Strong diacetyl in finished Oktoberfest . . . any fixes?

[OneEyedWillie]

Well, it was inevitable. After three years of homebrewing, I have finally made a batch that I just turns my stomach when I taste/smell it. If you were to take a spoonful of Country Crock butter, microwave it to a nice liquid consistency, and drink it, then you would an accurate sample have my 2011 Oktoberfest.

I pretty much know where the Diacetyl took control. After brewing, I hook up my wort chiller to the kitchen sink - usually in about 15-20 minutes the temp is around 75F and is ready for pitching. However, Texas had record breaking heat this year, and cooling wort down was a true challenge this summer. In the case of the Oktoberfest, the yeast (White Labs Oktoberfest/Marzen Lager) was pitched closer to 86F. I know, I know....way too high. But it took well over 30 minutes just to get it to that point, and I was running late to another event, so I had to do what I had to do.

But, because I knew I did that, I allowed for an extended primary fermentation (14 days at 55F) and a 6 day diacetyl rest before heading to the lagering room for 6 weeks at 45F (where is still remains).

I checked it this weekend, and it's liquid butter.

Despite all homework and research that has been performed, I'm not completely sold that this brew is done for, but I'm not exactly too sure what to do next - aside for time. I have considered adding a little more DME and re-pitching a Nottingham dry yeast packet to see if a second round would clear up any leftover diacetyl, but I don't know if that's a good idea or not.

So, now, after maxing out all my brewing knowledge and additional hours of online research, I turn you to all - the main source of insight and wisdom of all things beer.

Is there anything I can do now that my Oktoberfest is completed to help reduce the overbearing diacetyl flavors?

 

[organ]

I've pitched in the 80s with no diacetyl problems. What temp did you maintain for the diacetyl rest? Your yeasts may have needed more than 6 days to clean up after themselves.

 

[OneEyedWillie]

The diacetyl rest was at a consistent 74F.

 

[KingBrianI]

I think your idea of adding some yeast and dme is good. You just may want to get it active before adding it. I'd get the notty actively fermenting a 1 L "starter" and at peak activity add it to your room temp lager. The active yeast will hopefully finish chewing on the dme and turn to the diacetyl.

 

[Brewpastor]

Why make lager when it is so hot? You are going to create diacetyl precursors unless you chill down a lot more then you were able to and the yeast is not going to produce the flavors you expect unless it ferments cooler. I would not have expected diacetyl at the fermentation temps you quote, esters yes, but not diacetyl. That doesn't mean you will make bad beer, but it won't have the classic Oktoberfest character you expect.

As for the butter, give the suggestions a try. But I wouldn't hold my breath waiting. Best of luck!

 

[Brewpastor]

The issue is probably a bacterial infection. From Palmers "How to Brew":

Diacetyl
Diacetyl is most often described as a butter or butterscotch flavor. Smell an unpopped bag of butter flavor microwave popcorn for a good example. It is desired to a degree in many ales, but in some styles (mainly lagers) and circumstances it is unwanted and may even take on rancid overtones. Diacetyl can be the result of the normal fermentation process or the result of a bacterial infection. Diacetyl is produced early in the fermentation cycle by the yeast and is gradually reassimilated towards the end of the fermentation. A brew that experiences a long lag time due to weak yeast or insufficient aeration will produce a lot of diacetyl before the main fermentation begins. In this case there is often more diacetyl than the yeast can consume at the end of fermentation and it can dominate the flavor of the beer.

 

[osagedr]

Sounds like your d-rest took place after FG had already been attained. You want to do it about six or eight gravity points above FG.

See if the following thread helps you at all:

https://www.homebrewtalk.com/f14/will-work-205761/

 

[mattldm]

Im having a similar problem with my Oktoberfest lager this year.
It tasted good when kegging, no diacetyl present at all. Now three weeks later I pulled a sample and its all buttery and blah. Im really bummed as this was my first lager brew and it seemed everything was going great. I hope its salvageable as I planned on having an event and dont have time to rebrew another lager.

Mine is kegged and carbed so would it kill it to rack it back to a carboy and add some additional yeast to try and clean it up or should I just let it sit for a few more weeks and see if it goes away?
any help would be appreciated!

 

[Yooper]

Im having a similar problem with my Oktoberfest lager this year.
It tasted good when kegging, no diacetyl present at all. Now three weeks later I pulled a sample and its all buttery and blah. Im really bummed as this was my first lager brew and it seemed everything was going great. I hope its salvageable as I planned on having an event and dont have time to rebrew another lager.

Mine is kegged and carbed so would it kill it to rack it back to a carboy and add some additional yeast to try and clean it up or should I just let it sit for a few more weeks and see if it goes away?
any help would be appreciated!

It won't go away, and will probably get worse with time.

I'm not sure that even repitching at this point would do anything but it might be worth a shot if you can't stand to drink it as is.

When you kegged it, and detected no diacetyl present at all, I have to believe there was some. What happens in small amounts, is that diacetyl presents as a "slick" or slightly oily mouthfeel or a bit of slickness on the tongue. It's not buttery or butterscotch until there is lots more. But it gets worse during lagering, not better, so sometimes a lager with just a wee hint of a slickness turns into a butter bomb.

 

[mattldm]

It won't go away, and will probably get worse with time.

I'm not sure that even repitching at this point would do anything but it might be worth a shot if you can't stand to drink it as is.

When you kegged it, and detected no diacetyl present at all, I have to believe there was some. What happens in small amounts, is that diacetyl presents as a "slick" or slightly oily mouthfeel or a bit of slickness on the tongue. It's not buttery or butterscotch until there is lots more. But it gets worse during lagering, not better, so sometimes a lager with just a wee hint of a slickness turns into a butter bomb.

I think you are right, There probably was some diacetyl that I didnt detect at kegging but its really apparent now. I guess Ill try repitching some yeast and see if it helps!

 

[OneEyedWillie]

. . . rack it back to a carboy and add some additional yeast to try and clean it up . . . .
any help would be appreciated!

This is exactly what I did last year when I had this problem. I released all of the pressure from the keg, racked back into a carboy and added some Extra Light DME as well as pitched in just a small bit of Nottingham. I allowed it to set for two weeks at 72F, and by that time, the cheap movie theater butter aromas and flavors had dissipated.

I kegged it as usual, and served it at a homebrew club party at my house. Though the members knew I was having this problem with the brew, they all admitted that they could not detect any diacetyl flavors and that it was a good brew.

 

[hopalotamus]

Had a buttery helles that I had forgot to do a drest and had kegged took it out of the fridge and set it in a warm room for a few weeks and it was much better when rechilled almost no butter taste