Diacetyl in pilsner

[RealRayDizzle]

I have been brewing all grain for over a year now, write my own recipes in beersmith and have brewed a few lagers. I have made 4 attempts at a pilsner and all have had issues. My other lagers have been fine.
This time the pilsner has a significant diacetyl flavor after about 2 weeks at 36 deg.
I used german lager wlp830
2 weeks @ 54deg
3 days diacetyl rest at 72 ish(texas winter for ya)
2 weeks so far at 36

Tasted fine when transfering to keg, but now very noticable diacetyl flavor

Will this age out, or should I try bringing keg back up to room temp for a couple days?
It's almost fully carbonated already as well.

 

[imasickboy]

Two weeks might be too long @54. You generally want to raise to diacetyl rest temp with 2-5 gravity points before expected final gravity. This is obviously a guessing game, but with repeated practice, you can do it.

 

[RealRayDizzle]

Maybe the yeast strain is less forgiving? my american pre prohibition lagers, and schwarzbier black lager never had this problem with the same time table.

Once I get this one fixed I can try changing times and temps to keep it from happening again on next batch.
Would hate to dump it, may not be ruined yet.

 

[dmtaylor]

I'm coming to realize there's a problem with the standard homebrew guidance of 3 days for a diacetyl rest. I think this really needs to be 3 WEEKS.

Warm it up Kriss.

 

[Ralphie0523]

Fine when transferred to keg but not fine after 2 weeks in keg? Seems like you have an infection somewhere in the kegging setup. I would clean everything super well to try and rule it out. Change gaskets too for good measure.

Of course, it does beg the question of being sure it is diacetyl and not some other off flavor, but only a chemical analysis can really say for sure.

 

[Qhrumphf]

Ramp up for rest, give it a few days, then start doing force tests- take a small sample, cover it and heat it to 150F, hold it for 15 mins, then cool it back down. Once it's chilled, smell and taste it.

This will quickly convert any acetolactate (diacetyl precursor) into diacetyl. Acetolactate is either imperceptible or has a much lower threshold than diacetyl, but will form diacetyl.

Repeat daily (or every few days) until you no longer perceive diacetyl after the force test.

 

[couchsending]

Never done a diacetyl rest, never had diacetyl in a lager.

Pitch more yeast. A lot more. Pitch it cold and let it warm slightly.

And lots of O2

Ferment should be done in 5-7 days even at 48*. Slowly step down to 39 and leave for a week or two then slowly to 30 and leave for 2-3 more. Lager yeast can consume diacetyl all the way down to the low 30s.

 

[Conehead]

I have never had diacetyl since using the fast ferment process. I try to let it go as long as I can, usually 67 days and ramp up quickly. This is when I get a strong sulphur smell for a day or so.

 

[Vale71]

54°F is pretty warm for a lager. Did you by any chance pitch even warmer and then cool to 54°F once fermentation signs became visible?

 

[Brooothru]

Fine when transferred to keg but not fine after 2 weeks in keg? Seems like you have an infection somewhere in the kegging setup. I would clean everything super well to try and rule it out. Change gaskets too for good measure.

Of course, it does beg the question of being sure it is diacetyl and not some other off flavor, but only a chemical analysis can really say for sure.

+1. Had the exact same problem a couple of years ago. A BJCP judge recommended steam cleaning all my equipment and scrubbing down my entire brew area. I did scrub down the cement block walls and concrete floor, but then told SWMBO that all the plastic had to be replaced with stainless. Shhhhh. Don't rat me out.

I'd definitely suspect an infection. WLP-830 is a solid yeast and doesn't produce a ton of diacetyl. But also +1 on the suggestion to increase the time for diaceytl rest. Three to 5 days AT 68~72F will help the remaining yeasties complete their cleanup chores. No need to rush it.

Brooo Brother

 

[mongoose33]

Never done a diacetyl rest, never had diacetyl in a lager.

Pitch more yeast. A lot more. Pitch it cold and let it warm slightly.

