Persistent Diacetyl in Lager

Try making a starter of some fresh yeast and add it to see if it will clean it up maybe? I've never done a lager and have no idea if it would work, just a thought though.

 

When you say 'no change', what, exactly, are you expecting to see?

 

Well, I was gonna say use a higher temp for your d-rest until I read your post... you might try krausening; add a couple of liters of fermenting starter and see what that does. A little puzzling. What was the yeast? How well did you aerate?

 

You want to do the D-rest with a few degrees plato to go, as stated. Try pitching some yeast at high krauesen, which should clean it up.

 

Did you make a starter? If yes, did you make the proper number of cells according to a yeast caluculator?

 

Are you saying that you taste it to see if it has diacetyl? I generally just raise the temp for a couple of days and assume it's gone. I have no indicators as to whether or not it was effective. Seems to work. FWIW, I'm one of the 'lucky' ones who can't taste diacetyl.

 

I am sorry you are having trouble. You have got some goog advise about pitching more yeast. When I brew a lager I do my rest when my air lock has 1 bubble every 15 seconds. I bring my fermenter up to 66 degrees for 2 days. To my taste I have not had diacetyl problems. Good luck.

 

Peter,

I am sorry to hear about your diacetyl problems. I saw that Jeff (hopfenunmaltz) recommended pitching some yeast at high krausen, hopefully this will help.

I will tell you a little ‘secret’, I have brewed many, many lager beers and I have used 2035 a couple of times to make CAP beers. I have never checked my lager beers for diacetyl and I have never conducted a diacetyl rest. I simply ferment at lager fermentation temperatures (e.g., 50°F) for 2-3 weeks and then lager for 6-7 weeks at around 40°F. I have no idea whether there was diacetyl present after the primary was complete. I can tell you that the final product had no diacetyl (and my taste buds are sensitive to diacetyl). So, maybe diacetyl is ‘processed’ during the lagering process? Maybe your diacetyl will be ‘processed’ during lagering?

Based upon my personal experience making lager beers I would highly encourage you not to dump your beer.

Cheers!

Jack

 

Peter,

I was doing some web surfing about diacetyl ‘processing’ during the lagering phase. I thought this might be useful?

“Some European Commercial Breweries actually don't do Diacetyl rests on their lagers - learned this fact from Chris White of White Labs during his talk at ANHC. The breweries that don't do them simply have a very long lagering period instead.”

http://www.aussiehomebrewer.com/forum/index.php?showtopic=54041

Cheers!

Jack

 

That sounds like a proper starter. Did you enter the production dates on the vials into the calculator? Being as lager yeast isn't used as often as ale yeast it can end up sitting around some shops for much longer than it should.

 

The traditional lager schedule did not do a rest, and had a slow reduction in temp to start the lagering phase. The secondary fermentation is when the yeast run out of sugars and switch to other compounds like diacetyl for energy (you will see this defined if you read enough about lagers and lagering). The maturation period is long due to the low metabolic rate of the yeast at low temps. A D-rest will speed the process up and save time, and it also helps blow off some of the sulfur compounds. Some even crash the temp to drop the yeast out faster and get a shorter lagering time.

Do you need to do a D-rest? It depends on the yeast strain, the amount pitched, the pitch temp, O2 introduced and more factors I am sure. The way to know is taste your beer when it is about 75% through the primary on the way to the FG. The 75% is you are 75% of the way to the FG, not the days of fermentation. If you taste Diacetyl, you need a rest, if no Diacytel you don't need a rest.

There is a discussion on lager fermentation profiles and lagering times and temps on braukaiser.com.

 

Zactly, In my experience you need to have at least one degree plato left have successful d-rest. I've struggled with diacytel issues over the years as well and found this to be most effective way to eliminate it. I have brewed lagers without any diacytel issue and no d-rest, but as a catch all I do a d-rest for all my lagers now. I just make sure there is at least 1 deg plato left to go.

Also, Pweiss, do others detect the diacytel as well? Or is it just you? I've become very sensitive to that flavor and can pick it up in many beers. I'll sit side by side with other tasters who don't pick it up at low levels. Perhaps you're just more sensitive to it than others.

I've tried adding karausen to help fix it after the fact but never had great success with that method. From what I understand that is a common method and people are successful with it. So it might work for you.