that it depends on the concentration of the wort. It also
depends on kettle geometry and a host of other factors. What this means
is that the differnce that a particular brewer sees in utilization
between an hour's boil and a half hours's boil may not be the same as
seen by another brewer and that implies that it is unlikely that any
particular model will exactly match the results any brewer would obtain.
About all that can be done about this is to try to correlate the
bitterness of the beer with the expected result. Without measurement
this is difficult to do but I think an educated palate can guess
bitterness to within plus and minus 5 or perhaps even plus and minus 2
with lots of experience with beer similar to the beer being tested. This
means that the brewer at a micro or brewpub can probably maintain his
output to within something like those limits. The problem, of course, is
that we don't have values for reference beers. Pilsner Urquell is at
about 35 BU and American Megaswill at about 14 i.e. near threshold.
Brewers never put bitterness data on their labels (it's rare enough to
see even ABV in the US).
Even with measurement you are likely to be surprised. I do measure the
bitterness of most of my beers and, where the hops are from a well known
supplier and have been kept frozen I'll see things like a measured 46
for a predicted 42 or a measured 17 for a predicted 15 but where I've
had to measure the hops alpha myself (rather than rely on a packagers
information) because the hops came in ziplock bags from the club buys,
I've had some real surprises notable among which was a pils that was
supposed to come out 45 and measured 70 (which, after lagering for a
year turned into a really nice beer).
A.J.
------------------------------
Date: Sat, 12 Jan 2002 16:36:44 -0500
From: "D. Butler-Ehle" <ulfin@portup.com>
Subject: Re: Force Carbonation & Keg Cooling
Doug Hurst writes:
>
>You can force carbonate your keg at room temperature. Just pump your
>keg up to about 30psi and let it sit a couple of days. Check it twice a
>day and re-pressurize as needed.
If I'm in a hurry, I can carbonate it in about 10-20 minutes.
Of course it works best when the beer is chilled. (Look at
the charts: CO2 solubility skyrockets as temperature drops...
if you have any way to chill it at all, do so.) I have done it with
warm beer too, though, but it takes a lot longer. (BTW, I'm
refering to Cornelius-style soda tanks here, not beer kegs.)
I crank up the pressure and shake the keg 'til either I don't hear
the gas rushing in or my arms get tired. Rest and repeat as
needed.
Note, however, that the fuller the beer tank (i.e., the less
headspace), the less vigorously I'm able to shake the tank,
lest I get beer splashing up into my gas line (and I hate that
[btw, opaque tubing is designed to hide spots and yeast
sediment; I recommend using clear hose for everything,
so you can actually see that it needs to be cleaned/discarded
{except maybe the drain tube from your drip tray; you don't
want to see what's growing in that}]).
The splashing can be avoided by removing the gas disconnect
before shaking, then reconnecting it to give the tank another
charge, and repeating. Unfortunately, if you don't have much
headspace to pressurize, you won't be adding much CO2 with each
charge and it'll take a lot of reps.
When I guestimate that it has enough, I shut off the gas, give it
a final good shake (to ensure that the head pressure has reached
equillibrium), let it settle for a few minutes (to reduce foaming
due to turbidity and to allow incidental liquid to clear from the gas
plug's draw tube), then check it with my pressure gauge(*).
With pressure and temperature readings and a target for vol CO2,
a quick look at a chart (I use Byron Burch's values as presented by
Dave Miller in _Brewing the World's Beers_ [I think it's also in his
_Homebrew Guide_]) tells me how close I am.
If I overshot, first I try to convince myself not to worry about
it and figure that giving it a shake after I've served a few pints
will drop it into range. However, if determine that I can't live
with it that high, I (carefully) bleed some off using the pressure
relief valve in the lid (some very old models don't have them).
Give it a good shake, let it settle, then recheck the pressure.
>To serve, you will have to reduce the
>head pressure to about 4psi (depending upon your tapping/beer line
>configuration)
Quite so. That's is a point that many homebrewers don't quite
understand. The pressure needed to maintain your carbonation
at your tank temperature is not necessarily the same pressure
needed to force the beer through your system. When they're
not the same, you either have to serve the tanks quickly or
regularly re-adjust your carbonation level because the
dispensing pressure is too low or too high to maintain it.
Commercial beverage dispensing installations are individually
designed such that the needed dispensing and maintenance pressures
will be equal. They adjust hose diameter, length, resistance;
vary the storage temp from the dispensing temp; add compensators
or restrictors; change rise (or fall) from tank to tap; or even add
non-soluble gas.
Be careful connecting a warm, carbonated keg to a gas line that's
set to dispensing pressure. The backpressure may drive beer
foam into your regulator (I don't trust the check valves to
protect me). Don't connect the gas until serving it has lowered
the head pressure.
>There are a couple of ways to cool it. You could fill a couple of
>growlers from the tap and cool them in the refrigerator
You may lose a lot of the carbonation as you draw from the tap
at room temp; warm beer can't hold its breath as well as cold beer,
and is much more sensitive to aggitation. Overcarbonating it a
little might help some.
Chillin' in da U.P.,
Dan Butler-Ehle
[411.4, 327.6] Apparent Rennerian
(*) My gauge is a constructed of
a disconnect (gas ball-lock x 1/4" male flare nipple)
a female adapter (FFL x FFL)
a quarter-turn stopcock without check valve (MFL x 1/4" MNPT)
a 3-way female union T (FNPT)
a 60 psi pressure gauge (MNPT)
another stopcock (MNPT x MFL)
My gas hoses have FFL swivels.