And lots of O2

Ferment should be done in 5-7 days even at 48*. Slowly step down to 39 and leave for a week or two then slowly to 30 and leave for 2-3 more. Lager yeast can consume diacetyl all the way down to the low 30s.

The yeast can do that, but it's a much slower process.

As far as never having had diacetyl in a lager....well, perhaps. It's possible you're not sensitive to it and have never noticed it, but others would. And it's possible you're using yeast strains that produce reduced levels of the precursor, or are otherwise allowing for it to be consumed by the yeast.

What people can perceive, what they like varies from palate to palate. I don't care for Mosaic hops, for instance. I can almost always taste it in a beer, and that disqualifies it from my drinking more of it. Others, of course, like it.

I have a friend with a palate that is unbelievably sensitive. I have him try all my beers (new ones, anyway) looking for off-flavors. I can't always trust my own ability to detect them.

 

[bierhaus15]

With a healthy fermentation, you should need no more than 8-10 days combined fermentation and D-rest for average strength lagers. Any longer and I'd start to look at yeast health and pitching. Once the yeast is finished fermenting and VDK has dropped, there is no reason to leave the beer on the yeast. By then, the beer should be off yeast and starting the lagering process. A very slow drop in temperature is fine, although the the bulk of yeast should be removed prior, in part to limit proteolytic enzymes and other issues like yeast degredation, ect.

 

[Qhrumphf]

Depends on the strain. One I've used would take 3-4 weeks to finish, no matter what you did. I don't use that strain any more.

The Weihenstephan 34/70 yeasts (34/70, WLP830, WY2124, etc), 8-10 days ferment and clearing diacetyl (if free-rose to the upper 60s when maybe 70% done) is my experience.

But as I said above, I always go by a forced test, not the beer straight, and definitely not an arbitrary length of time. First pitch takes a little longer to clear diacetyl. 2nd and 3rd gens are pretty quick. 4th gen it slows down, 5th gen takes forever so I usually won't go past 4 (or often 3 gens).

 

[couchsending]

The yeast can do that, but it's a much slower process.

As far as never having had diacetyl in a lager....well, perhaps. It's possible you're not sensitive to it and have never noticed it, but others would. And it's possible you're using yeast strains that produce reduced levels of the precursor, or are otherwise allowing for it to be consumed by the yeast.

What people can perceive, what they like varies from palate to palate. I don't care for Mosaic hops, for instance. I can almost always taste it in a beer, and that disqualifies it from my drinking more of it. Others, of course, like it.

I have a friend with a palate that is unbelievably sensitive. I have him try all my beers (new ones, anyway) looking for off-flavors. I can't always trust my own ability to detect them.

Perhaps... I have a pretty good understanding of what Diacetyl smells and tastes like as well as what the texture of it is like. I’ve never been through sensory training where you’re provided samples at certain levels to determine what your sensitivity to it is but I bought one of the sensory kits from Siebel and I wasn’t blind to at least anything in the kit I bought at the thresholds supplied by the kit.

Based on the yeast calcs I aim to pitch around 2m/ml/*plato and always pitch low and let it warm to 48 or 52 depending on the strain but generally never go past that. Only lager yeast I’ve had take forever is the Hessian Pils from The Yeast Bay, regardless of pitch rate it seems. Primarily use the Andechs strain or a blend of Saaz strains. I loath the Augustiner yeast and have only started using the liquid form of 34/70 again recently. Never get above 52 and never experience diacetyl in my lagers. I do forced VDK before lowering below 39.

Definitely made some diacetyl bombs in my day but most of those were caused by hop creep.

 

[Qhrumphf]

but most of those were caused by hop creep.

That's my primary offender as well (the only way I perceive it under normal "butter" forms, in my case butterscotch). Though in doing forced tests, I've learned how to perceive it normally, where it's more a watery alcohol type character.

If you can perceive it at the Siebel kit recommended dilution, you're definitely not blind to it.

 

[SEndorf]

Depends on the strain. One I've used would take 3-4 weeks to finish, no matter what you did. I don't use that strain any more.

