diacetyl in lagers

General Homebrew Discussion
1

My red lager has a caramel and almost butterscotch like sweetness to it. I know that butterscotch is usually associated with diacetyl. What other signs should I be looking for?

The beer finished with a higher FG than it should have (discussed in another thread) so at first I assumed the sweetness was related to that and maybe the fact that I used 100% Red X for the first time and am not familiar with it’s flavor profile. It wasn’t until the other day that I realized that it might be diacetyl. I did a diacetyl rest at 62F for a couple of days. I poured one the other night and that character seemed to have faded a bit but it is still pretty prevalent.

Do you think this could be the combination of high FG (1.015), Red X, and a bit of diacetyl?

2

Two step process:

  1. Pour yourself a sample of standard commercial American ale.  Swoosh it around in your mouth.  With your tongue, feel around inside your mouth, especially the roof of your mouth.  Okay… that’s “normal”.  That’s the baseline.

  2. Pour a sample of your lager.  Swoosh it around in your mouth.  With your tongue, feel around inside your mouth, especially the roof of your mouth.  Does it feel a lot more slick or slippery in there this time?  That’s diacetyl.  But if you go back and forth and you can’t detect it in the mouthfeel, then you might not have diacetyl.  You might still need a judge to know for certain.

Hope this helps.

3

might be just me but its always been butter…not butterscotch from D.  it should stand out pretty much like imitation butter flavor…hard to miss and for me, I pick it up instantly in beer even in small amounts

redx maltiness could be it…especially with higher FG.

4

I agree with all of this.  If you detect a “popcorn” flavor, that can also be a sign of diacetyl.  But again, unfortunately, there are malts (and actual corn) that can also fool you.

5

Thanks dudes. Definitely not getting the artificial butter thing. After the diacetyl rest, I detected no diacetyl in the hydrometer sample. I have brewed a couple of batches with S04 that had diacetyl but that was before I was ramping the temperature up toward the end of fermentation.

Overall, I just didn’t brew a very good beer which is sad  :frowning:

6

thats good. keep in mind that while not detected initially, from what Ive read there can be precursors for it becoming noticeable at some point after fermentation…IIRC when O2 interacts with the beer.

also, an infection can do the same IIRC.

butterscotch certainly is a flavor that can come from the malts used.

7

Good to know. I will just have to see how it develops with some age and hopefully it improves a bit. I have never brewed a beer similar to this one.

I probably should not complicate matters but I also recall almost a fruity, banana type thing going on. I used palisade hops which I have never gotten that character from. It certainly has an interesting combination of flavors. The yeast was W34/70, accelerated lager schedule starting at 52F. Sounds like I need to do some sampling tonight…

8

I’ve definitely seen that effect once or twice.  Not every time but sometimes.  No diacetyl at bottling, then big diacetyl for a couple weeks, then another week or two later it’s gone again permanently.  Must be the yeast interacting with oxygen like you say.  (I bottle condition; I do not keg, so I don’t know if keggers get the same exact effect.)

9

This is sounding more and more like a stale extract beer to me.  Did you use any extract at all in this beer?  If so, wink-wink, yeah, it is very likely the dreaded “extract twang”.  If not, then nevermind!

10

100% Red X malt

11

If you want practice tasting diacetyl in a lager, RedHook Pilsner is the biggest D-bomb I’ve ever had. I get it in most of their beers, but the Pilsner is the worst offender of them all.

12

if interested in reading, this explains in simple terms what I likely did a poor job of in my previous post.

also tells you how to do a proper test for D in finished product.

13

Oh.  Guess I need to learn to read!  Yeah, that’s probably it then.  Just a very caramelly malt I guess (I haven’t used it but I can guess).

14

Good article. Thanks for posting.

15

There is a fix for diacetyl. You can make a starter 10% the size of your batch and pitch it into your current beer. Let that ferment out and the new yeast will absorb the diacetyl.

Of course, this will through off your hops a bit but if the beer is undrinkable it’s an option.

16

Yep, it’s called “krausening” and it works well.  Pitch when it’s actively fermenting.

17

Supposedly, palates vary wildly in ability to taste diacetyl. I’ve met many a judge who say they can’t perceive it. You could be in that camp.

As far as fixing it, simply sprinkling US-05 directly onto the beer works better for me than kräusening. I’m not sure why.

18

I am not sure if transferring this out of the keg and adding more yeast is in the cards. I already added additional yeast in attempt to drop the FG more. I had a sample earlier tonight and I get strong toffee/butterscotch but no artificial butter. I will try to test for it soon by heating a covered sample.

19

How is the even acceptable in ANY commercial brewery?

20

It is common in Czech Pilsners - the Czech lager strains develop it even after an extended D-rest.  So, it is part of the expected flavor profile.  A few ale styles permit it under BJCP styleguidelines, but even then it is typically not desirable.