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So THAT's what diacetyl tastes like!

Discussion in 'Homebrewing' started by good_gracious, Dec 6, 2012.

  1. Its always striking to me (mainly because I'm forgetful) how often the answer in these cases is "let it sit for a while so the yeast can do their thing." These organisms are pretty awesome if you ask me
  2. Never tasted D in a homebrew...never...but have experienced it infrequently and always in a commercial brew...some from very reputable breweries.

    Aldehydes (green apple) seem much more common in homebrew for some reason.

    1-2-3 would be a good rule of thumb if it were 3 (weeks in primary), 2 weeks at room temp, and 1 month in keg for most beers...IMHO
  3. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    My recollection is I picked it up in the India Ale, as I've had that most recently. It didn't disagree with me, though. I just picked up Samuel Smith's Chocolate Stout, encouraged by another thread. I'll see if I can pick it up in there, but I suspect the chocolate character will obscure it.
  4. yinzer

    yinzer Savant (385) Pennsylvania Nov 24, 2006

    I'd go with [if no dry hopping] 3 (weeks in primary), 2 weeks at 31*F, and 1 month in keg for most beers. Or maybe switch the last two.
  5. No dry hopping! : )
  6. Unless you are making a high ABV beer or adding fruit, no reason to go over two months before serving.
  7. True for a hefeweissen or LOW abv beer..but most beers will benefit with a litttle patience...maybe even the hefe and low ABV beer, IMHO.

    Edit: as for the high ABV beer...usually minimum of 6 months for me...drinkable at 2...but so much better at 6.

    High ABV Edit: The big variable it seems is packaging...if you have ways to slow down O migration (kegging and purging), all the timetables change. Cheers
  8. It really depends what benefit you get from the extended aging. Some malty beers benefit from extended aging where the malt flavors will meld better. Certain yeast strains like Dupont need extended aging. However, if you are experiencing rough yeast character there is a problem in your fermentation process and you are using time as a proxy for fixing a problem. There's no reason why a hefeweizen or even a 7% IPA needs two months before it's reached the proper time.

    The appropriate time for a beer to be ready to drink is always dependent on the particular beer but that sort of bumper sticker rule that beers need to sit in primary for a month and similar nonsense is bandied about the internet a lot but it's just wrong. If it were even remotely true cask ale would be undrinkable and you wouldn't see good craft brewers rolling out beer 2-3 weeks after fermentation.
    jlpred55 and NiceFly like this.
  9. One aspect that was somewhat discussed in this thread is: when is homebrew ‘done’?

    I think that most folks would agree that at a minimum the fermentation is complete when the yeast has consumed all of the sugars that it can metabolize; i.e., the final gravity is reached. A number of BAs keep the beer in the primary for a period of time after the final gravity is reached (or you could transfer to a secondary vessel). The timeframe beyond when the final gravity is reached is a conditioning phase. John Palmer is an advocate of bulk conditioning (i.e., conditioning either in the primary or a secondary). There is no doubt that further conditioning can benefit the beer; during this timeframe the yeast will metabolize compounds such as acetaldehyde, fusel alcohols and other unwanted compounds (presuming they are present in the immature beer).

    In another thread I made an argument that conditioning can occur in the bottle equal to bulk conditioning. I have no scientific papers to back up this claim but it has been my personal homebrewing experience that this is true. When I first started homebrewing back in 1995 the instructions from my LHBS was to bottle when the fermentation is complete:

    “It will take four to seven days for fermentation to be complete, although it may take a bit longer. You may bottle when the water level in the airlock is even or when the hydrometer reading is the same two days in a row.”

    I am sure that the majority of BAs would recommend that the airlock not be used to evaluate the completion of fermentation but instead use multiple hydrometer readings over a few days to confirm that the final gravity is achieved.

    So, for many years I would bottle when primary fermentation is complete. I would notice that most beer styles would improve with additional time in the bottle. For example, a given batch may reach peak flavor at 4-5 weeks within the bottle.

    Over the past number of years I have become more relaxed in my homebrewing schedule and I will let the beer sit in the primary a period of time beyond when fermentation is complete. Sometimes 7 days beyond completion of fermentation. I still notice that my beers benefit from aging in the bottle beyond the two week carbonation timeframe.

    I should mention that I have never conducted a secondary for my ales.

