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Mead Lovers Digest #1413
Subject: Mead Lover's Digest #1413, 19 March 2009
From: mead-request@talisman.com
Mead Lover's Digest #1413 19 March 2009
Forum for Discussion of Mead Making and Consuming
Dick Dunn, Digest Janitor
Contents:
re: ABV calculation? (dan@geer.org)
Re: ABV Calculations (docmac9582@aol.com)
Re: ABV calculation? (mail-box)
RE: ABV calculation? ("Bill Pierce")
Re: ABV calculation? (Marc Shapiro)
Re: ABV calculation? (stencil)
2009 Mazer Cup International - Entries Open! ("Vicky Rowe")
Sourwood Honey (chris herrington)
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----------------------------------------------------------------------
Subject: re: ABV calculation?
From: dan@geer.org
Date: Wed, 11 Mar 2009 13:58:39 -0400
> But out of about 6 different methods, no two seem to agree.
I concur that, at this late date in history, to have so
many non-congruent ABV calculations available is, ahh,
shocking if not worse. However, being a statistician by
training, I do what my kind tend to do -- throw out
anyone who won't tell me their formula (no undocumented
online calculators, in other words) and then I take the
best 4-6 of the remaining ones and simply average their
results, doing my own calculations using what formulae
there are. It is a ridiculous situation where with
identical input the observable disagreement in the
results of formulae are much, much greater than repeated
error of measurement in specific gravity determination
by hydrometer, but that is the way it is. Somewhere
upstream there are unacknowledged assumptions by formulae
writers on which their formulae are based -- how else to
explain the discrepancies? N.B., my own assumption in
averaging them, which is to say treating them as equally
valid, is that errors in those formulae are random
rather than malicious.
> So, now the kicker: The yeast I've used here is Lalvin
> D-47. The info sheet from Lalvin says this yeast has
> a typical ABV tolerance of "up to 14%."
I find yeast tolerance numbers to be, at best, an
ordinal scale. Again speaking as a statistician, by
"ordinal scale" I'm saying that the most I believe yeast
tolerance figures are good for is lining the yeasts up
in order of tolerance. I have come to find that no
yeast is evidently able to ferment itself into stasis
(as the reproving remarks my last thread on this subject
reinforced) and that the variability in performance
between batches using a comman strain far exceeds the
variability in rated tolerances between strains.
Someone will now remind us that yeast is a living thing
and hence chaotic. Well, OK, who can disagree with
that?, though, at the same time, I suspect that as
hobbyists we are busy rediscovering why commercial
concerns do not scrimp on lab-grade skills & equipment
in the name of consistency in what is, by our own
demonstration here, misleading precision in the
two-digit accuracy of yeast tolerance ratings, recipes
which call for three-digit accuracy in inputs, and
alcohol-by-volume formulae with six-digit coefficients.
- --dan
------------------------------
Subject: Re: ABV Calculations
From: docmac9582@aol.com
Date: Wed, 11 Mar 2009 16:45:48 -0400
Louis LeBlanc expressed confusion about measuring alcoholic content of his mead.
At first I thought this was an easy question - but after some research,
now I don't know the answer.
First some easy responses: 1.? Any method based on weight will not be
accurate because the sugar/water content of each honey will vary. 2.? I
have found that different honeys respond differently to the same yeast
in how far they will go in alcohol.? Also, initial oxygen content, amount
of nutrients, energizers, and how strong of a starter I used contributes.
3,? Measuring specific gravity/potential alcohol near the end of fermentation
will no be accurate because of the dissolved carbon dioxide in the fluid
and the tendency of bubbles to form on the hydrometer (which can be
reduced by spinning the hydrometer). 4.? Make sure your hydrometer is
calibrated.? Put it in plain water at the indicated temperature and make
sure it measures 0.000.? This does not check linearity, but even a single
point calibration is better than none.? I found I needed to apply a piece of
tape to the top of my hydrometer to make it read 0.000.? 5.? Temperature
is quite important.? I am glad you waited overnight before measuring
O.G.? I cool down samples to the temperature indicated on the hydrometer
(60F on mine) before measuring. 6.? NONE of the hydrometers OR tables
are totally accurate,?even for wine - much less for mead.? My Handbook
of Chemistry and Physics reports that the specific gravity of ethanol is
0.7893.? With wine and mead having other proteins and dissolved solids,
all of the hydrometers AND tables that I have seen have a specific gravity
of 0.000 = potential alcohol of 0.0%? This is known by most to be not true,
because many dry wines and some of my dry meads show a specific gravity
of less than 0.000.? Thus at 0.000 there is still some residual sugar.
