Post Fermentation Freezing

silverspoons · Joined: 21 Dec 2010 Posts: 555 Location: Webster NY

OK i'll be the first to jump in to this thread..

After reading several articles and seeing videos about Brew Dog ( www.brewdog.com ) , that radical scottish brewery with insanely high alcohol levels ( some to 42% ), i decided to experiment.

a little background... Brewdog's brewery is located right next to a commercial ice cream factory and for some reason ( beats me ) they freeze and thaw their beer several times post fermentation and pre-bottling. its said to increase alcohol content.

i started last summer with a simple and very good cream ale recipe. brewed a 5 gal batch, first fermenter for one week, then second fermenter for a second week as usual.. then the fun. when it was time to bottle i split the batch in half, priming and bottling 2 1/2 gallons and sticking it in the basement ( about 68 degrees F).. the other 2 1/2 gallons were split between 3 one gallon jugs ( leaving a little room for expansion) and stuck in the freezer for 5 days.. frozen! then brought out and thawed and returned to room temp for 3 days and repeated this freeze / thaw process 3 times.

after about three weeks, i primed and bottled it and put in the basement with the other half of the batch.. One month later a couple bottles of each were chilled and opened for comparison. (the tasting actually took place at the bar next to my business at a friday afternoon happy hour, for some "professional" opinions. )

first .. the frozen was much cleared and crisp. ( i assume some sort of Lagering took place here). and there was a distinct aroma of alcohol and the beer was much stronger. both were excellent but we ended up with two very different beers from the same batch AFTER fermentation. i'm not sure of the chemistry here, if anyone can lend a suggestion it would be appreciated..

Oh! there a full 5 gallon batch frozen in my garage right now, i knew there would something good about brewing in the winter.

**kal** · Posted: Tue Jan 11, 2011 9:29 pm Post subject: Re: Post Fermentation Freezing

silverspoons · Joined: 21 Dec 2010 Posts: 555 Location: Webster NY

Thanks Kal, i'm familiar with the fractional freezing process and i know that how brewdog gets those crazy levels. in my "experiment though, there was no separation, but clearly two different results in flavor, appearance and aroma..

**kal** · Posted: Tue Jan 11, 2011 11:04 pm Post subject:

Sorry - I guess I read your post too fast... I thought you said there was more alcohol after freezing/thawing.

Kal

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

I froze my beer by accident this winter. It get's cold here - -20C (-4F) is fairly typical. I left a couple of kegs of beer outside, and they froze. I let them defrost a little, and then poured a pint. It was almost undrinkable - really bitter and quite strong alcohol. I can understand the alcohol, but I wonder why so bitter? When completely thawed, the beer was back to it's old self - a hobgoblin clone.

silverspoons · Joined: 21 Dec 2010 Posts: 555 Location: Webster NY

crush.. when your beer returned to " normal" did you notice any physical differences? like i said i split a 5 gal batch in half and i had two very different beer.

crush · Joined: 28 Dec 2010 Posts: 706 Location: Telemark, Norway

It's hard to say, since I didn't have two batches to compare, so I don't know how it would have tasted without being frozen, and also it's all of 6 weeks ago, which puts it at the fringes of my recollective abilities Wink

The beer aged a bit during/after it's freeze, but then this was kegged fairly early. (Benefits from a good 4 weeks aging in the keg) so it would have probably done this anyway. It was only frozen for a day or so.

From what I remember, there was no drastic change, maybe a little more alcohol warmth. The keg lost pressure, so I had to recarb.

Feurhund · Joined: 01 Feb 2011 Posts: 89

Interesting side note. In the United Statesnit is illegal to distill spirits at home. The fractional distilling that is used in making " Ice Beer " is actually considered distilling and holds up to 5 years in prison and a $50,000 fine! Unbelievable.

silverspoons · Joined: 21 Dec 2010 Posts: 555 Location: Webster NY

No Really Sir! i never thought of freezing beer at home...Sir... Honest!