    I suppose this is a long winded way I stating I was never a proponent of the 1-2-3 rule. I am of the opinion that quality homebrewed beer could be made via a 1- 5 rule:

    · 1 week of fermentation assuming that final gravity is achieved
    · 5 weeks of time in the bottle.

    Cheers!
  10. Nothing here to argue with...I will use "time as a proxy" and "bumper stickers' to encourage new brewers to make better beer than if they rushed it.

    ps... 3 weeks does not equal 1 month in primary...and 2 months does not equal extended aging
  11. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    Jack,
    I consulted Jamil Zainasheff on this topic several batches ago (my first lager, Herr Professor, an Oktoberfest brewed in 2009 to celebrate my renewed teaching contract) and he seemed to agree that I could accomplish the same thing by lagering in bottles (after priming) vs. bulk conditioning (followed by priming). The question arose because I wondered if I would need to add yeast after bulk conditioning in order to bottle prime. JZ's advise was to bottle prime first, then lager. He suggested that bulk conditioning was bunk, and that conditioning ought to be able to happen properly regardless of volume. I'm paraphrasing, but I feel like I've captured the essence. You are not alone in your opinion on this topic.
    PW
  12. VikeMan

    VikeMan Advocate (740) Pennsylvania Jul 12, 2009

    They are awesome. But I think our collective tastes (as a species) have probably evolved right along with what yeast do naturally. So when healthy yeast pitches are allowed to do their thing, we like the result. If there would have been an evolutionary advantage for beer yeasts to produce and not clean up (say) asphalt, we'd probably be striving for it in our homebrews today.
    pweis909 likes this.
  13. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    Three cheers for coevolution! Hip! Hip! Hooray!
  14. Well fortunately for us yeast have a much shorter life cycle, so perhaps they can evolve much more quickly than we do. In that regard I'd think we would have a lot of control over what constitutes "good" qualities in yeast strains. This is especially true with all the advances in in microbiology/genetics/etc of late. I don't want to downplay how hard that job is, but maybe if we as customers decide we REALLY want a yeast strain that generates, I don't know, a bacon flavor, they could make it happen in a relatively short time frame compared to the human evolutionary cycle.
  15. barfdiggs

    barfdiggs Savant (420) California Mar 22, 2011

    Heresy!
  16. yinzer

    yinzer Savant (385) Pennsylvania Nov 24, 2006

    I'm not sure if this will ad any clarity, but some of you might remember about three months or so ago I posted a video of one of my carboys basically being a volcano with a steady stream of foam coming out of the top. It was a clone of Chad Yakobson's Baltic Brett Porter. I'm still not too sure why it had the foam snake. It was fermented low, I think it was the dark roasted malts.

    But since it was determined to be done, it's been crashed to freezing, warmed, forgotten about, chilled, warmed, chilled ,etc. I don't own a kegerator so it's been at my beckon call of when I wanted to drink it.

    Now it was never a bad beer. After all, this random couple liked it:

    [​IMG]

    I think that's a key. There are things that you can not over come. But every beer and every style will have certain challenges. But it's really this beer is tasting it's best now. And it was off the yeast cake long ago.

    Yeah, I had a good point when I started. Time to hit a corny.
  17. NiceFly

    NiceFly Savant (375) Tajikistan Dec 22, 2011

    Looking at that gentleman's sweater I would say his taste is highly suspect;).

    Anyway, a few comments on other comments, and unfortunately they have nothing to do with diacetyl:
    I use WY1968 all the time and never have attenuation problems. Then again I mash at 148F and have been known to use sugar from time to time.

    Just because you make a starter does not mean it is the right amount of yeast. For a long time I was making the occasional shake starter and really thought I was doing everything right. Then I tried my beer side by side in a big homebrew exchange and realized I had just gotten my ass kicked and the reason was fermentation. So I worked on that aspect and got a stirplate and I have had much better beer since then.

    I agree that some beers get better with time, but that does not mean they should taste bad early. A few exceptions but even bigger beers can taste just fine in a week or two after brewday. Provided you keg and such.

    So to bring this back around to the topic at hand if you have a fermetation off flavor then you have a fermentation problem. Sounds pretty obvious when you say it out loud. Time will fix some of those problems, but it is better to look at the source of the problem a little closer and address it there.

