It's there a point to extending a diacetyl rest after FG is reached?

[Froyd]

Started my D-rest a little later than I would have liked. Maybe 8% from target FG. After 48 hours, my hydrometer reading showed that the beer had reached the target FG of 1.010, but I could still detect some diacetyl so I decided to let the beer sit at 68 F for another couple of days. Taste improved, no diacetyl and gravity still at 1.010.

My understanding of fermentation is very basic, but I would have assumed that after final gravity is reached there is very little yeast activity going on... So what's cleaning up my diacetyl?

 

[FunkedOut]

The yeast will prefer to consume the sugars than diacetyl.
Once the sugars are gone, any hungry yeasts still awake will eat what’s still around, including diacetyl.
The idea behind starting the d-rest before hitting FG is to ensure there are plenty of active yeast cells when the sugar runs out.

 

[couchsending]

Do a forced diacetyl test, then you’ll know for sure. It kind of depends on the yeast. Personally I’d wait until 24 hours after FG at least, waiting is only going to make your beer better. Not waiting however could make it worse.

 

[Froyd]

The yeast will prefer to consume the sugars than diacetyl.
Once the sugars are gone, any hungry yeasts still awake will eat what’s still around, including diacetyl.
The idea behind starting the d-rest before hitting FG is to ensure there are plenty of active yeast cells when the sugar runs out.

Thanks, FunkedOut. Makes sense.