controlling ferm temps because i can, but question....

Using a cheap swamp cooler for my Brandon O Graff. Temp for fermentation was around 68 f last night. I added a frozen gallon of ice before bed, just to make the fermentation happen at the bottom end of ale production temps. Woke up this morning to find out its still bubbling, Krausen gone, and the temp at 62 f. I suspect it dipped below ale temps last night. Is this okay?

 

beers I fermented this past winter were kept mostly at 62°. all have turned out awesome

but it really depends on the yeast and its optimum temperature range

one batch was a Maibock that was fermented @62 with WLP060, optimum temp range is 68-72°. that one turned out really well and did OK in brew club competition. no one figured out it was an ale, even the brew club president said it was a very good example of the style

 

Congrats, man!

I'm using Safale S-04 yeast (they were out of Nottingham), which Northern Brewer claims has an optimum temperature of 64 F to 75 F. On a side note, 75 seems a little high... no?

It's still chugging away, so I suspect that no real damage was done.

 

I would be concerned that the big swing in temperature may impact the overall flavor, but I wouldnt be concerned about the yeast being unable to perform the rest of fermentation appropriately. Keep it as consistent as possible at either temp and your beer will be good. Jumping around by 6 or so degrees every day is not good.