Oktoberfest with a side of diacetyl

[ian-atx]

Hey there. So I have an oktoberfest beer that has been lagering for about 6-7 weeks and is exhibiting some diacetyl (or so I believe). I did a d-rest, but maybe I did it wrong or something...not sure. Anyway, this beer is not bad, but has a hint of diacetyl and I would be interested in getting rid of it if possible, that doesn't involve months of lagering.

Would bringing the beer up to mid 60's for a few days do anything after a long period of lagering? Anyone have any other ideas?

I need to serve this beer in ~2 weeks...and if I can't get rid of the diacetyl, no worries, but it would be nice. Any help would be much appreciated.

 

[BigEd]

Assuming it is diacetyl you could try bringing the beer back up to the mid 60s for a few days along with gently rousing the yeast.

 

[944play]

Hit it with some fresh wort and healthy yeast. The refermentation should chew up the diacetyl. This is one of the advantages of kraeusening.

 

[ian-atx]

Hit it with some fresh wort and healthy yeast. The refermentation should chew up the diacetyl. This is one of the advantages of kraeusening.

Hrmm. I would assume some us05 and dme would fit the bill if I don't have any fresh 'real' wort?

 

[ian-atx]

So this is the game plan:

Create starter after work, dump starter during activity of the starter into the keg of beer (it will be out of the fridge during this time) and seal it back up. Check back in a couple days. If it appears to be good, then back in the fridge and carb the bad boy up. Will this be drinkable in anyway by the 16th? Who knows.

Also, just for more information: When I did the initial diacetyl rest, it was roughly about 75% fermented. I did not taste any diacetyl, but went ahead and did it. Not sure if this diacetyl is from a failed d-rest or is from oxidation occurring from racking the beer/moving around.

 

[markg388]

i don't do d-rests for the same reason. everyone on the internet says to do it, but my tastebuds tell me it doesn't help anything. I pretty sure with lager brewing less is always more. I'm gald i'm finally not on my own island on this issue . Good luck getting rid of it

 

[cactusgarrett]

You also might be getting lucky in the yeast strain you're using. Different ones are more/less "susceptible" to residual diacetyl.

 

[ian-atx]

Just an update to this thread...

So last thursday I created a small starter (less than a liter, and after letting the keg of beer warm up a bit) and hit it with some US05. Once fermentation on that starter was starting to krausen/foam up, I pitched into the keg of beer. Closed it up, hit with a touch of co2 to seal and left it until Sunday night.

Gassed off the beer a touch and then threw it back in the fridge.

Monday after work, hooked it up to co2 and took a taste. Aside from having some sediment and lack of clarity in what was once a clearish beer, the diacetyl was significantly reduced. Could get a hint of it, but nothing like before.

I think if I had more time to wait I would let the beer clear for a couple weeks before really serving, but that is not the case. It is still drinkable and tastes decent. Next lager will be a much better improvement.

 

[WVbrewer]

I'm having the same exact issue. I used saflager 34/70...fermented 2 weeks @ 45f, did d-rest for 3 days, racked to secondary for 6 weeks @ 40f, racked to keg (tasted great) and carbed for 3 weeks, tasted last night. Butter and caramel all over this beer. This is my first Oktoberfest. Before I take action let me give you folks the recipe....perhaps my grain bill is giving me the flavor, not the diacetyl:

5 Gallon
5lb pils
5lb munich
.5lb cara munich 55l
.5 crystal 40l
.25 carapils

1.25 oz hallertau 3.8 (60)
.5 oz hallertau 3.8 (15)
Saflager34/70

24 ibu
11 srm
1.061 og-1.014fg
5.4%

Any Thoughts? Thanks.

 

[winvarin]

subscribing to this thread. Doing my first lager in ages and my first lager ever with dried yeast. Interested in feedback

 

[WVbrewer]

Quick follow up, and a lesson learned:

Made a 500ml "starter" with nottingham. Removed carbed keg from the fridge and brought to room temp.....Started to add starter (this is where it got interesting) and quickly fumbled for the corny lid cause that baby foamed up in a hurry. I somehow got the lid on and sealed before the floor was covered in beer.

Hope it works. Last lager I used S-23 @ 45f with no diacetly at all.

 

[winvarin]

Quick follow up, and a lesson learned:

Made a 500ml "starter" with nottingham. Removed carbed keg from the fridge and brought to room temp.....Started to add starter (this is where it got interesting) and quickly fumbled for the corny lid cause that baby foamed up in a hurry. I somehow got the lid on and sealed before the floor was covered in beer.