    Amen. /end sermon.
  18. I knew Thomas Jefferson was into fine ales, but I had no idea he had such outstanding fashion sense.

    I'd agree that most beers seem to get better with age (mine do least), but I often don't have the patience to see how good it could be. Most things I brew are at least halfway gone by the time they reach the sweet spot, if I'm lucky. Often i'll keep one or two bottles behind, taste one some time later and inevitably wish I had saved the whole batch for that long.
  19. Is that deKulminator?
  20. If I could rename the title of this thread it would be: I AM SO STUPID.

    Pulled yet another butterscotch-esque sample from the primary, and I'm currently at 8 days for those who are counting. I kept thinking, "why is this happening? I've never had this issue!" Then I remembered: when I sanitized the yeast vial prior to pitching for the starter, I used hot water in the sanitizer! I tend to do this all the time for my equipment, maybe because I'm neurotic and think chemicals will do a better job sanitizing at higher temperatures (we can save reaction rate discussions for another day). Anyway, this high initial temp for the starter (I'd quantify it at ~90F btw) has apparently completely dominated the taste profile for this beer. I'm really shocked this is the case since that little vial is so diluted in a 5 gal batch. I should mention that attenuation is apparently fine, however, right at the expected 1.014 from a SG of 1.062. It has stabilized over my last two gravity readings, today and 3 days ago.

    ANYWAY, pwies909 mentioned making a new, smaller starter with a clean yeast and repitching to clean up the diacetyl. Any thoughts on this? More yeast and time and dme are of no concern to me, I'd rather the beer taste good and not have to call it honey nut butterscotch brown.
  21. Guess I could have quoted it to be clear about what I was thinking of doing.
  22. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    In the last issue of Zymurgy, Neva Parker from White Labs discusses fermentation off-flavors and recommends pitching some act yeast to clean up problems related to diacetyl and acetaldehyde. I didn't make it up. :)

  23. Peter,

    Good_gracious stated: “Pulled yet another butterscotch-esque sample from the primary, and I'm currently at 8 days for those who are counting.” Do you think his yeast is now non-active at 8 days? Is there a need to add more yeast at this point in time?

    Cheers!

    Jack
  24. Even if you did make I'd up yourself I'd probably try it anyway since it sounds like a reasonable last option. The fact that it was published makes it even better
  25. barfdiggs

    barfdiggs Savant (420) California Mar 22, 2011

    It works. Referred to as krausening IIRC. Done it for a beer or two that had some d-issues and it cleared it up. Just make sure its actively fermenting wort your throwing in.
  26. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    You make a good point, Jack. Good-Gracious's beer is still pretty young (it sounds like it was brewed on Dec. 2), but it also sounds like his yeast hit terminal gravity and might be petering out. He might stimulate some already present yeast into activity with some gentle swirling and increased temperature. If he's on a time table to get this brew finished fast, I would say pitching some frothy active yeast is the way to go.
  27. VikeMan

    VikeMan Advocate (740) Pennsylvania Jul 12, 2009

    Personally, I would never re-pitch after only 8 days based on the presence of Diacetyl. Chances are the existing yeast would take care of it. However, I'm pretty conservative about re-pitching in general, and think most of the repitching people have done was probably uneccessary.
  28. In your experience with diacetyl, can you qualify at all how much was removed through normal yeast activity? A description like "it was a butterscotch bomb at 8 days and after 2 weeks it was clean as a whistle!" would be great. I have no experience with this, but I think I'm asking a lot from my yeast friends to clean up this much diacetyl.
  29. Jack, vikeman and Peter,

    This beer is most certainly young at this point--only 8 days old. To be honest I hate to even be having this discussion so early on, considering I have at least a week of sitting on this before I do anything. In the meamtime I have been rousing the yeast and increased the ambient temp to 70. We'll see what that does. Subsequent to that I'll probably do another wlp002 starter if necessary. To the repitchers out there, does 1L sound reasonable?

    Thanks! Matt
  30. pweis909

    pweis909 Advocate (695) Wisconsin Aug 13, 2005

    My only experience with repitching to mop up diacetyl went approximately like this...
    -My lager fermented in primary for 10 days at 52F and hit terminal gravity. The gravity sample was a butterbomb.
    -I raised the temp to 63F for a diacetyl rest. I probably should have done this a day or two sooner, before the yeast hit terminal. I held them at 63F for a week and it was still a butter bomb.
    -I raised the temp to 70F for two more weeks. Still a diacetyl nightmare.
    -At that point, 31 days after first pitching, I started a conversation in the forum, got some advice from a probrewer, which matched the forum advice and my own instincts, and repitched. Then I waited several more weeks, tasted the beer, it was fine, transferred it to a keg, carbonated, lagered for another month, and enjoyed my pils about a several weeks later than I originally hoped. And it was good.

