I’ve got 5 gallons of porter that has been fermenting in a water bath for 6 days at 70 F with Safale S 04. The outside weather is getting cooler and I could move it into my garage and probably drop the fermentation temp by 3 or 4 degrees. After 60 days at 70 F, will this make any appreciable difference in taste or quality?
Are you referring to ambient or the fermentation temperature? I use S04 pretty regularly and don’t care for it at 68F or above as it seems to get estery with a strange bready character. At this point, 3-4 degrees lower won’t hurt anything.
I don’t see a benefit to moving the beer and see a possible downside if the yeast aren’t finished cleaning up after themselves , e.g., reabsorbing diacetyl. Having said that, I don’t have much experience with S-04.
I work hard to avoid lowering temp until the beer is completed. In my understanding, as fermentation winds down, a drop in temp can cause yeast to quit early.
EDIT - After this many days the fermentation profile is pretty much set, in terms of esters, possible fusels,etc. So lowering won’t do a bit of good and could be a negative in terms of letting the yeast clean up off flavors/aromas, as mentioned.
That is a pretty insignificant drop, but I agree that typically, I seek to go up in temp at the tail end of primary, then drop it by crashing ales and lowering lagers per Brulosopher method. A few degrees like that probably makes little or no difference now.