US-05 done in a night?

So I brewed this recipe yesterday afternoon and pitched around 5 pm. I threw a whole packet of US-05 into ~2.25 gallons of 1.040 wort. (If you didn't read the thread, this is just an efficiency test batch/drinkable starter). I went down to the basement this morning and there was no airlock pressure at all. I cracked the lid and there was a full krausen. Could it have finished overnight? I'll probably bring it upstairs to make sure it finishes (basement at 58 ambient and apartment ~63 ambient).

If there is a full krausen it is obviously not finished. I would suspect an air leak if you had no airlock activity.

It didn't finish at 58 in 12-15 hours. It's just getting started.

I know its not ready to bottle finished, I just meant the bulk of fermentation. I know that's a lot of yeast to pitch, and I was just wondering if they'd already gotten through most of a pretty weak wort. When does the krausen usually fall? Immediately when fermentation is done? When it's completely done or after the initial 'explosive' stages are complete?

There might be an air leak, but the lid has a rubber gasket, and when I put pressure on the bucket the airlock shows that. Maybe the temperature drop and subsequent decrease in pressure is counteracting the pressure from CO2 production.

I have confirmed there is an air leak--after pushing the lid down, the airlock pressure would equalize. I always ferment in buckets and never peek, so I'm not sure when the various stages of krausen, etc. occur in fermentation. I did see that there are some thing floating around and it's still fermenting. Airlock activity is not a sign of fermentation and all that, I know, but had to ask anyway.

tennesseean_87 said:

I have confirmed there is an air leak--after pushing the lid down, the airlock pressure would equalize. I always ferment in buckets and never peek, so I'm not sure when the various stages of krausen, etc. occur in fermentation. I did see that there are some thing floating around and it's still fermenting. Airlock activity is not a sign of fermentation and all that, I know, but had to ask anyway.

Click to expand...

Good not to peek much. Then you are less likely to post a "Is this infected?" thread.

Let's hope the batch turns out well.

Safale recommends fermentation temps of 59-75F for US-05, so you're really at the low end of the range. I usually target 64F...

Aren't those the temps of the liquid, not the ambient temps? I have read and observed that active fermentation will increase the temperature of the wort/beer 5 degrees or more, in which case the fermentation temp is right where it needs to be.

You're correct, I hadn't noticed that you said ambient.

It definitely wasn't done--it cracked the lid open and made a wee mess. There was not enough head space since I didn't get the boil-off I had calculated. I didn't think it'd be an issue with 1.04 wort at 58* ambient, and thought that sort of thing usually happened before 2-3 days into fermentation. I learn new stuff all the time.