    My point is, I waited considerably longer before I decided the yeast were done, then I repitched. If I had repitched sooner, I would have been drinking the beer a little sooner.
    good_gracious likes this.
  31. “In the meamtime I have been rousing the yeast and increased the ambient temp to 70.” Are you rousing the yeast on a regular basis (e.g., once a day)?

    When I used WY1968 (the equivalent of WLP002) I would rouse the yeast daily but I started the rousing early in the fermentation timeframe (e.g., on day 3 or so of the ferment).

    Hopefully the rousing will ‘do the trick’.

    Cheers!
    good_gracious likes this.
  32. VikeMan

    VikeMan Advocate (740) Pennsylvania Jul 12, 2009

    I have yet to have any detectable diacetyl at the end of any conditioning period, whether that was a diacetyl rest (with lagers), or simply leaving the beer on the yeast (with ales) at fermentation temps. It's normal to taste diacetyl before the yeast has been given a chance to finish the job (after primary fermentation is complete)...that's just the normal order yeast does things.

    However, I can't say that I have ever had what I would call a butterscotch bomb at 8 days. It's quite possible that I have, but I don't taste every batch (or even most batches) that early. Pweis909's suggestion of pitching highly active yeast is a good one, which I think should work equally well if you wait to see if it's necessary before you do it.
    good_gracious likes this.
  33. Gracias amigos. I'll rouse daily for maybe another week, taste, and then see where to go from there. If nothing changes I'll make a ~1L starter using us05 or something else that's clean. Hope that'll do it. I'll update again once the beer is no longer so immature.
  34. yinzer

    yinzer Savant (385) Pennsylvania Nov 24, 2006

    What Neva Parker said was too, "...transfer the beer to a secondary vessel and krausen it by adding fresh, activity fermenting yeast."

    To me that translates into making a starter (yes, some will disagree with this term being used here) with a high inoculation rate (propagation is not the purpose here) into non-areated wort. Once it looks like it cooking I'd give it a shake to release the CO2 from the yeast cells. When it's like the bubbles are going to overflow I'd pitch the whole thing. Another reason not to make the starter acidic from prior aeration..

    jut my $.02
  35. Whew! I guess 2 months later it would be good to provide an update, at least for posterity.

    Abridged version:
    12/2: brewed brown ale. sanitized yeast vial in ~90F water for 30min (idiot!). OG 1.062.
    12/5: 1.020. Diacetyl!
    12/7: 1.015. Diacetyl!
    12/10: 1.015. Diacetyl! Roused yeast from 12/10-12/15.
    12/15: 1.014. Rehydrated 1 pack S-04 @ 80F for 20min. Pitched.
    12/16-12/31: Untouched (visiting family over the holiday)
    1/1: 1.014. Bottled. Diacetyl! (not as bad, but definitely still present)

    Bottles at 1/14, 1/20, 2/5 all reminiscent of butterscotch. Perhaps I'm used to it, but the diacetyl is not quite as prominent as before.

    On a related note, I tried Sam Smith's Oatmeal Stout and Brown Ale during this time. Definitely taste the diacetyl in the stout (not a huge flavor, but it's there), but GOOD GOD the brown ale was almost like a mirror image of what I brewed. It was undrinkable to me, mostly because it reminded me of my failure :(

    Maybe I'm just not meant to drink brown ales! Not all brown ales showcase this flavor to the same degree, but now it's hard for me to drink anything remotely reminiscent of this beer.

    Incidentally, if anyone has a high taste threshold for diacetyl, feel free to send some beers my way and I'll see if I can point it out for you ;)
  36. Sam Smiths has enough Diacetyl that I can get it with no problem - my threshold is medium high. The people who always say what a great brewery must be blind to Diacetyl. Just saying.
    barfdiggs likes this.
  37. For what it's worth...I've never had a problem with US-05 producing diaceytl...even when somewhat abused.

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