by Nicholas A. Franke (firstname.lastname@example.org)
In the July 6, 1995 issue of the Digest (HBD #1774), I
requested information on making alcohol-free beer from the
collective. My motivation for making alcohol-free beer was
that a friend of ours had recently become pregnant but still
wanted to have an occasional beer. I thought I would provide a
summary of the responses I received and my experience with
making low alcohol beer.
I want to thank everyone who responded to my request.
All of the responses were very helpful. I received twenty-four
responses to my post, which provided the following input:
Coincidentally, the Fall 1995 issue of Zymurgy
contained a small blurb regarding an article written by Dr.
Siegfried Gunther and Stefan Vetter for Brewing and Beverage
Industry International (April 1994 edition) regarding
alcohol-free brewing methods. That article divided methods
into "biologic" and "physical". The three biologic methods
- 4 responders suggested using heat (78-82 C) to
remove the alcohol from regularly-made beer;
- 4 responders suggested freezing regularly-made beer,
and pouring off the alcohol (that would not freeze at the
temperature water freezes at). Most of these responders were
very pessimistic about the heating method, claiming that it
would ruin the flavor of the beer;
- 2 responders suggested making the beer with non- or
low-fermentables. The primary suggestion was to make the beer
entirely with Cara-pils, which would give an O.G. of no more
than 1.010, and thus keep fermentation and alcohol production
at a minimum;
- 1 responder suggested that using a reactant that
would turn the alcohol into a type of salt might be a
- 1 responder felt that it was too expensive and
impractical for a homebrewer to make non-alcohol beer;
- 7 responders though that pregnant women should just
drink regular beer in moderation, and that reports of
detrimental effects of moderate alcohol consumption on fetuses
were largely exaggerated;
- 3 people then responded to those posts that any risk
alcohol might pose to fetuses was too large to take;
- 2 responders suggested that non-alcohol malt
beverages be substituted for beer during pregnancy.
Specifically, a German product called "malzbier," and a
Hispanic product called "malta goya," were suggested.
1. Interrupting fermentation with a one minute
pasteurization at 140 F at the desired alcohol level;
2. Brewing a low-gravity beer and using yeast of the strain
Saccharomyces iudwiggii, which will ferment only simple sugars;
3. Mixing the yeast and wort at 32 F and filtering the yeast
out after a rest period (duration not specified).
The three physical methods noted were:
1. Heating the finished beer at atmospheric pressure. The
authors noted damage to the beer that made this method
2. Reverse osmosis. Removing alcohol by passage through
diaphragms by use of pressure gradients;
3. Dialysis. Passing the beer through fibers that are
bathed in a counterflow dialysate that produces a concentration
Armed with this information, I decided to merge two of
the most popular concepts together. I decided to brew a fairly
low gravity beer, and then to freeze it after fermentation so
that the alcohol could be poured off. For reasons that I will
go into later, and although not planned, I also ended up using
a third method of removal--heat--but in a different way that
The recipe I used was for a pale ale-type beer, and
consisted of the following:
3# Domestic Malted Barley
1.75# Munich Malt
12 ozs. Canadian Wheat
6 ozs. English Crystal (80L)
2 ozs. Domestic Crystal (120L)
.88 ozs. Northern Brewers (8.2% A)--60 mins.
2.69 ozs. Liberty (2.7% A) --10 mins.
Wyeast American Ale yeast (#1056)
The mash was a standard infusion mash, except that the
Cara-pils was not added until the mash was brought to 158 F.
The boil was for 90 mins. A 300 ml yeast starter and 3 tsp.
yeast food were pitched into 6 gals. The O.G. was 1.031.
Primary fermentation lasted for four days at 68 F.
Secondary fermentation was for another ten days at 68 F. F.G.
270.4 fl. ozs. was separated from the main batch after
fermentation was complete for use in the "no alcohol
REMOVING THE ALCOHOL.
