Help! Fermentus Interruptus

[pus rocket]

I've brewed a batch of SNP Clone. It was fermenting well at about 65-66 degrees in a temp controlled cabinet until we were hit with a big storm 7 days after I had pitched. The power went out for 2 days and I am left with a batch of mostly-fermented beer at 54 degrees.

I'm pretty sure that it was still fermenting slowly when the power went out. Do I slowly edge the temperature back up to 65, or do I just stop the fermentation and let it sit at 50-54 degrees for a while, then keg it and drink it??

[DannyW]

What's your gravity? How does it taste? It might be done and ready to keg/bottle.

[Bugeater]

At 7 days, basic fermentation was probably pretty close to done. However the yeast most likely haven't had the time (or energy due to the low temperature) to clean up the fermentation byproducts they produced during that 7 days. Once they finish digesting the fermentable sugars, they begin digesting the esters they had produced. This process is what will give you a clean tasting beer.

I would warm the beer back up a little, 65-70 degrees and let it sit another 10 days to 2 weeks. This will clean up the beer and help make sure fermentation is indeed complete (and avoid bottle bombs). Don't worry about the higher temperatures creating off tastes, most of that happens early on during fermentation.

Wayne
Bugeater Brewing Company

[Lufah]

Check your gravity and if it's close I would leave it. If not I would warm it back up.

[Surgeon General]

I'd agree with Bug here and advise you to warm it up regardless of if it's reached terminal gravity or not. Give it two weeks at 65-70 and proceed.

[pus rocket]

Thanks for your replies. My questions stemmed from the fact that I know the fermentation wasn't complete when the temperature dropped and it all stopped. I'll go with heating it and leaving it until next week or so.

And eventually I'll buy a generator, since the power goes out every time we get a halfway decent storm!

I'm not too excited about checking my terminal gravity and then possibly leaving it because I'm pretty paranoid about infection. That's why I've suddenly moved a refractometer to the top of my wish list.