Odd Off-Flavor in Lager

So I am fermenting my first lager and I am concerned about an off-flavor that I have detected in my gravity samples. The two samples I withdrew were awful, to say the least.

Part of the flavor is cooked, buttered corn. I take that as diacetyl. (The beer is at a diacetyl rest right now).

The other component is a sharp chemical flavor. It kinda burns and is at the forefront of the flavor profile. It hits you the moment you take a sip.

I know that the diacetyl will probably be metabolized by the yeast, but the sharp chemical flavor bothers me. Could it possibly be my hop's flavor clashing with the diacetyl? It worries me that it could be a wild yeast infection producing phenols.

For what it's worth, I sanitize with Starsan and use RO water strictly.

edit: I am fermenting with Saflager S23 at 52 F. The OG was 1.050 and it's at 1.008 right now. It's been ramping in temperature for the past two days and is at 64 F right now.

Is it possible that the chemical flavor is sulfur? A lot of lager yeasts throw a lot of sulfur before cleaning it up, along with diacetyl, later in fermentation.
BTW, cooked corn can also be oxidation. A lot of pilsner malt has some of that flavor in the background, though, without there being a problem.
Plus, early samples often taste nothing like your beer finally does.
Relax and wait, and see what it turns out like. Be sure to give it time, and lager it well after fermentation has finished.

Cooked corn would be dms from boiling with the lid on or not vigorous and or long enough boil. Pretty sure the yeast won't absorb that. Not sure about the chemical flavor but lagers can be kind of weird if sampled early, the lagering phase helps a lot. Lager it for a while and at worst you night just have a batch of rolling rock.

Sounds like diacetyl and DMS is a very young beer. The d rest will take care of the former, the latter won't go away.

The only thing that I can think of that may have produced DMS is boiling for 60 minutes instead of 90.

I even used pale malt, boiled in an open pot and chilled below 80 within 15 minutes. I am puzzled if it is DMS.

I was thinking that the second off-flavor was sulfurous too. It's really sharp and unpleasant. I also sensed a similar smell coming out of my airlock during fermentation.

It was disappointing to taste such nasty gravity samples. The ales that I have fermented never tasted this weird even at an early stage. I guess that's just how lagers are.

Could it just be really intense diacetyl? Maybe just artificial butter and not buttered corn? It's so hard to say w/o tasting, and even then, the beer's so young. Honestly, let it ride, at least the young flavors will go away and if there's still issue you can troubleshoot.

organicrust said:

The only thing that I can think of that may have produced DMS is boiling for 60 minutes instead of 90.

I even used pale malt, boiled in an open pot and chilled below 80 within 15 minutes. I am puzzled if it is DMS.

I was thinking that the second off-flavor was sulfurous too. It's really sharp and unpleasant. I also sensed a similar smell coming out of my airlock during fermentation.

It was disappointing to taste such nasty gravity samples. The ales that I have fermented never tasted this weird even at an early stage. I guess that's just how lagers are.

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Sulfur is a normal byproduct of a lager yeast. This will disappear during the lagering process. It's not unusual for the fermenting room/chamber to be filled with this smell and high in the tasting sample.

Greetings from a fellow Gainesville resident.

Post your recipe and we can see if its the hop flavors clashing, but I doubt it. Could be DMS, diacytl, sulfur or all three. How old is the beer? Young lagers can be funky, but I wouldn't say chemical flavors are normal at all.

Yeah, the diacetyl is reduced somewhat, but it still has a way to go.

I'm not sensing the chemical flavor as much--I feel that it may have been a volatile sulfur compound that is now being off-gased at the higher temperature rest.

I have no idea how to describe the flavor, but perhaps "chemical" is too harsh. It's kinda musky but sharp and it clashes awfully with the buttery diacetyl.

I am pretty sure that some of the flavor is my grain bill, which is 92.3% 2-row, 5% Munich and 2.6% Carapils. I think I can taste the Munich under the diacetyl.

Perhaps the sharp flavor is due to my hopping; I used Sterling exclusively, for about 30 IBU, mostly late additions. I definitely taste the Sterling character in there somewhere.

It's been about 2 days into the rest and it still tastes buttery. Should I try krausening it?

The "chemical" flavor sounds like potentially an infection, or maybe chlorophenol.


Cooked corn does really sound like DMS. It is the classic description of DMS, although other sulfur compounds can give you similar flavors.


What temp are you doing your rest at?

For the rest, I have ramped the temperature to ~65F. It took about two days to get there and I started a little late (when the reading was 1.010).

I don't think it's chlorophenol because I use RO water strictly and Starsan to sanitize. I hope it isn't a wild yeast infection; Florida is especially bad in this regard. I read that starsan does a poor job at controlling yeast cells, so this is a possibility.

Right now, I really feel that it's the character of the hops clashing with the strong diacetyl present. My gravity sample today was a little more tolerable, so the rest is doing something. I'm not giving up on this beer yet.

Tomorrow, I'll probably boil up a small DME wort and pitch yeast siphoned from the bottom of the carboy into it. Once that's at a high krausen, I'll pitch it into the fermenter in hopes of scrubbing the rest of the diacetyl.

I like that idea, when in doubt about yeast (off) flavors, throw active yeast at it. With any luck you can get them to consume some of it. If it is DMS, and Weirdboy has a point about it soundling like DMS is in there, nothing'll really consume that. I remember reading you boiled uncovered, so that's not it. How vigorous was the boil and what was your base malt (manufacturer and type)? Those could be two culprits in DMS, even if you did have an open kettle.

So...... How'd it turn out??????

Ultimately?

A little too fruity for a true lager and a little too bitter for a Kolsch, but I can't taste any weird off-flavors anymore.

I can't say that I'm a fan of S-23 and I wouldn't recommend it to anyone. Just bite the bullet and get a liquid lager yeast (or 34/70, which is good, I hear).

In the meantime, I've brewed three more lagers. With this experience, I now believe that what I was tasting was mostly sulfur from the yeast. It subsided in each lager with a 60F rest followed by lagering.

I ask because Iam in the middle of my first lager. My d-rest took place 4 days after I pitched. I did that based on my gravity reading. It rested for like 72 hours. Its now in the laver phase -42* for the next 2 months, at least. Weird flavors with every gravity reading. My thought is that the off flavors are the liquid mexican lager yeast. Only time will tell...... nice work

Lagers can just taste/smell downright weird until they're done. Lagering will take care of a lot of those fermentations smells and flavors and clean up the beer. If you pitched enough yeast, fermented cool and did a d-rest, after lagering your beer should taste more like a finished lager.

Well, i am nervous about all of that: Did I pitch enough? Did it ferment long enough (4 days seems real short)? Did it d-rest long enough, or even too long? All I know know is that I cant change anything I have already done. I suppose the longer it lagers, the better chance that off flavors will go away. I know, I know, RDWHAHB!!!!! Problem is I cant have a home brew until June, at least....

Organicrust, my first two lagers were an Amber Bock clone with Saflager S-23 and a Schwarzbier German black lager wih 34/70 (bohall grain). Both cleaned up real nice and I had some of the same observations/concerns you had. When all was said and done, here was a flavor in the Amber Bock that it was determined at my LHBS shop as the S-23. It is so unpleasant to me, I'll never use S-23 again.