The 270.4 "experimental" ozs. were racked into 4,
2-liter plastic soda bottles. Those bottles were placed
upside-down (on their caps) in a freezer at between 0 and 10 F
for 36 hours. The fluid in the bottles was solid at the end of
By inverting the bottles, the fluid that did not freeze
(including the alcohol) was at the cap-end of the bottle,
making it easier to pour it off. The biggest surprise of this
whole process was that when I opened the cap on the bottles,
they virtually exploded. After the first bottle, and cleaning
the sink, cabinets, walls and ceilings of alcohol sludge, I
opened the remaining three bottles underneath a plastic bucket.
Each one of them exploded. I estimate that 770 ml of the
alcohol sludge (I will call the "extract") was lost on the
walls and down the sink. I did manage to save 950 ml of the
There was an unexpected problem when I removed the 950
ml extract. I had been forewarned that this freezing method
removed a lot of body and hop bitterness (thus the 1# Cara-pils
and 35 IBUs), but no one had mentioned the loss of color. This
was supposed to be a pale ale, and had been the appropriate
color when I froze the beer. But when the extract was removed
the beer remaining frozen in the 2 liter bottles was almost as
clear as ice--no color at all. The extract, on the other hand,
was as dark as a stout. The extract also had a S.G. of 1.039
and smelled like alcohol and HOPS (capitalized on purpose and
So, I was left with the problem of a colorless, no
alcohol beer. This is when I decided to employ the third
method of de-alcoholization--heat. Numerous people had warned
me about the bad effects of heat on the beer for alcohol
removal, and so I decided to heat only the extract. After all,
that's where the alcohol was. After I removed the alcohol from
the extract, I planned to put the extract back in the beer to
give it color again.
Those suggesting heat as an alcohol removal method
instructed that alcohol evaporates at 78-82 C (I did not check
this fact). Therefore, I heated the 950 ml of extract at
174-178 F for 13 minutes, which resulted in 600 ml of extract
at 1.069. After cooling, I returned this extract to the
After going to all this trouble, I did not want to add
any alcohol back into the beer through priming. I was also
concerned about the viability of the yeast after the
freezing/thawing/heating process. So, I put the thawed beer
into a 3 gallon keg and force carbonated the beer for
approximately 2.6 volumes of CO(2). The end result was 244
ozs. (7,222.4 ml) of low alcohol beer.
In Part I, I described my attempt to
make a low alcohol beer by starting with a low gravity beer
and then removing the alcohol by freezing the beer and
pouring off the alcohol. In this part, I will set
out my estimates of how efficient that alcohol removal process
My Disclaimer: I am not a chemist, physicist,
mathemetician, professional brewer, alchemist, botanist, or
floral arranger. However, I am a lawyer and know how
to write a disclaimer. Accordingly, none of the following
theories, theorems, equations, hypotheses, statements, opinions
and conclusions should be relied on. If you need a truly
alcohol-free brew for health or safety reasons, please do not
rely on my (probably flawed) methodology and results. Instead,
buy a tried and tested commercial, non-alcohol beer. The
purpose of this post is the amusement of the homebrewing
collective. If anyone sees an error in any of the following
(and I'm sure there are a few), please point it out. I don't
mind admitting that I struggled greatly with these equations
and the theory underlying them.
The Alcohol Content of the Original Beer.
I started by figuring the alcohol content of the beer
before I did anything unnatural to it. I used the following
formulas (taken from the Summer 1995 Zymurgy):
O.G. 1.031 F.G. 1.012
Thus the beer had a very low alcohol content of
approximately 2.5% even before doing anything to it.
I next computed the volume of actual alcohol in the
beer. The total beer volume was 244 ozs. (7,222.4 ml), and so
I multiplied that number by the percent alcohol by volume to
determine the number of milliliters of alcohol in the beer:
7,222.4 ml beer x .02544752491 = 203.6779104 ml alcohol
Composition of the Extract.
Out of necessity, I made the assumption that the
freezing method removed all of the alcohol in the beer with the
extract, and that no alcohol remained in the frozen beer.
Therefore, all 203.6779104 ml of alcohol were contained in the
I saved 950 ml of the extract and, based on the
beginning and ending volumes of beer, estimate that I lost
approximately 770 ml of the extract down the sink, on the
walls, etc. Therefore, the total volume of the extract was 950
+ 770, or 1,720 ml.
