How to Brew Low Alcohol Beer at Home -- Part 1

In 1995 I asked homebrewers on the Internet for information on making alcohol-free beer. 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. Part 1 of this article summarizes the responses I received and tells of my experience with making low alcohol beer. Part 2 provides some of the science, a comparison between methods and several suggestions for improving the process and the product.

THE RESPONSES

I received 24 responses to my post for information on brewing low alcohol beer:

• 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 possibility;
• 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.

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 noted were:

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 undesirable;
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 gradient.

THE PLAN

Armed with this information, I decided to merge two of the most popular concepts together by brewing 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 than suggested.

The recipe I used was for a pale ale-type beer, and consisted of the following:

3# Domestic Malted Barley

1.75# Munich Malt

1.25# Cara-pils

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. was 1.012. 270.4 fl. ozs. was separated from the main batch after fermentation was complete for use in the "no alcohol experiment".

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 that period.

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 extract.

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 for effect).

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 melting beer.

CARBONATION

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.