7.? Changes in specific gravity are not simply due to conversion of sugar
to carbon dioxide and alcohol.? Some ethanol is carried off with the carbon
dioxide.? Some sugars,?proteins, yeast nutrients,?and minerals?are used
up in the production of yeast that then drops out of solution.?
8.? Now a real problem - The simple conversion of specific gravity to
potential alcohol is not so simple.? I have always simply used the alternate
scale on my hydrometer which (when put in chart form and extrapolated)
gives me 16.36% PA for your 1.120 SG and 1.36% PA for your 1.010 final SG,
and a resulting alcohol of exactly 15%.? This is slightly different from
your hydrometer.
However, I made the mistake of looking the the literature.? Although
most charts are simply copied from other sources, I found charts with
SEVEN DIFFERENT sets of conversions which gave original PAs which ranged
from?15.7% to 19.1% PA (many either 15.7% or 16.3%), and final PAs which
ranged from 0.5% to 2.2% (many either 0.9% or 1.4%).? I also found a
reference http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm?which had FIVE
different methods to calculate the ABV - mostly different from any of the the
literature chart values.? At least one chart (not on the extreme in values)
was for sugar water/alcohol and not grape juice or honey water/alcohol.?
I checked for standard methods, and of course hydrometers are not
routinely used.? Instead measuring weight before/after distillation, gas
chromatography, boiling point measurements (not as accurate), and other
tests are used.
My conclusion is that we might need a specific hydrometer that is calibrated
for honey water instead of grape juice to improve accuracy.? The scale
should be more realistic, starting with a SG of something less than zero
being 0% PA.? Even then, a show mead without nutrients would probably read
differently from one that had added nutrients.? For more accurate analyses
(such as for labeling for the feds), one needs to change analytical methods.
Carl McMillin
Brecksville, OH
------------------------------
Subject: Re: ABV calculation?
From: mail-box <mail-box@comcast.net>
Date: Wed, 11 Mar 2009 21:51:56 -0400
Louis LeBlanc wrote:
[snippage]
> This evening marked 15 days of activity, and 2 days after the real slowdown.
> I tested the gravity and found it to be exactly 1.010, which gives a gravity
> variance of -0.110. Now to figure out ABV.
>
> The question is how do I *really* calculate ABV from the gravity variance?
> According to Schramm, 1 lb of honey gives a gravity increase of 0.008 to a 5
> gallon batch. I've found this to be pretty accurate. He also says that that
> 1 lb honey will give a potential of 1% in alcohol. By that formula, I've got
> 13.75% ABV.
>
Schramm is estimating here. One pound of honey is about there, but it
can be more or less depending on the honey. You can get close using
this method but it'll always be a guesstimate.
> My hydrometer shows the 1.120 SG point is almost exactly 16% potential, where
> 1.010 is almost exactly 1.25% potential, giving 14.75% ABV.
This is what I'd use. It's the instrument you are using, your ABV
calculation will be as accurate or as inaccurate as the instrument is.
If the instrument is wrong then your OG and FG are wrong and no other
source will be able to give you a better measurement except advanced and
expensive methods.
> So, now the kicker: The yeast I've used here is Lalvin D-47.
Not so much of a kicker, really. As you've said, this is the expected
performance of the yeast, and it can fall short of that or exceed that
based on lots of factors. Not really a concern other than when you make
an initial selection of the yeast for your batch.
Cheers,
Ken Taborek
------------------------------
Subject: RE: ABV calculation?
From: "Bill Pierce" <BillPierce@aol.com>
Date: Wed, 11 Mar 2009 21:59:52 -0400
In MLD #1412 Louis LeBlanc raises questions about the various
methods and formulas for alcohol calculation. He has stumbled onto
a very geeky subject, but he seems to have embraced this interest,
so I doubt he will mind me upping the ante, so to speak.
Alcohol calculation is more complex than it might seem at first, and
there is more than one answer to the question. It depends on how
technical you wish to be, and how accurate you need to be. I will
address the second issue first. The methods he cites yield values
between 13.75 and 16 percent by volume, which allows for some
latitude, but this is a range that might be considered at least
useful. For one thing, how accurate are his specific gravity
readings, which I assume were taken with a hydrometer? What is the
resolution of his hydrometer, has it been calibrated against a known
standard, was the post-fermentation sample decarbonated, were the
readings corrected for temperature relative to the instrument's
reference value, and if so, using what formula? The answers to
these questions alone might yield a range of perhaps 2 percent.
