The Mid-Columbia Zymurgy Association held their Fall Megabrew last month, where (thanks to Ice Harbor Brewing Company) the club got to brew on a large scale commercial system. They made hundreds of gallons of wort, and each club member was able to take home a carboy to ferment themselves.
This particular monster was a Weizenbock, which I was not all that excited about - so, since the holidays are coming up, I decided to make a winter warmer out of it. I had a pilsner that had just finished fermenting, so I figured I would use the lager yeast from there and just dump my five gallons of Weizenbock on top of it - and it fermented down to 1.015 from 1.072.
I really wanted to experiment with this one, so I made a tincture consisting of 8 ounces of vodka with cinnamon, ginger, clove, and allspice. I let that sit for a week while the beer was fermenting, and once it was done, I dumped the tincture into a keg along with the fresh Weizenbock.
About this time, I caught a segment on The Session that covered techniques for making eis beer. Basically, it amounts to partially freezing your beer to remove a portion of the water, which will intensify the alcohol content, since alcohol's freezing temperature is -114 degrees Fahrenheit. Doc suggested putting a corny keg in the freezer for four days to let the ice crystals form, and then, when shaken, one can hear the ice sloshing around in the keg like a big beer Slurpee. The one caveat: do not let it freeze completely solid!
I thought this all sounded like a fantastic idea, so I contacted my local butcher, who was kind enough to let me throw my keg into his large meat locker. In it went on Tuesday evening, and that Thursday was Thanksgiving, which meant Friday was the earliest I could retrieve my keg. When I did finally show up at 9:00am on Friday, my keg was frozen solid. No sloshing sounds like Doc had suggested to listen for. Four days my ass, Doc. Perhaps home freezers do not get as cold as a commercial freezers?
So into my kegerator it went (at 45 degrees) for about two days, and by Sunday, I felt it slosh around enough to transfer the intensified beer out of the ice and into another keg via my handy dandy transfer hose, which uses CO2 to push the liquid from one keg to another.
In the end, I created a deliciously complex, slightly spiced, boozy, port-like Weizen-Eisbock that is strong as @#$%. Thanks to Doc for inspiring me to experiment and try this 'eis-keg' technique, but he is a lying sack and he was almost responsible for damaging thousands of dollars worth of meat from my ruptured keg. Alas - the resilience of corny kegs never ceases to amaze me.