Monday, October 25, 2010

Krausen? I barely even know 'em!

So last week (Tuesday exactly), I decided to do a spontaneous brew session. I hopped on Beersmith and sat down with my handy guide "Designing Great Beers" and charts in the back of "Clone Brews" and start drafting up a beer. I want something with kick, balls. Something that will grow some hair on your chest. Not quite a barleywine, however. After about a half hour of fiddling with numbers and ingredients I came up with ATOTB #04: High Octane Imperial Stout.

Brewing went great, couldn't have gone better. My mash tun was full to the top with grain. That morning i was fiddling with brewing efficiencies in my program, so I didn't hit my intended OG which would have yielded me 12% ABV. However I'm on track to get a beer running around 9% ABV. This is my first "big beer." A big beer refers to a beer with a high alcohol by volume. I didn't know what I was in for. Yeast was pitched around 3pm.

The next morning I go about my normal routine. Wake up, let the dogs out, sit at the computer and check my daily comics. From the closet I hear a whistle, kinda like your leaky pool float. I had decided to use my fermentation bucket over the carboy, because I knew the fermentation would be vigorous. Well. Vigorous is an understatement. I open the door to the closet and the airlock is chuck full with dark chocolate brown krausen, blocking the air holes. The lid of the bucket has bulged out and looked like the dome at Tropicana Field. I popped off the lid of the airlock and foam begins flowing out like a middle school kid's science fair volcano. I was on my way to my parents that day, so I didn't have much time to attend to it. I placed it out on the back porch to go through the motions. I come back the end of the day and I've got a stream of fermented beer going across the deck. Finally I spray off the bucket, replace the airlock, and it continued bubbling away for the next few days.

But what the hell is Krausen? Krausen is a thick layer of foam that develops on the top of the beer in the primary stages of fermentation. The foam itself majorly contains many by-products of the fermentation, including dead yeast cells, hop resins, tannins from the grain, and proteins. It also majorly contains fusel oils, which are direct by-products of the fermentation in the beer. Fusel oils are higher-order alcohols (alcohols with more than two carbon atoms) and are off flavors to a beer. They are bitter, nasty and contribute to hangovers (down with fusel!!). Fusel actually means "bad liquor" in German. There are a few different schools of though on how to deal with krausen, mainly two opposing sides. One side says get rid of it, and the other says don't worry about it. I'm thinking that one side is the paranoid chemists, biologists, and school teachers (you know the ones; they're the main market for anti-viral tissues and hand sanitizers) who say remove the krausen, because they dont want it to fall back into their beer and produce off flavors. But the people who run the percentages and odds (engineers, accountants, and insurance risk assessors), leave the krausen be because it is in fact a very small portion of the fermenting beer, and you're more likely to contaminate your beer than improve it.

If you can't tell, I leave the krausen be.

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