With stopcocks at either end of the gauge tool, I don't have to
disconnect anything to check pressure or to keep beer out of
the line if I'm shaking it vigorously.
------------------------------
Date: Sat, 12 Jan 2002 17:07:32 -0500 (EST)
From: Pat Babcock <pbabcock@hbd.org>
Subject: Promash hop calculations
Greetings, Beerlings! Take me to your lager...
Richard asks about ProMash hop bitterness calculations...
> I have been using ProMash for a few months now. One thing that keeps
> hitting me is the hop bittering calculations. It seems to take way less
> hops to achieve a desired bitterness level than I was accustomed to over
> many years of using long hand calculations and other brewing software.
> What gives? Has anyone ever checked the accuracy of ProMash by having
> hopped wort samples analyzed. I know ProMash allows you to choose from
> three different calculation methods. I use the default method. Can't
> figure how to get back into wherever I need to go to change it.
>
> Open discussion of this would be most welcome.
Odd! I have to wonder what hand calculations you are using, or
what the other software might have been using? I know that
Jeffrey Donovan, the software's architect, had the calculations
reviewed by Rager, Tinseth and Garetz, and they've concurred
with his algorithms for their hop utilization calculations. I
also know that he has implemented every possible variable to
those calculations upon which you have control on your
brewing.
Rather than truck on down the road of formal analysis, why not
use your senses? Are the beers brewed using ProMash-calculated
recipes much different than previous renditions? If so, which is
closer to the target style? Were you, perhaps, overhopping
before?
Still, I'm betting that the problem is that you were using a
calculation method other than the default in ProMash, so your
problem lies in not being able to fathom how to change the
settings. I can fix that!
The key to most disparities between ProMash and other methods is
that ProMash leaves nothing to assuption - you need to set it
up! You can select calculation method, and tweak utilization for
mash and first wort hopping methods (!) as well as adjust the
utilization scale factor for your kettle size. Plus, you can
CHOOSE whether to adjust utilization for plug and pellet. You
must, however, set it up.
These are all set very simply from the "Options" pick on the
ProMash menu. From there, pick "System Settings" (only pick
under that menu :^), then click on the "Hop Calculations,
Utilization and Storage" button. Hit the radio button for the
desired set of calculations, hit "OK". While there, set the
other variables affecting the hopping rates as they pertain to
your brewery (mentioned above) then click "Save As Default".
You're now golden! Set the calculation to what you used before,
and I'll bet the hopping levels become a bit more familiar :^).
Another point: hopping rate calculations and the algorithms to
implement them are not "science" - otherwise, there wouldn't be
Garetz, Tinseth and Rager methods; there'd be a "Hop Calculation
Formula" accepted by all (and I don't believe any commercial
brewers are using one of these three methods for estimating
hopping rates, so there's even more). Each of the three are
estimated predictions against the reality, and each is different
with its own error function. Automation of such formula can
induce additional error (or difference) from your hand
calculations based on the precision of variables maintained in
the calculation. Typically, you won't even notice the
difference; however, if there is a small difference between your
hand calculation and that of ProMash, this could be the source
as well (never bothered to compare. I selected my favorite
hopping rate calculator, and noticed no appreciable change to my
hopping schedules from the many years I'd brewed without PM.)
One man's answer. Others?
- --
-
God bless America!
Pat Babcock in SE Michigan pbabcock@hbd.org
Home Brew Digest Janitor janitor@hbd.org
HBD Web Site http://hbd.org
The Home Brew Page http://hbd.org/pbabcock
[18, 92.1] Rennerian
"The monster's back, isn't it?" - Kim Babcock after I emerged
from my yeast lab Saturday
------------------------------
Date: Sun, 13 Jan 2002 10:05:35 -0500
From: "Jodie" <jodie@ga.prestige.net>
Subject: Paulaner Hefe-Weizen Clone Recipe?
Yesterday my husband and I found ourselves waiting for a table at The $3
Cafe in Kennesaw, GA sitting at the long bar in front of the beer coolers.
Being a new brewer we figured we'd try something new--research you know.
Since we have both gravitated toward wheat beers I suggested the Shiner
Hefeweizen. Great label and, oh, nice beer. We shared two before we were
called to the table.
When we ordered our burgers my husband asked for another hefeweizen. The
waitress returned with a Paulaner. Wow! Even better. This one was spicier
than the other, with almost a clovely touch. Winner!
So, of course we now want to brew a similar beer.
Can anyone direct me to a recipe to replicate this brew? As I mentioned,
we're just beginning and don't have a mash set up (yet, but I see that
coming! ;) ) so a malt/partial grain recipe would suit us at this stage.
Thanks for any help,
Jodie Barthlow
------------------------------
Date: Sun, 13 Jan 2002 23:00:34 -0500
From: Andy Woods <woods_a@ACADMN.MERCER.EDU>
Subject: What's the cause ......
Hello all,
Im having a tough time evaluating a fault in a beer made by a friend. He
made a clone of a Heineken Special Dark with Kolsch yeast. At the time of
racking and bottling, the flavor was very good. But when tasting a finished
bottle the flavor was gone, very bland, had good head when pouring, but no
bubbles afterwards. I am fairly sure that it isnt phenolic cause of my recent
bouts with infection. It has been conditioning for 3 weeks, and like I said,
is very bland, similiar to a stale soda.
Any suggestions??
Andy Woods
woods_a@acadmn.mercer.edu
------------------------------
End of HOMEBREW Digest #3838, 01/14/02
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