Then we come to the various alcohol formulas. Some of these are
intended to be rules of thumb more than of science, and as such are
more for quick ballpark estimates than for strict technical
accuracy. Of the more scientific ones, my own formulas of choice
come from an excellent article now long out of print. The Summer
1995 issue of Zymurgy published "Brewing by the Numbers" by atomic
physicist and homebrewer Michael L. Hall, which remains in my
opinion the best treatment on the formulas used in brewing and
fermentation.
Because the formulas are based on extract weights (more accurate
than volumes for such calculations) and degrees Plato (the
percentage of sugar by weight in solution), the final value depends
on converting specific gravity to degrees Plato and calculating the
alcohol percentage by weight, then converting it back to alcohol by
volume. Unless you are truly geeky I won't bother leading you
through the derivation of the intermediate formulas, of which Hall
does an excellent job.
Charlie Papazian's simplified formula from "The New Complete Joy of
Homebrewing" is actually quite accurate, especially for the typical
gravities of beer:
ABV = (0.G. - F.G.) * 131.25
For the higher original gravities more typical of wine and mead, I
increase the multiplier from 131.25 to 134, but even then the
results are improved by only 0.2 percent compared to the most
accurate formulas.
If we use the figures for Louis LeBlanc's mead (O.G. 1.120 and F.G.
1.010) and the most accurate formula based on Hall's article, which
I have incorporated into my own brewing spreadsheet, the result is
14.77 percent ABV (by the way, this agrees with the alcohol
calculator in the popular brewing software ProMash). Using
Papazian's simplified formula and a multiplier of 134, the result is
14.73 percent ABV. As you can see, both results are very close and
well within the range reported by LeBlanc. I would consider this
also to be well within the margin of error of the instruments
(hydrometer and thermometer) used by homebrewers and meadmakers.
And finally a note about Louis LeBlanc's question as to the alcohol
tolerance of Lalvin D-47 yeast. As far as I'm concerned, the
published figure of "up to 14 percent" is a ballpark estimate based
on "typical" conditions. The variables are many, so I don't find it
surprising at all that some people might well achieve higher alcohol
values (and some less). There's a reason they say "your mileage may
vary."
Brew on!
Bill Pierce
Cellar Door Homebrewery
Burlington, Ontario
------------------------------
Subject: Re: ABV calculation?
From: Marc Shapiro <mshapiro_42@yahoo.com>
Date: Wed, 11 Mar 2009 19:27:38 -0700
"Louis LeBlanc" <brew@fayreforest.net> wrote:
>
> The OG was exactly 1.120, which was my target...
> This evening marked 15 days of activity, and 2 days after the real slowdown.
> I tested the gravity and found it to be exactly 1.010, which gives a gravity
> variance of -0.110. Now to figure out ABV...
> My hydrometer shows the 1.120 SG point is almost exactly 16% potential, where
> 1.010 is almost exactly 1.25% potential, giving 14.75% ABV...
> If I run through Charlie Papazian's formula, I multiply the variance by 105
> for 11.55% ABW, then multiplying that by 1.25 for 14.43% ABV. I seem to
> remember somewhere else said multiply by 131 to get ABV, where Charlie's
> formula is actually multiplying by 131.25. That's close, anyway - and is
> actually very close to the calculator at
> http://www.angelfire.com/wi3/johnsons/abv1.html. In fact, this is the only
> two methods I've found that even remotely agree.
Well, the calculator on my site, 'The Meadery',
http://mysite.verizon.net/mshapiro_42/ then click on the 'Calc' button,
shows 16.3% for S.G. = 1.120 and 14.9% for S.G. = 1.100 (not too far
from what your hydrometer says). I, too, am a numbers guy, but when we
are talking about fractions of a percent in the volume of alcohol I
think that an EXACT number is not all that vital. It is also not
possible by any formula. If you really want an absolute, exact number
then take a sample to a lab and have it tested.
- --
Marc Shapiro
mshapiro_42@yahoo.com
------------------------------
Subject: Re: ABV calculation?
From: stencil <etcs.ret@verizon.net>
Date: Thu, 12 Mar 2009 17:04:45 -0400
> [ ... ]
>
>The OG was exactly 1.120,=20
> [ ... ]
>I tested the gravity and found it to be exactly 1.010, which gives a =
gravity
>variance of -0.110. =20
Shoosta minoot: 1.120 was the specific gravity of a
solution of sugar in water, which is the liquid most
hydrometers are calibrated for.
But the 0.010 figure is the reading of a soution of sugar,
water, *and alcohol.* 0.010 is *not* the specific gravity
of the solution. The actual sugar content of your mead is
much greater than the 10 gravity points displayed: the
less-bouyant alcohol lets the hydrometer float sink more
deeply.