The Weihenstephan 34/70 yeasts (34/70, WLP830, WY2124, etc), 8-10 days ferment and clearing diacetyl (if free-rose to the upper 60s when maybe 70% done) is my experience.

But as I said above, I always go by a forced test, not the beer straight, and definitely not an arbitrary length of time. First pitch takes a little longer to clear diacetyl. 2nd and 3rd gens are pretty quick. 4th gen it slows down, 5th gen takes forever so I usually won't go past 4 (or often 3 gens).

Interesting,
My experience as well.
Primarily depending on the strain, but I've found the length of time looks like an inverted bell curve.

 

[RealRayDizzle]

I went ahead and pulled the keg to warm, as I was writing notes in beersmith I noticed that I was mistaken in my initial post. I used WLP800 in this version of the recipe not WLP830.

WLP800 more difficult to clear up than the WLP830?

at this point I may just quit on WLP800 as when I make german Hells i had been using WLP830 and never had this flavor

 

[Vale71]

Czech yeasts are known for being stronger diacetyl producers as a diacetyl note has always been typical of the traditional Czech styles.
WLP800 is certainly not as extreme as WLP802 but it's still definitely a contributing factor.

 

[dmtaylor]

WLP800 is a known producer of diacetyl. In fact it is an “ale” cerevisiae strain so it might not love cool temperatures as other pastorianus strains might.

 

[RealRayDizzle]

Thanks all,

After a couple days it tastes like its clearing up a bit.
This exercise also may have pinpointed the problems I have been having with most of my pilsner attempts.

I may just switch to WLP830 for future pilsners, which others are popular for this style? WLP830, WY2124 ?

 

[dmtaylor]

Thanks all,

After a couple days it tastes like its clearing up a bit.
This exercise also may have pinpointed the problems I have been having with most of my pilsner attempts.

I may just switch to WLP830 for future pilsners, which others are popular for this style? WLP830, WY2124 ?

Great to hear.

I love 2206 and WLP833. Also S-189 is a very good dried yeast option, better than W-34/70 in my opinion. And let's not forget WLP940 Mexican, that's a really good one too.

 

[Qhrumphf]

Other strains may impart nuances you may prefer, but 830/2124/34-70 is very clean, forgiving of temp, a workhorse and very very fast. It's (likely) the #1 lager yeast in the world (I recall that being the case but I may be wrong) for a reason.

 

[Robert65]

Other strains may impart nuances you may prefer, but 830/2124/34-70 is very clean, forgiving of temp, a workhorse and very very fast. It's (likely) the #1 lager yeast in the world (I recall that being the case but I may be wrong) for a reason.

The greatest potential downside I can think of is that, to be so fast and clean, these Weihenstephan 34/70 derived yeasts are necessarily powdery, and so can be slow to clear. Not a problem for brewers who filter, centrifuge or lager a long time, but something to keep in mind as a homebrewer. 2206 drops like a rock, but is a little less attenuative and a little slower going.

 

[Qhrumphf]

The greatest potential downside I can think of is that, to be so fast and clean, these Weihenstephan 34/70 derived yeasts are necessarily powdery, and so can be slow to clear. Not a problem for brewers who filter, centrifuge or lager a long time, but something to keep in mind as a homebrewer. 2206 drops like a rock, but is a little less attenuative and a little slower going.

Gelatin, isinglass, or biofine all seem to make pretty short work of it in my experience.

 

[RealRayDizzle]

Unearthing this thread after a month to share an interesting find/update.

It is averaging about 65-68 deg here in Texas and after being frustrated with the taste of this pilsner I decided to chuck it in the garage until I got around to dumping it.

last week I remembered it, and decided to try a bit before dumping it. temp warm was about 70 deg in the keg, tasted fine. No more butter flavor, or any off flavors for that matter.

got excited so chilled it down. now a week later, tried it again at 38 deg... buttered popcorn is back...

I used a picnic tap to pull the sample, used it on other beers with no flavor issues so can't be the beer/gas lines(replaced gas lines before carbonating a Kolsch that tastes fine)

So, I am only getting this off flavor after the beer has been chilled...
infection maybe? it has developed a funk to it, like a slight foot/skunky taste, also only when cold.

