Diacetyl

[RndyIamTheLqr]

Pretty sure I have been fermenting at way too high of a temp. Some of my beers have had a butter scotch taste. What should be a good ambient temp to keep my beer within the limits?

 

[honkeypot]

Check the yeast manufacturer websites for specific temperature ranges but generally speaking most ales ferment around 65 degrees.

 

[honkeypot]

Also if you start kegging or bottling immediately after you get stable gravities you'll prevent the yeast from metabolizing byproducts of fermentation like diacetyl. Give them time to chew that stuff up.

 

[BroStefan]

It really depends on the yeast but in general pitch at the low end of the strains temp range and hold it there until past high krausen and then if you can raise the temp a few degrees f so the yeast finishes and cleans up.

 

[dhop]

I recently made the switch to a temperature controlled fermenter (was fermenting somewhere between 70-75F, now 65 +/-1F) and found the bulk of the diacetyl taste had dissipated. This was with Safale US-05 and S-04.

However, there were still subtle hints of that off flavoring, which turned out to be due to Chlorine in the brew water. So if things are still a little off after you get the temperature in check, look into the potential of chlorine in your water and get some campden tablets/ charcoal filters as an easy fix.