Infection

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Michael Erwin
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Infection

Post by Michael Erwin » Sun Mar 14, 2010 10:01 pm

After 2.5 years of brewing, I can finally say with direct experience, I know what an infection smells, tastes, and acts like! I had a pilsner in 12oz bottles, which was decent, actually pretty refreshing, just after it was carbonated. But now, six weeks later... well...

About two weeks ago, I tried one, and thought, that doesn't taste very good. Not extremely bad, just a little off, that's all. But off enough to think, this is no good. So, I take all the bottles out of my storage area, and I open one.

Granted, the bottles were stored at about 60F, so not extremely cold. But, oh, geez, do you recall building a volcano in grade school, using vinegar and baking soda, how it spewed out foam and ran down the sides? This bottle did that. Within about 5 seconds of popping the cap, the thing was spewing foam. Yikes!

So, I pulled all of the bottles out, opened them one by one, and sure enough, every single one became its own private little volcano. Luckily, I was close to the kitchen sink.

Live and learn. I'm not at all sure what happened to infect the entire batch. I think the yeast starter may have been the culprit, only b/c the odor of the beer that gave its bad flavor, if I remember correctly, was in the starter.

C'est la vie.
Michael Erwin
------------
Some people say the glass is half empty.
Some say it's half full.
I just want to know who's drinking my damn beer!

psfred
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Re: Infection

Post by psfred » Tue Mar 16, 2010 2:19 pm

Yup, been there done that.

There are several ways to contaminate your beer you may not be thinking of.

What used to get me into trouble was adjusting the volume up with "treated" water -- I don't do that any more, just take whatever volume I get. I had surface water, and hence soil bacteria, getting into my well that I didn't know about. Nasty.

Basement dust, outdoors dust, poorly sanitized tubing or containers, and yes, contaminated yeast starters, can all do you in.

Most of the bacteria that cause trouble are fairly slow growing, and you will get normal behavior until the beer has been bottled. Once in a while you will get a wild yeast in a batch that causes excessive foaming during primary fermentation, but usually the beer seems fine until it's been sitting a month or more.

I would keep some dry yeast on hand if you use starters, that way you can use that instead of a funky starter -- your beer is going to smell like your yeast starter does, pretty much, and if it's bad in the starter, use some other yeast!

Peter

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