My pale ale has diacetyl! Help me save the batch

OK so I have this 6 gallon batch of my pale ale sitting in primary, which is a recipe whose results I've been very happy with in the past.

What I did differently on this batch was I tried out the olive oil thing instead of aerating the wort, and although the fermentation looked normal to me, maybe I didn't get enough in there, or maybe too much (?) but now I've got a distinct diacetyl flavor in this beer that I'm trying to get rid of. I'm assuming the batch was just under aerated (for lack of a better word) and that's why it turned out like is has, but I'm open to other opinions. FWIW my OG was 1.048 and it's now down to about 1.009 or so, so I'm happy with the attenuation.

I brewed this batch on September 26th, so it's been in the primary for about 2.5 weeks now. I added dry hops on October 4th (one week after primary), and pulled them out three days ago. At that time, I checked the gravity and noticed the diacetyl aroma and flavor. So, instead of immediately cold crashing as I had planned, what I did was twist the fermenter back and forth a bit in an attempt to rouse the yeast.

I just opened it up to check on progress. Hop aroma is still there, but so is the diacetyl along with the flavor. Maybe not quite as strong, but definitely still there. So, I've roused the yeast again, this time by taking a sanitized plastic spoon and physically stirring up the sediment from the bottom.

If this doesn't help out, what else can I do to get rid of the diacetyl? I was considering making a starter using the same yeast (S-04) and just dumping it in there after a couple of days. Any chance that could help clean things up?

What was the fermentation temperature, and what is the temperature now?

Primary fermentation was at 65-68F. It was pretty much finished after a week when I added the dry hops (gravity was 1.010), so I pulled it out to make room for another fermenter and let it come up to room temps, which were more like 72-75F. It is still at room temp now, so around 74F.

Also, this is exactly the same procedure I used on previous iterations of this recipe that did not exhibit the diacetyl.

Yeah, those temps shouldn't cause a diacetyl problem.

Dumb question, but are you sure it's diacetyl?

Well, it tastes and smells buttery, like other beers I've had with diacetyl problems (at competitions, and the occasional commercial beer) I suppose it could be something else, but if it is I wouldn't know how else to classify it.

Well, I wouldn't stir it anymore. At 1.009, the beer is finished and you don't want to oxidize it.

I think I'd leave it at 70-72 degrees for another week and see if it improves. It might.

If not, I'm not sure what will work. I will have to give it some thought.

What Yooper said...

Leave it at room temperature but add at least 1 tsp of dry yeast and let sit 7-10 days and I'll bet it will be gone and become very tasty again. Always works for me....OK, 2 out of 2 times...

Do I need to hydrate the yeast or anything, or do you just dump it in?

Just dump it in and reseal. Don't forget to purge any air out also.

Any additional offgassing will just serve to pressurize and carbonate.

Check back in a week by tapping a brew off...

time, time, time...

I've always understood that certain yeast strains were more likely to cause diacetyl than ferm temps... that, and taking it off the yeast cake before they can clean it up (which it sounds like isn't the problem). What yeast was it? Other than that - just wait.

I went ahead and sprinkled some more S-04 from a fresh packet in there tonight. I guess I'll give it another week and see how it tastes. If it clears up, I'm actually thinking about dry hopping it again...

If it's at 1.009, then the beer is done...the more you mess with it, the more you stand to mess it up worse. The diacetyl sometimes goes away after it ages.

I'd rack it to the secondary and let it sit for a couple weeks, keg and then have at it. It will probably change for the better during that time period.

In my experience, unless a fermentation is stuck real early, say above 1.020, then I worry about it (unless it's a big beer,) otherwise opening up the fermenter and adding things and adding O2 at the same time, usually ends up with bad results.

Hope it ages well.

cheers

~r~

With my last batch it was fine when I put it in the keg.

All I can tell you is what worked for me.

I had it under gas in the keezer for a week while I was on a business trip. When I came back it was buttery so I removed it from the keezer, released all the gas then added the dry yeast, resealed, purged air then let it sit for a week at room temp and it was good again. That's all I did.

Not exactly sure of the FG, but I know it was under 1.010. It's not about producing any more alcohol as much as it cleaning up after itself.

If it's at 1.009, then the beer is done...the more you mess with it, the more you stand to mess it up worse. The diacetyl sometimes goes away after it ages.

Click to expand...

I'm going to dump it if I cannot get rid of the diacetyl. I'm not going to bottle up a couple cases and hope for the best in a month or two, because I would spend less time screwing around just to brew it again, and those bottles occupy valuable real estate in my house.

Well, I've tasted it again this evening and it is much cleaner now. I don't get any diacetyl flavor anymore, so I decided to go ahead and bottle it. I'm going to keep that trick in my back pocket for future reference in case this ever comes up again.

Hell, its only like 3 weeks old. I dont even mess with my pale ale for 6 weeks. You still have at least 2 weeks or so to let the flavors all come together and smooth out. Also, corbonation will change everything. RDWHAHB!