question about fermentation temp

I'm on my 4th brew. The previous 3 I let ferment in my basement. Room temps were in the mid 60's. I live in the northeast and my basement is starting to get pretty cold, so it's now closer to 60 degrees.

I brewed an IPA on Thursday night (it's Saturday monring now), and I figured I'd let this one ferment upstairs, where room temp is about 70. I used the wyeast 1332 (which says optimum temp is 65-75.)

My questions are: is the room temp of 70 too warm to ferment? And if so, can I move into the basement now (even though the beer seems to be at the height of fermentation right now)? I'm struggling with room temp vs. beer temp... and whether 60 is better than 70...

Any advice? Thanks!

When brewing beers that you like to have with a nice clean, pretty ester free flavor profile, fermenting at the bottom limits of temperature are always better that the upper. The warmer yeast gets the more esters and phenols are created.

Also keep in mind that active fermentation can raise the internal temp of the beer 5-10 degrees at the height of fermentation.

I would lower the temp but keep in mind you will possibly shock the yeast a bit with the lowering of the temperature and they may begin to go dormant on you depending on how quick the temp drops, things may slow down and then you may need to gradually raise the temp to get them going again.

You should consider a swamp cooler set up to maintain steady temps throughout fermentation or some sort of chamber with temp control. Keep in mind yeast don't really mind going from cold to a gradual warm up but the opposite is not very beneficial. Once excessive esters or phenols are produced they may or may not go away and these are formed during the height of fermentation.

The only thing I would add is to get an adhesive strip thermometer for your fermenter so you will know the temp of your fermenting beer.

^ thanks. Going forward I'll certainly look into a swamp cooler setup.

But for this specific batch, let it ride out around 70 degrees room temp? Its on the main floor of our house, so I can't lower the temp much under 70 in the room that it's in. Manly other option would be to move it into the basement, but like you said, I'm afraid it may shock the yeast...

bmac said:

The only thing I would add is to get an adhesive strip thermometer for your fermenter so you will know the temp of your fermenting beer.

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I do have an adhesive strip thermometer on the fermenter right now. Its reading 70. I thought that was more reading the ambient room temp as opposed to the temp inside the fermenter, no?

If it's already actively fermenting away and at high krausen then let it ride because most likely those fruity esters are already present and lowering the temps won't make them go away.

erbo said:

^ thanks. Going forward I'll certainly look into a swamp cooler setup.

But for this specific batch, let it ride out around 70 degrees room temp? Its on the main floor of our house, so I can't lower the temp much under 70 in the room that it's in. Manly other option would be to move it into the basement, but like you said, I'm afraid it may shock the yeast...

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You might as well let this ride where it is. If off flavors are going to be produced it happens in the first 36 to 48 hours of fermentation.
Good luck.

I have a picture of my swamp cooler set up in Photos.

erbo said:

I do have an adhesive strip thermometer on the fermenter right now. Its reading 70. I thought that was more reading the ambient room temp as opposed to the temp inside the fermenter, no?

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The strip thermometers actually give the temp of the liquid inside the fermenter.

Yeah,temp strips give internal temps. I tested mine against my All Temp laser thermometer,& the readings were within about .4 degrees of each other. For many ale yeasts,like US-05,70F will still give a clean flavor. but 64-68F would be better in my experiences.

bmac said:

The strip thermometers actually give the temp of the liquid inside the fermenter.

Click to expand...

Well then maybe I'm not too far off. The wyeast strain says stay between 65-75.. And I'm at 70. I can't imagine the beer will be ruined. Hopefully it comes out ok. Thanks for the advice!

But probably not good to try and start at 60 either. I tied this week and it didn't work. I had cooled the wort to 62 and pitched yeast (S-05) cooled to about the same temp. I sat in a 60 degree basement and checked the temp the next day. The stick on thermometer showed 60 and there was no sign of activity. At 24 hours or so I brought it up stairs and as the temp got to 66 over the next 14 hours it started developing a 1/4 layer of krausen. I then took it back the basement and put a towel around it. It has been maintaining about 64 degrees and is bubbling along.

It never did get any giant krausen but seems to be fermenting.

I am thinking a water bath and an aquarium heater will be the answer for winter.

emp will do fine with US-05. Cooler ferment temps take longer,but are cleaner.
I used it in my robust porter @ 67F,& it took till this morning,the 4th day,to get through initial fermentation. it's bubbling more slowly now,creeping down to FG. So cooler is better,but only to the lower range of that yeasts' sweet spot.