Is temperature change detrimental to a yeast’s behavior? If so, by how much and what can be expected?
I am considering placing a fermenter in my upstairs closet, or in the attic. The attic is 50 degrees right now, but will vary by +/- 10 degrees through the day. It’s a slow temp variation over a 24 hour period.
If there is 6 gallons with W-34/70 in the attic, how will the yeast behave? Will the yeast be “shocked” with this environment? Experience has shown that this strain will remain active into the mid to upper 30’s.
We have three chest freezers, temp controlled for this purpose. But as usual, they are all filled with 30 gallons of beer. Looking for another avenue of fermenting a lager outside of the freezer. And without spending any more $$$.
W-34/70 performs well at any temperature, it is a very forgiving yeast. I think it will ferment just fine with 10-degree swings. To keep the temperature even more constant, you could either wrap the fermenter in a warm blanket, or set the fermenter into a tub for a water bath as the extra thermal mass will dampen any temperature swings.
Water has a very high specific heat; it absorbs and gives off heat very slowly. The temp of the beer will be far less variable than ambient temp. Putting the fermenter in your attic will work fine.
My fermenting fridge is dying so I’m interested in this as well. I just kegged a lager with 34/70 ( normally use liquid strains ) which I had to ferment between 12-14c as it just wouldn’t come down any further. Samples are quite nice.
50f in your attic? I drove to work this morning at 5:40 am and it was already 88f haha
Think I’ll give it a shot, in the attic!
Of course, my closet which leads straight to the attic is a constant 60 degrees. It’s a spare upstairs bedroom, so most of the time we do not have the heat on there.
Fermentis says the 34/70 will work anywhere from 50 to 70 degrees.
Temperature fluctuations can make yeast produce more esters - I’ve seen a paper where a ?6F drop in temperature led to almost as much ester production as a ?6F increase in temperature - but I’d guess that 34/70 is robust enough that you should be OK. Something to bear in mind with eg British strains though.
I assume that was in a commercial brewery? Do you think that the difference in volume and fermenter geometry whejj you get to homebrew might alter that result?
It was an academic paper so I guess it would have either been at lab scale (ie <1 litre bottles) or a nano trial scale (say 100 litres), I can’t remember - they were trying various temperature profiles. It wasn’t a recent paper.
My attic is no longer under consideration. This morning the OAT is 28 degrees. Attic temp is 38 degrees.
Closets holding steady at 58. Upstairs, north side, with the heat off. Perfect!
I’m back to experimenting again, my other half has taken over the former junk room on the north side of the house which kept a really nice steady temperature in the mid-teens °C (so high 50s°F?), for the pathetic excuse of WFH. So now she’s keeping it at “her” comfortable temperature which is about 10 degrees more than my Scots blood could stand. She really needs to sort her priorities out…