Originally Posted by JimRausch
Interesting. I always thought that the diacetyl rest was to break down already formed diacetyl. LOve this forum- learn something new every day!Thanks Topher.
Yes, that is indeed the point of the diacetyl rest. Diacetyl is formed by yeast as a byproduct of fermentation. When the active fermentation is over, the yeast are still trying to continue, so they'll start digesting less preferred foods such as maltiose. Then, they'll even go back and start digesting their own waste products (such as diacetyl).
Like I said, I never knew anybody who had any luck getting rid of diacetyl after lagering, or after packaging the beer except by krausening (to get active yeast to clean up the diacetyl). I hope I"m wrong, though, and you can do it.