Removing Diacetyl...

[Malnourished]

OK I'm after a little guidance here. I brewed a pils (with W-34/70) a while back, and whilst I didn't do a diacetyl rest I left it in primary for almost three weeks and tasted it at several stages along the way and never noticed any diacetyl. Of course now, after lagering and kegging, it tastes decidedly of diacetyl.

I figure my options are as follows:
1. Bubble CO2 through the beer to scrub out some of the diacetyl.
2. Warm the keg up and leave it for a couple of weeks in the hope that whatever yeast is left in there will clean it up.
3. Warm up the keg and do some krausening of sorts with some freshly fermenting wort.

Anybody have some experience with this? Are any of these likely to work? I'm leaning towards option number three at this point.

 

[jayse]

I don't think warming the keg up would work because what yeast is left there has more than likely cleaned it up the best it can and there was more diacetyl than it could take up. Iam not sure if 'number 3' works but it stands to perfect reason fresh yeast would have much better chance of consuming the diacetyl.
Because it has developed more over time rather than developed early on and slowly been reabsorbed it would suggest a infection produced the diacetyl. But it could be as the beer has aged the other flavours have become more delicate and not so green, the remaining diacetyl is now more pronounced, but if it was produced by the yeast during the ferment it would have been there all along the the lagering period.
I made liquid microwave popcorn once! nasty stuff!
Jayse

 

[Malnourished]

I'm reasonably sure it's not an infection, but I guess you can never know for sure. I had a cold for quite a while there so maybe I just wasn't picking up the diacetyl amongst all the other green flavours, like you say.

I thought option number two might work because the remaining yeast had never had a chance to operate at warmer (probably 16-18C) temps. In any case it's currently going through option two waiting for me to get some yeast ready for option three.

 

[JasonY]

I had an ale that was particulary buttery, decided I didn't like it so basically warmed the keg degassing as it warmed. Once it was back to room temp I chucked some lager yeast in there (500ml starter) and left it for a week - it cleaned it up nicely. Didn't really taste like an ale but is was much more drinkable than before.

I would try option 3.