Hope it works. Last lager I used S-23 @ 45f with no diacetly at all.

Not to hijack the OP's thread, but how long did your s-23 ferment take? I did a 1.054 pils a week ago. Pitched at 70F, cooled to 65F over a few hours, then dropped to 52F after fermentation got going. I was at 52F by about 18 hours after pitching.

Today is day 6. As of this morning, the krausen is noticeably reduced and I am getting bubbles through the airlock. I was going to wait until day 9 or 10 before checking the gravity and deciding whether it is time to bump up my temp for a diacetyl rest.

Just wondering how much (percentage wise) I should expect my gravity to drop before warming up.

 

[WVbrewer]

Winvarin, 9-10 days sounds right. I did a d-rest when I hit 80% of my anticipated final gravity. Worked well for that yeast.

 

[winvarin]

Glad you brought up the 80% thing. How exactly do you calculate that? For this batch, I started at 1.054 and anticipate a final gravity of 1.015 according to the recipe calculator at hopville.com. My thought is that I would calculate 80% like this. 1.054-1.015 = 39 points. 80% of 39 points is roughly 31. So I would want to perform a diacetyl rest at approx. 1.023. Does that sound correct?

Then just ramp up 10 degrees and ferment to my expected finishing gravity?

 

[funkswing]

Here is my experience with diacetyl and lagers:

First off, I have concluded that if you don't taste diacetyl after primary, then you don't need a D-rest (which is after all a half-assed safety net of a process). In fact, I don't think you ever really need a D-rest if you pitch an adequate amount of yeast, and you pitch at fermentation temps. Pitch a lager yeast warm and you better plan on doing a D-rest.

Secondly, diacetyl that forms in the serving container, whether if be a keg or bottles, is from one thing only......poor sanitation. I know it may be hard to believe, but this is seriously what causes 99% of the diacetyl off-flavor when you didn't taste it after fermentation.

Now poor sanitation might not be your method/sanitizer's fault. If you are bottling, it could be your old bottling bucket, or the spigot in it. No sanitizer will work on an old, scratched plastic piece of equipment.

With a keg, who knows? Did you run sanitizer thru the poppets and dip tube? You just have to be thorough.

Your siphon? Is it old, cracked or fractured? You need to get a new siphoning hose/auto siphon about once a year or two.

How to fix it?? I wouldn't add yeast; esp. not a non-flocculating US-05 to a lager that is supposed to be clear and served in two weeks.

Let the yeast sediment do the work for you. In bottles: lie them horizontally for a week, then put them back upright. This lets the yeast stay in contact with the beer longer, cleaning it up. In a keg: hell you could just turn your keg upside down for a couple of days, then back upright. Taste beer a couple of days later, then repeat if necessary.

 

[WVbrewer]

Winvarin, yeah...you got it.

Funkswing, Indeed, pitching warm will encourage diacetyl. However, I've never had a problem with it when using s-23. Perhaps there is a sanitation issue I'm encountering, but I've always associated contamination with sour flavors, not butter flavors. Perhaps I've been lucky!

 

[funkswing]

Yeah, with a lager or some highly attenuative ale yeasts it can be a sign of contamination.

Caused by Contamination
There is another way to get the buttery, diacetyl flavor in beer. This is the diacetyl contribution that brewers would rather not talk about: contamination.

That's from this BYO page.

 

[curlyfat]

Yeah, with a lager or some highly attenuative ale yeasts it can be a sign of contamination.

That's from this BYO page.

So, it would only appear in lagers, not ales? What sort of "contamination" causes that?

I ask because I make ales very successfully, and have for years. Everytime I make a lager, though, I get diacetyl that doesn't seem to appear until the keg. Is my issue really sanitation? I've never had a "contaminated" ale, and chalked my lager failures up to inadequate pitching. I want to attempt a lager again soon and don't want to waste 2 months of fermenter space on another failure.

EDIT: I did more reading that article, and I think this is pertinent, in respect to diacetyl that shows up late in the proccess, referencing cold crashing or lagering to soon:

Even though the diacetyl can’t be tasted, however, the beer might contain high levels of the precursor, acetolactate, which can be converted to diacetyl. Once the yeast is removed, there is no way to get rid of the diacetyl.

In addition, the article mentions that the bacteria that cause diacetyl in a contamination scenario are lactobacillus and pediococcus. Both of these cause some other pretty funky tastes, and I would think if they're a problem in a brewery, they would be noticed in many different styles.

So, sorry for the thread hijack, and I may have answered my own question. I'm going to try another lager with tons of yeast pitched, and some more patience during primary fermentation.

