ericbw
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- Dec 11, 2012
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I brewed the following and let it ferment for 4 weeks. Yesterday we bottled. There were a few bubbles on top of the finished beer, but minimal. The gravity was at 1.008 (lower than I wanted) from an OG of 1.053. It was a little cloudier than the last batch, but it's a wheat, so that's ok for the style. Looked/smelled/tasted pretty good.
I saved a quart of the yeast slurry in a sterilized mason jar.
The concern: I set the yeast on the counter to settle, and as it settled, I noticed bubbles forming at the top. Periodically last night, I had to release some pressure from the mason jar.
This morning, it was settling like it should to about a pint of thick yeast and the rest beer on top. I cracked the lid again to release the pressure. About 15 minutes later, I noticed that the yeast was back in solution and bubbling at the top. The yeast slurry smells a little funky, not yeasty, but almost vinegary.
The bottled beer looks normal (no foam or bubbles in the bottles, thin layer of sediment on the bottom already forming).
The smell makes me think vinegar, but the fact that the yeast had settled down in the fermenter makes me think IF it got infected, it got infected in the jar. In other words, I suspect the beer is fine, but the yeast is now contaminated.
A) Could the fermentation just not be finished after 4 weeks? The gravity was low, so how much more could it go anyway?
B) Could acetobacter live through a 5 minute boil for sterilization, followed by Star San just before collecting the yeast? I can't remember what was in the jar last time we used it, but possibly something naturally pickled.
Anyone have any ideas?
The recipe:
4 lb wheat malt
3 pounds 2-row
.5 C10L
.5 oz Willamette @ 60
.75 oz Saaz @ 15
Yeast: a starter of second generation US-05 slurry. (I have used this same generation for another batch with good results.)
Fermented 4 weeks at about 65 degrees with occasional rousing. With most smaller batches, I tend to rouse more (it's easier), but I also have a tendency to open the fermenter once or twice for a look/smell. This time, I never opened it, but I also roused less.
I saved a quart of the yeast slurry in a sterilized mason jar.
The concern: I set the yeast on the counter to settle, and as it settled, I noticed bubbles forming at the top. Periodically last night, I had to release some pressure from the mason jar.
This morning, it was settling like it should to about a pint of thick yeast and the rest beer on top. I cracked the lid again to release the pressure. About 15 minutes later, I noticed that the yeast was back in solution and bubbling at the top. The yeast slurry smells a little funky, not yeasty, but almost vinegary.
The bottled beer looks normal (no foam or bubbles in the bottles, thin layer of sediment on the bottom already forming).
The smell makes me think vinegar, but the fact that the yeast had settled down in the fermenter makes me think IF it got infected, it got infected in the jar. In other words, I suspect the beer is fine, but the yeast is now contaminated.
A) Could the fermentation just not be finished after 4 weeks? The gravity was low, so how much more could it go anyway?
B) Could acetobacter live through a 5 minute boil for sterilization, followed by Star San just before collecting the yeast? I can't remember what was in the jar last time we used it, but possibly something naturally pickled.
Anyone have any ideas?
The recipe:
4 lb wheat malt
3 pounds 2-row
.5 C10L
.5 oz Willamette @ 60
.75 oz Saaz @ 15
Yeast: a starter of second generation US-05 slurry. (I have used this same generation for another batch with good results.)
Fermented 4 weeks at about 65 degrees with occasional rousing. With most smaller batches, I tend to rouse more (it's easier), but I also have a tendency to open the fermenter once or twice for a look/smell. This time, I never opened it, but I also roused less.
