How cold is too cold for a lager

I have my lager in a room that depends on the weather for temperature control. Yesterday it started out warm outside and peaked around 50, today it didn't hit 32. The room was already getting warm yesterday, the fermometer on the carboy said 54, which was still OK, but I figured I better put the carboy outside. I covered it with a cardboard box made out of my daughters science project board from last year "Does Yeast cause Fermentation" (really!) Anyway, I brought it back inside when I got home from work because it was getting colder. The temp in the carboy was 48.

Overnight it was cold, and the inside room has no heat and the temp stayed at 48. Today I get home from work and it is down to 46.

The airlock is bubbling away, but slower than any ale that I've made. Krausen has formed at the top, the yeast has multiplied. I made a 3qt starter and pitched it cold, although not this cold.

Will having it cold impact anything other than fermentation times? Should I warm it back up to around 50-52? I really don't have much control other than opening the inside door to the room it is in, and then I'd worry it would get too warm. I'm trying to get this lager right, my last one didn't come out all that great, too many off flavors. That doesn't mean it went to waste however, I only have 2 bottles left.

50 is about perfect for fermentation. I like to use a water bath, that way it takes much longer for temperature fluctuations to change the temperature in the fermenter. I have my fermenter in a cooler, with a water bath, to moderate the temperature. Can you do something like that, so the temperature doesn't swing from 46-52?

I have otherwise unused garbage cans from the last lager that I made. I used them for lagering last time, putting ice bottles in to keep it down in the low 30s. I could probably rig something up to keep it more steady but I still don't have any other control. At least the forecast is for cold, which is better than warm in this case.

If your beer stops being a liquid and starts being a solid... you've definitely gotten it too cold.

Maybe it is too cold. I took a reading last night after 7 days and it was still at 1.028 or so. It is still going, but very slowly. The krausen is still there, with new white peaks of foam breaking through the brown that settles on top. It has been cold in NY but it won't be so cold on Thursday and I'll let it warm up over 50 so it gets going a bit. I suppose I could open the door to the room and let the house heat get to it a bit.

I tasted the sample and it was pretty good. Still very sweet and yeasty though.

zacster said:

Maybe it is too cold. I took a reading last night after 7 days and it was still at 1.028 or so. It is still going, but very slowly. The krausen is still there, with new white peaks of foam breaking through the brown that settles on top. It has been cold in NY but it won't be so cold on Thursday and I'll let it warm up over 50 so it gets going a bit. I suppose I could open the door to the room and let the house heat get to it a bit.

I tasted the sample and it was pretty good. Still very sweet and yeasty though.

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Patience

You shouldnt even think about taking a gravity reading on a lager at 7 days.
I dont even think about taking one until 14-21 days.
3 weeks in primary is a good time frame to look at.

My last three lagers have fermented in the high 40's due to my basement being so cold and both are fine, they just take longer at cold temps.

Lagers take much longer to ferment when they are in the 40's, but you say there is airlock activity, so it is moving in the right direction! You can't rush a lager.

MA_Brewer said:

Lagers take much longer to ferment when they are in the 40's, but you say there is airlock activity, so it is moving in the right direction! You can't rush a lager.

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NICE AVATAR!

I had an Airedale terrier, great dogs
King of the Terriers

My main fear is I'm going to run out of cold weather. It'll be in the low 50s outside tomorrow, which means the room will heat up. I can put it outside under an inverted garbage can that hasn't otherwise been used, but what if it gets even warmer? I guess I'd have to run out and buy a cooler and use a water bath as Yooper suggested.