Help with Diacetyl

I brewed a Dortmunder style lager with Wyeast 2487. I made a 4 quart starter, and pitched the 1.047 beer at 50F. When fermentation slowed at 6 days I ramped it up to a 62F diacyetyl rest and held that for 2 days.
When I racked it to a secondary at 2 weeks, it was at 1.015, smelled and tasted very strongly of sulphur. I just kegged it tonight, and the sulphur is gone, but it tastes of diacetyl, which SWMBO confirmed.
I've brewed about 20 lagers so far, and this is my first that had noticeable diacetyl at kegging time.
Is there anything I can do about it now?

Man, after it is off the yeast I really don't think there is too much you can do. I do have to ask, why on earth did you do a diacetly rest after only 6 days? I usually let my lagers sit in the primary for a month, then i taste a sample, if I find any hint of diacetly, I then do a D-Rest for 48-72hrs then rack to a secondary and lager for at least another month. Sounds to me that you racked way too early and didnt give the yeast a chance to clean up their byproducts.

Newbeerguy said:

I do have to ask, why on earth did you do a diacetly rest after only 6 days?

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I've brewed about 20 lagers without the slightest hint of diacetyl using the procedure from Palmer - http://www.howtobrew.com/section1/chapter10-4.html

" [The diacetyl] rest at the end of primary fermentation consists of raising the temperature of the beer to 55-60 °F for 24 - 48 hours before cooling it down for the lagering period. "
After 6 days, it was within a couple of points of my expected terminal gravity. I let it sit on the cake for another 8 days after that.

Newbeerguy said:

Man, after it is off the yeast I really don't think there is too much you can do. I do have to ask, why on earth did you do a diacetly rest after only 6 days?

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All available evidence suggests that enzymatic reduction of diacetyl is well under way by the 6th day of a lager fermentation.

If it's because the yeast didn't take it up, then pitch some more active yeast to see if that helps. It's possible that it could be from a pedio infection, which means pitching more yeast won't help much. Is it just diacetyl that tastes off?

Brewsmith said:

If it's because the yeast didn't take it up, then pitch some more active yeast to see if that helps. It's possible that it could be from a pedio infection, which means pitching more yeast won't help much. Is it just diacetyl that tastes off?

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It is just the diacetyl.
Pitching more active yeast sounds like an interesting idea. By "active yeast", do you mean like a starter at high krausen? Or a rehydrated dry yeast?

You need activly fermenting wort, so a starter at high krausen will do the trick providing the diacetyl isn't from an infection.

gxm said:

I've brewed about 20 lagers without the slightest hint of diacetyl using the procedure from Palmer - http://www.howtobrew.com/section1/chapter10-4.html

" [The diacetyl] rest at the end of primary fermentation consists of raising the temperature of the beer to 55-60 °F for 24 - 48 hours before cooling it down for the lagering period. "
After 6 days, it was within a couple of points of my expected terminal gravity. I let it sit on the cake for another 8 days after that.

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I didn't mean to question your process. I never had a lager finish up that quick. Actually I found that if I leave my lagers in the primary for 1 month, I don't need to do a diacetyl rest at all.

You can try krausening, which has worked for me. Add a qt. of actively fermenting wort and let it reduce the diacetyl. This assumes the diacetyl is not due to an infection.

Newbeerguy said:

I didn't mean to question your process. I never had a lager finish up that quick. Actually I found that if I leave my lagers in the primary for 1 month, I don't need to do a diacetyl rest at all.

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My understanding of the diacetyl rest was that you wanted to do it while the yeast are still in suspension & actively fermenting. I've read some sources say you should do it when the beer is 2/3rds of the way to FG.
Personally, I'm not sure I need to do the rest with most lagers, though I've done it more as a precautionary measure. With many of the lagers I've made, at the time I want to do the rest, the sulphur is so strong I'm not sure I'd notice the diacetyl.

Anyway, I'm brewing a another beer with 2487 week after next, so I'll draw off 2 quarts of that while it's actively fermenting and add it to the Dortmunder. Thanks for the suggestions.

gxm said:

My understanding of the diacetyl rest was that you wanted to do it while the yeast are still in suspension & actively fermenting. I've read some sources say you should do it when the beer is 2/3rds of the way to FG.
Personally, I'm not sure I need to do the rest with most lagers, though I've done it more as a precautionary measure. With many of the lagers I've made, at the time I want to do the rest, the sulphur is so strong I'm not sure I'd notice the diacetyl.

Anyway, I'm brewing a another beer with 2487 week after next, so I'll draw off 2 quarts of that while it's actively fermenting and add it to the Dortmunder. Thanks for the suggestions.

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Correct, that is the same information I heard. I have just never been 2/3rds of the way there after 6 or 7 days...it has always taken me at least 2 weeks. I found out that what works for me, intstead of having to open up the carboy and checking to see if it's almost done is to just let it sit in the primary for a month. I never had any problem since. But let us know is krausening does the trick, I am interested.

I sampled the Dort last night, and SWMBO & I agreed it was still buttery & would prefer not to drink it as is.
So I took 2 quarts from a batch I was brewing last night, and split part of my 2487 starter into that 2 quarts. It had a nice krausen this evening, so I pitched it into the Dort, which now has a small layer of foam on top.

I had diacetyl once. I just pitched 1/2 packet of dry yeast and let it sit for another week in the keg at room temp.

Replaced the valve with an airlock.

I let the Dort ferment for 4 days, then a D-rest for another for days.
I kegged it tonight, and the sample tastes much better, no diacetyl noticeable.
Thanks for the help!

Thanks again for all the feedback. Now that the Dortmunder is on tap, I took 2L to my drinking buddies, and none of them could find a hint of diacetyl, even after I asked them to look for a hint of it.

Alas, now I have a Dunkel lager (brewed with 2308) with a diacetyl issue. I've brewed most of my lagers with Wyeast 2124 & 2206, and haven't had any issues with them.
I pitched a Doppelbock to the Dunkel yeast cake, and that is a clean & tasty beer (note to Bob - please don't respond chastising me about this "bad practice").

I'm starting to suspect that my 4L starters aren't sufficient with certain yeasts, or that I'm not starting the diacetyl rest early enough. By the time I get a lager in D-rest, it's already 80-90% fermented.

If anyone else has had similar experiences, I'd like to hear about them.

How long are you letting the ferment go?

If you are only going 4 days primary for a lager, and then only 4 more days at a D rest, then you are not leaving it long enough. It is not an ale, and primary fermentation can easily take more than a week at lager fermentation temps. I'd give it two full weeks before doing anything, including a D rest.

I had a diacetyl issue in a pilsner. I now calculate what SG represents 70-75% primary fermentation complete and do a diacetyl rest then. I ferment most of my lagers at 50F and raise to 60F for the rest. After 48 hours, I rack and lager for 3-8 weeks depending on the beer. Haven't had a problem since then. Oh, and one thing I've been doing that's helped is to make sure to pitch your starter when the temperature of the wort is 50F AND the temperature of the starter is also 50F. So I cool them in the temp controlled freezer until they are both 50F and then pitch.

Brewsmith said:

How long are you letting the ferment go?

If you are only going 4 days primary for a lager, and then only 4 more days at a D rest, then you are not leaving it long enough. It is not an ale, and primary fermentation can easily take more than a week at lager fermentation temps. I'd give it two full weeks before doing anything, including a D rest.

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Thanks, I know it's not an ale
The 4 days/4 days was after pitching a 2L starter at high krausen to the month old beer.