Diacetyl rest

[Jakeyboi]

Hi everyone

I just kegged my Czech pilsner, it had been fermenting at 12C for two weeks and was down to 1.010 for a couple of days.

I was keen to get it in the kegerator to start carbonation and lagering ASAP.

I had a little taste and was delighted with the overall outcome, but I think there might be a very very slight buttery taste. Knowing I didn’t raise the temp up for a diacetyl rest I’m now a little bit paranoid.

My question is, does the diacetyl rest need to be done whilst the beer is still fermenting, or is it possible for me to simply raise the temp now?

Secondly if I am able to raise the temp now, will it work in the corny keg?

I’m probably going to leave it alone now for a couple of weeks and give it a taste when it’s cold and carbonated. So may not need to do anything if it’s good.

Appreciate your collective wisdom

Jake

 

[An Ankoù]

Czech Pilsner such as Pilsner Urquell has a bit of diacetyl anyway, so nothing to be paranoid about.
My understanding of the diacetyl rest is that it should be done on the yeast cake by raising the temperature a few degrees for three or four days. Whether there'll be enough yeast left in the beer to do this quickly, now that you've racked it, I don't know. Carbonation shouldn't be an issue, but you'll need to bring it into the warm.
As you said you had tasted it and it was delightful, you could just make a note in your records to allow for a diacetyl rest next time, if you can still taste it when it's ready.