[ChristineNH]

So, im trying my first batch.  I have my keg fermenting in my bedroom.  My wife likes to have the air and heat off at night with the windows open during the day.  I have told her the Temps need to be constant.  Yesterday morning the house was 58°.  Today the house is 58° and the bedroom is 62°.  Layer on today it warm up to 70° in the house. The beer is 7 days into fermentation.  Is it ruined?  I'm not happy with my girl.

[dmtaylor]

It depends on the yeast, but 99% of the time I would say fluctuations like this are just fine.  Some of the Belgian yeast strains are more finicky and might stall when they cool down.  But most other yeasts don't care and will just keep on chugging.  I think you're fine.  If you are concerned, if you place the fermenter into a tub then fill it with water, the water will slow down the temperature changes inside of the fermenter.  But this is probably overkill in my opinion.  Or you could also simply wrap it in a blanket.

Welcome to the hobby!!

[ChristineNH]

Thanks.  I dont have an extra tub, but I do have an extra aquarium heater and a big storage bucket.

[dmtaylor]

No need to add any heat, unless making a Belgian.  The big bucket might help though.  Or a blanket. 

[ChristineNH]

So just fill a bucket with water and drop it in?  Let the water sit for a bit to get to room temp?

[dmtaylor]

So just fill a bucket with water and drop it in?  Let the water sit for a bit to get to room temp?

Well don't overflow the bucket!  Put the fermenter in first, then pour water into the bucket until the liquid levels are approximately equal in the bucket and the fermenter.  The temperature of the water isn't terribly important as it will all even out in a few hours regardless.

[goose]

My recent batch of Amarillo IPA had a temperture fluctuation when the breaker controlling the compressor in my walk-in cooler tripped, most likely due to the heat genereated in the room where the cooler is located.  It was off overnight with the evaporator still running on a separate circuit.  The beer was in the fermenter for almost 6 days when this happened and the temp got to about 80 degrees in the cooler (insert appropriate swear word here).  Since most of the fermentation was done by this time, I tasted no off flavors in the beer when I transferred and dry hopped it yesterday.  Yeast was a re-pitch of 1056.  So you will be OK.

Yes, temperature control is important, especially during the first couple days of fermentation when most of the esters can be formed.  But toward the end of the fermentation it is not as critical.

[BrewBama]

Another trick is to put a t shirt over the fermenter so it will wick the water in the tub and point a fan towards it to cause evaporative cooling (aka make a swamp cooler).