Again, out of necessity I assumed that the percentage
of alcohol in the extract I lost was the same as the percentage
of alcohol in the extract I saved. This does not seem to be an
outrageous assumption to make. Then I computed the volume of
alcohol that was lost with the lost extract:
[770 ml lost extract/1,720 ml total extract volume] x
203.6779104 ml alcohol = 91.1813901199 ml alcohol lost
203.6779104 ml alcohol - 91.1813901199 ml alcohol lost =
112.496520281 ml alcohol in 950 ml saved extract
Specific Gravity of the Extract Without Alcohol.
Next you must compute the specific gravity of the
extract as if there were no alcohol in it. I used the number
.796 as the S.G. of alcohol in this equation:
(extract gravity)(extract volume)=
(SG alcohol)(alcohol volume)+(SG of extract without
alcohol)(alcohol-free extract volume)
1.07164064578=SG of 950 ml extract without alcohol
Adjusting the Specific Gravity for Volume.
The next calculation adjusts the specific gravity of
the extract without alcohol (1.07164064578) for the reduction
in volume of the extract that occurred when it was heated. The
extract volume was reduced from 950 ml to 600 ml. From the
above, though, it was determined that only 837.503479719 ml of
the original extract was not alcohol. Assuming there was a
proportional decrease in the volume of extract that was alcohol
and the volume of extract that was not alcohol, the non-alcohol
portion of the extract would have been reduced from
837.503479719 ml to 528.949566144. [The reality is that the
non-alcohol part of the extract actually evaporated slightly
quicker than the alcohol part. This can be demonstrated through
several equations which I have not included here.]
The specific gravity of the non-alcohol part of the
extract is adjusted for the reduction in volume as follows:
837.503479719 ml (begin volume)/528.949566144 (end volume)
x 1.07164064578 (SG non-alcohol part)
= 1.11343102248 (SG of non-alcohol part of 600 ml extract)
Calculating the Alcohol Content of the Processed Beer.
Finally, taking the results from the foregoing, the new
alcohol content of the beer, after the freezing and heating
processes, is calculated.
[Actual SG of extract]/[SG of extract without alcohol]
= Efficiency Factor
Efficiency Factor x Original Alcohol Vol.=Actual Alcohol Volume
1.069/1.11343102248 = .60829919797 [efficiency factor]
.60829919797 x 112.496520281 ml alcohol = 68.4315430613 ml alc.
The remaining amount of alcohol in the extract, which
is added back to the beer, is 68.4315430613 ml. The total
volume of the beer is 7,222.4 ml. Thus, it is simple to do the
final calculation and figure out the alcohol content of the
beer by volume:
68.4315430613 ml/7,222.4 ml = .0094749035, or approximately 1%
The beer therefore still has about 1% alcohol by volume
because the extraction method was only about 61% efficient.
COMPARISON OF BEERS.
The untreated beer was only slightly darker (maybe 2-3
SRM) than the beer which had been frozen and had alcohol
removed. The untreated beer also had slightly more hoppiness
and a little more body. However, on the whole I can not say
that the alcohol removal process dramatically changed the beer.
While I would certainly prefer a regular pale ale, I found both
the treated and untreated versions of this beer to be very
drinkable, and certainly recognizable as beer.
METHODS OF IMPROVEMENT.
If I were to attempt a no- or low-alcohol beer again,
which, by the way, is a lot of work, I would use this same
method. Freezing the beer, removing the extract, heating only
the extract, and returning the extract to the frozen beer gives
the benefits of alcohol removal without losing all of the body,
hoppiness and color found in the extract.
Improvement is needed primarily on the efficiency of
the heating process to remove alcohol. A longer heating
process is necessary. Through a series of other calculations,
I estimated that to get a beer of this OG/FG to less than .5%
alcohol v/v (the legal definition for a no-alcohol beer),
approximately 90% of the extract would have to be evaporated by
heating. One-half of the volume that evaporates could be
replaced by water without harming the color or flavor of the
I would be very interested in receiving any comments or
suggestions anyone might have.