Oh the smell of butter.

[jgourd]

Brewed a Czech pilsner on 1/31. Everything looked good, hit all my temps and marks. Pitched White Labs 802 @58F (it was cold outside and my tap water was reflecting that). Fermented at ambient temps (64-68F) for a few days until active fermentation was noticeable. Moved to 50F on 2/3. Diacetyl rest on 2/13 at ambient temps again (64-69F). I think I waited a bit too long before the rest; I didn't see much fermentation after that. In any event, racked to secondary on 2/21 (1.013 SG) which is almost the target (1.010). I snuck a taste and the first thing I smell is butter. I thought I had a dirty flask, but nope. I did taste some butter, but the aroma overpowered the flavor. In any event, I hope it works itself out. It's now lagering at 31F, and I plan to leave it there for 3-4 weeks. Then I'll bottle and leave at ambient temps for a few weeks until carbonated; then back to the cold.

 

[MachineShopBrewing]

Sorry to say, but the diacetyl will not go away with lagering. A good way to avoid that in the future is to pitch at 45-46 deg and let rise to 50F, then hold at 50F for 3-4 weeks. There is no need for a diacetyl rest if you do it this way. I just did a German Pils that way and had no diacetyl or acetaldehyde. Unless you like the beer with the buttery flavor, I wouldn't waste your time and just dump it now. I had a couple batches at first that I had to do that to until I started pitching my lagers cold. Also, did you make a big starter for the lager yeast?

 

[jgourd]

Sorry to say, but the diacetyl will not go away with lagering. A good way to avoid that in the future is to pitch at 45-46 deg and let rise to 50F, then hold at 50F for 3-4 weeks. There is no need for a diacetyl rest if you do it this way. I just did a German Pils that way and had no diacetyl or acetaldehyde. Unless you like the beer with the buttery flavor, I wouldn't waste your time and just dump it now. I had a couple batches at first that I had to do that to until I started pitching my lagers cold. Also, did you make a big starter for the lager yeast?

I did not do a starter for this one. Should I have?

 

[menschmaschine]

I did not do a starter for this one. Should I have?

Yes, lagers require a lot more yeast than ales. Even an ale would typically require a starter for a White Labs vial for a good pitch rate. A 3 or 4 quart starter would have been standard for your pils. So, between the low pitch rate and the higher starting temps, there's the reason for your diacetyl.

Diacetyl can reduce with lagering depending on the concentration of diacetyl in the beer. A better thing to do would be krausening the beer in secondary with actively fermenting wort. That should clean up your diacetyl.

 

[homebrewer_99]

I had two ales get diacytl. Both were speed brew experiments.

It is caused when you take the brew off the yeast too soon before it cleans up after itself.

I just added more yeast and let them ferment out again at room temp and it was all cleared up.

Remember to bring the brew up to room temperture for that diacytl rest.

 

[MachineShopBrewing]

Remember to bring the brew up to room temperture for that diacytl rest.

If you pitch your yeast at 45 for a lager and ferment at 50 for 3-4 weeks you will not have to do a diacetyl rest. This will give you a much cleaner tasting beer also. This is the way I do my lagers now and have had great results. By pitching cooler you reduce the diacetyl forming compounds in the beer from the start, so there is no need to raise the temp to room temp.

I did not do a starter for this one. Should I have?

You should check out the pitching rate calculator http://www.mrmalty.com/


There is also some great info on yeast starters.

 

[jgourd]

What do you guys think about just whipping up a 2L or so yeast starter (extra light DME and 1 vial of White Labs 802 lager yeast), letting it get to high krausen, and pitching that in the secondary? I'd then let it sit there for a month at lagering temps until bottling time.

 

[MachineShopBrewing]

What do you guys think about just whipping up a 2L or so yeast starter (extra light DME and 1 vial of White Labs 802 lager yeast), letting it get to high krausen, and pitching that in the secondary? I'd then let it sit there for a month at lagering temps until bottling time.

You will have to bring the temps back up to 50F or so, but it might be worth a shot.