 

[Conehead]

I have never had diacetyl since using the fast ferment process. I try to let it go as long as I can, usually 67 days and ramp up quickly. This is when I get a strong sulphur smell for a day or so.

Should read 6 - 7 days.

 

[shaky6]

Are you sure it's a diacetyl thing and not DMS from the pilsner?

 

[Vale71]

Unearthing this thread after a month to share an interesting find/update.

It is averaging about 65-68 deg here in Texas and after being frustrated with the taste of this pilsner I decided to chuck it in the garage until I got around to dumping it.

last week I remembered it, and decided to try a bit before dumping it. temp warm was about 70 deg in the keg, tasted fine. No more butter flavor, or any off flavors for that matter.

got excited so chilled it down. now a week later, tried it again at 38 deg... buttered popcorn is back...

I used a picnic tap to pull the sample, used it on other beers with no flavor issues so can't be the beer/gas lines(replaced gas lines before carbonating a Kolsch that tastes fine)

So, I am only getting this off flavor after the beer has been chilled...
infection maybe? it has developed a funk to it, like a slight foot/skunky taste, also only when cold.

This doesn't make sense either from a chemical or a biological standpoint. The only explanation I can think of is that for some sensory-related reason you only perceive this off-flavor when the beer is cold. To verify this you could pull a small sample, taste it right away to see if the off-flavor is present and then quickly warm up the beer to ambient temperature (this must be done quickly in order to not let the beer oxidize which would introduce another variable) and then try again and see if the off-flavor seems to have disappeared.

 

[VirginiaHops1]

That's my primary offender as well (the only way I perceive it under normal "butter" forms, in my case butterscotch). Though in doing forced tests, I've learned how to perceive it normally, where it's more a watery alcohol type character.

If you can perceive it at the Siebel kit recommended dilution, you're definitely not blind to it.

Curious on the bolded comment. I've started doing forced VDK tests on my last couple batches. I haven't gotten a popcorn/butter smell or taste on any of them but I do get a weird almost solvent-like alcohol smell kind of like what you describe. Are you saying that's diacetyl? I assumed that was some other off-flavor produced from heating the sample up to 160 and not diacetyl. Those beers were immediately cold crashed and packaged all turned out very good with no diacetyl in the final product(to my palate or others).

 

[Qhrumphf]

Curious on the bolded comment. I've started doing forced VDK tests on my last couple batches. I haven't gotten a popcorn/butter smell or taste on any of them but I do get a weird almost solvent-like alcohol smell kind of like what you describe. Are you saying that's diacetyl? I assumed that was some other off-flavor produced from heating the sample up to 160 and not diacetyl. Those beers were immediately cold crashed and packaged all turned out very good with no diacetyl in the final product(to my palate or others).

I wouldn't say what I perceive is solventy, and I also don't know what you're perceiving. I'm inclined to say what you're getting is probably just ethanol, not diacetyl. The way I perceive diacetyl is pretty atypical from what I can garner. And I perceive it the same way or without a forced test. I thought I was just blind to it for a long time.

What's your forced test procedure? If you're evaluating hot, your alcohol smell is definitely just alcohol.

 

[VirginiaHops1]

I wouldn't say what I perceive is solventy, and I also don't know what you're perceiving. I'm inclined to say what you're getting is probably just ethanol, not diacetyl. The way I perceive diacetyl is pretty atypical from what I can garner. And I perceive it the same way or without a forced test. I thought I was just blind to it for a long time.

What's your forced test procedure? If you're evaluating hot, your alcohol smell is definitely just alcohol.

Maybe solvent wasn't a good descriptor, I think it's just a really strong hot alcohol smell. Ethanol sounds likely but when I first did it I was wondering what the heck it was and if it was normal. I heat the sample to around 160 or so then let it sit 15-20 minutes. I cool it before I smell/taste but I think I did smell some of them hot which is when the smell I described was much worse.