The Papazian/Angelfire formulas attempt to correct for the
presence of the alcohol, and seem to agree in the 13.75 ~
14.25 range, which is consistent with the advertized
capability of the yeast. Given the precision of the
instrument that's not too big a ballpark.
If you want real fun, contact the revenue services of your
own and some neighboring States and ask them for the
official rule they want breweries and wineries to use, to
compute ABV for tax purposes.
gds, stencil
------------------------------
Subject: 2009 Mazer Cup International - Entries Open!
From: "Vicky Rowe" <gotmead@gotmead.com>
Date: Fri, 13 Mar 2009 10:04:57 -0400
Hi all!
Gotmead.com is proud to announce that entries are OPEN for the new Mazer Cup
International Commercial Mead Competition. We hope you'll enter, and good
luck!
The MAZER CUP INTERNATIONAL - HOME COMPETITION is an AHA and BJCP sanctioned
home-crafted mead competition sponsored by GotMead.Com and an organizing
committee of home mead makers, and mead enthusiasts world wide. The
competitions will be held at the Boulder Outlook Hotel in Boulder, CO.
There will not be a festival this year, as we are ramping up, so only the
competitions will be there. If you wish to attend, we ask that you help. So
if you have experience working a competition, and would like to come to the
Mazer Cup, contact our Volunteer Coordinator at volunteers@mazercup.com.
For almost two decades the most well known name in mead competitions has
been the Mazer Cup. Created by Ken Schramm (author of "The Compleat
Meadmaker"), Dan McConnell and Mike O'Brien, the annual event quickly
became the world's most recognized home meadmaker competition, bringing
together respected, accredited mead judges and entries from hobbyist
meadmakers across North America. Even though no Mazer Cup competitions
have been held for the past few years, there has never been a more widely
recognized event in the world mead community.
Likewise, in recent years the International Mead Festival (IMF) and last
year's International Mead Association (IMA) Commercial Competition served to
increase the visibility of commercial mead producers by conducting an annual
commercial judging and award ceremony in Colorado. Although the IMA/IMF is
no more, the owners of Gotmead.com, the internet's premier source for
everything having to do with mead, has taken up the torch and will sponsor
both commercial and home competitions the weekend of April 17-19, 2009, once
again in Boulder, Colorado. With kind permission from Ken, Dan and Mike,
this new commercial/home annual event will be called the "Mazer Cup
International."
We cordially invite you to enter your meads in the 2009 Mazer Cup
International (MCI) mead competition. This premier event will allow you to
showcase your products in a truly world-class venue, get the chance to say
you won in the Mazer Cup, and get fantastic prizes, including custom-made
mazers for all those placing! We're collecting a great bunch of extra prizes
of things like gift certificates, mead and other great swag!
The event will be conducted in much the same manner as last year's IMA home
competition. In fact many of the folks who worked so hard to make last
year's event the success that it was, are signed up to help to run this
year's MCI. The judge pool will again be drawn from a cross-section of top
commercial producers, as well as other respected names in the mead industry.
Ken Schramm will again be judging in both the commercial and home
competitions. If you would like to attend and judge, please email
Judge.Director@mazercup.com.
For this year's competition, each entry (Beer Bottles: Two or three 12 oz
brown or green crown capped beer bottles. Crown caps must be plain or
blacked out with permanent marker.
Wine Bottles: Two or three 375 ml clear or green wine-style bottles with
cork closures. Corks may not bear any designs and may not be sealed with
wax, foil or heat shrink capsules.) will be charged a $6.00 entry fee. Those
who cannot use Paypal may enter and pay by check (see entry forms). Details
of the entry process, including delivery deadlines for your entries,
submission addresses, and procedures are available online at
www.mazercup.com under the Home Resources tab. Deadlines for entries to
arrive is April 3, 2009.
Last year the IMA Home Competition showcased over 200 meads. This year's
event should be even bigger. We look forward to your participation in the
first ever Mazer Cup International, infusing old traditions with new
promise!
Wassail!
Vicky Rowe
Petar Bakulic
Competition Directors
Owners, Gotmead.com - Main Sponsor
------------------------------
Subject: Sourwood Honey
From: chris herrington <asby0@yahoo.com>
Date: Fri, 13 Mar 2009 12:55:16 -0700 (PDT)
Hey Fellow Meadsters,
I have never tried sourwood honey. Have any of you used this honey to
make mead? and if so...how is it? I've looked online and from the entries
I've seen about it, it is very appealing. It has been described as rich
and buttery. The best honey I've used is Tupelo from Florida and Orange
Blossom from Florida and California. Tupelo's flavor can best be described
as having a hint of apples and cloves. So, if you've used Sourwood please
describe its character.
Chris
------------------------------
End of Mead Lover's Digest #1413
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