Originally Posted by passedpawn
Good question, not sure, but 150F is probably where they work the fastest. At fermentation temps they probably still work but very slowly. I've used AE and it does work but it takes a week or so to convert sugars and ferment out. Do a search for "Escape from Stuck Fermentation Mountain" and you'll find my thread.
If you mashed for a week at room temp you would have a very sour beer.
I just read about your experience with it. It's here
if anyone else is interested.
Sounds like heat (in a mash) might just drives the reaction faster if it took collectively 6 days to drop your beer from 1.030 to 1.012 after adding the AE.