 

[funkswing]

What lager yeast are you using? Some def. are more prone to producing diacetyl then others.

My favorite lager yeast is the Urquell 2001. Basically no diacetyl production and fairly attenuative.

It can also be caused by oxidation after fermentation. As in poor siphoning.

Do you pitch at fermentation temps or at >60 F?
How big of a yeast starter do you make? Is it multi-step? Are you using a propagator/activator, vial, or dry yeast?

 

[curlyfat]

My last "failure" was with Wyeast 2278, Czech Pilsner yeast. I'm assuming that's close to Urquell 2001.

The siphoning could potentially be an issue, I suppose. I use an autosiphon and am always skeptical of it and most siphoning methods. I'm really considering doing a fully closed pressure ferment for my next lager.

And I always pitch at fermentation temps. Anything else seems silly.

 

[winvarin]

I used a dry lager yeast for the first time on this most recent batch. I have not yet opened the fermenter to check gravity or taste/smell. Today is day 8. I was planning on going to day 9 or 10 before checking. I am at 52F and still getting venting through the airlock every 3-5 seconds.

I did pitch warm (low 70s) but did get the beer down to ferment temps as soon as I got krausen. I was at 52F right around 18F after pitching. I pitched two packets of re-hydrated s-23 (for my gravity, mrmalty.com recommended 1.9 packs)

I'm expecting perhaps some fruity esters from pitching warm, but I had not though about diacetyl as being enhanced by the warm pitching.

Should I have noticable diacetyl when I check tomorrow night or Monday, what is the best recommendation for removing? A rest by ramping up the temperature, or krausening? I've heard that this far into fermentation, ramping up the temp and adding some fresh wort with some additional yeast will also scrub diacetyl. Have any of you tried krausening? How much wort is suggested? How much yeast? ale or lager yeast? I have a packet of us-05 sitting in the fridge now.

 

[funkswing]

Uh oh, there you go assuming. Lager yeasts can be a pain in the ass. Def. try the 2001 Urquell yeast next time. It is my favorite all-around lager yeast. Its easy. You don't even need to use a secondary fermenter with in, just "lager" in the keg before serving. You can leave it in the primary for easily 3-4 weeks.

If your siphon is clean then you don't need to go to the extreme of closed fermentation. Siphoning is fine, unless you are getting a "head" on top of your beer when siphoning.

Lagers just have a different set of problems compared to ales. The yeast just lets more flaws thru than a ale yeast, which is fruity and stays in suspension longer.

 

[funkswing]

win - I think you should just wait and see if you even have diacetyl first. But pitching warm generally always produces it, but that doesn't mean you will taste it tomorrow. Sometimes it creeps up on you.

I would plan on doing a d-rest. About 10 days is a good time to do it if you don't want to check the gravity (again, poor sanitation can create diacetyl, too). Just take it out and let it warm up to the mid 60's for 2-3 days, then continue from there.

 

[WVbrewer]

As stated a few posts back, I pitched some notty on my keg to see if it would clean up the diacetyl. Sucess! There is a hint of the D, but nothing like the butterscotch bomb this beer was. I hope it clears and recarbs by next Saturday. Thankfully it wasn't a contamination issue.

 

[winvarin]

win - I think you should just wait and see if you even have diacetyl first. But pitching warm generally always produces it, but that doesn't mean you will taste it tomorrow. Sometimes it creeps up on you.

I would plan on doing a d-rest. About 10 days is a good time to do it if you don't want to check the gravity (again, poor sanitation can create diacetyl, too). Just take it out and let it warm up to the mid 60's for 2-3 days, then continue from there.

OK. That brings up one more question. What to do after the D rest. So let's say I am in the neighborhood of 80% tomorrow and plan to do a 3 day D rest at 65F.

At the end of the D rest, if I am at 100% attenuation, then what?

For ales, I usually leave it on the primary for about 3 weeks to ensure the yeasts sufficiently scrub up after themselves. At the end of the D rest, do I just drop it back into the mid 50s for another week to 10 days? Or do I rack off the yeast and proceed straight to lagering?

I ask because I had a couple of ales get hit with acetaldehyde earlier this year until I went with the longer primary period. I traced it back to the fact that I was fermenting my ales under refrigeration and had slowed everything down significantly from room temp ferments.

I certainly don't want to re-introduce a flaw like that by taking the lager off the yeast too soon.

Will the D rest itself be sufficient to clear up fermentation by products. Or will a few days back in the proper temperature range be needed to let the yeast finish their job?