Fermentation stuck? US05 ale got too cold on first night.

byronyasgur · Nov 19, 2016

I pitched a packet of US05 into an ale last night and put it where I successfully fermented my last beers, but the room had gotten really cold overnight and when I checked it this morning it was down to 50 F with no airlock activity. I moved it to a warm room to bring up the temp and the temp is now at 65 but still no sign of anything happening. I shook the fermenter to rouse the yeast but no joy. What should I do? I'm thinking of waiting till tomorrow but I do have some us05 I could pitch more in - really I don't know.
Also wondering there was obviously some fermentation at some point as there was the beginnings of a Krausen but since I shook the fermenter this has gone - will this make any difference?

JonW · Nov 19, 2016

Yeah, 50 is a bit low for US05, but 65 will be fine. The mass of the wort will take a while to warm up to the ambient temp. Keep rousing it and give it about 48 hours. It can take it a while to get activity back.

day_trippr · Nov 19, 2016

Agreed, the yeast are simply groggy from The Big Chill, give them time to revive...

Cheers!

skraeling · Nov 19, 2016

Doing the holiday ale with us05 at 64 right now actually.

kh54s10 · Nov 19, 2016

Give it at least a couple of days at 65 (wort temperature) before you do anything. At 50 the yeast went dormant. Even back at 65 I would expect a longer than normal lag time now.

I doubt you have anything to worry about.