Diacetyl in Beer

I tasted it for the first time earlier this year in a John Henry 3 Lick Spiker Ale and I wish I could un-taste it. I pick it up pretty regularly now and really makes me immediately react negatively to the beer. I most recently tasted it on draft in Helldorado. Even though this is supposed to be ok in small amounts in some styles, it's very distracting to me now and I wish I could block it out

Edit - I should clarify that the 3 Lick Spiker tasted like straight butterscotch but it was in the background of the Helldorado.

 

I am semi-sensitive to diacetyl, and yet... I actually enjoy the texture it gives some of my beer, and more-so, some of the flavour it can impart.

Having said that, if it's *not* something the brewer wanted in their product, then I'll call a flawed beer flawed, and grab another. Just to be sure, of course.

However, if the brewer decided that they want that butterscotch aroma and flavour, with a buttery, oily texture as part of their brews, then Bravo! Lets order another, to celebrate!

 

The O2 just accelerates the conversion of acetolactate to diacetyl - you have to have heat to effectively catalyze the reaction. When we set up gas chromatograph runs to measure diacetyl, we shake the samples to introduce O2 and incubate them at 75C for 50 minutes in order to make sure we fully convert all precursor to diacetyl so we get the total diacetyl amount, not just the free or perceived diacetyl.

Otherwise you're correct. If you taste diacetyl in beer, it's due to those 3 reasons. There is a chance that you have an excessive amount of precursor that hasn't been converted to diacetyl yet, but it's because primary fermentation was cut short.

 

I'd never thought of it this way before, but I think it's a perfect description. I've had beers that, for all intents and purposes, were not objectionable to my palate, but still prevented me from truly enjoying the beer based on the perception of diacetyl. When mild, diacetyl seems to have a flavor profile that one might find enjoyable--even in a beer. Is butterscotch really so far removed from some of the caramel, molasses, brown sugar, candied fruit profiles that many beers sometimes contain? And yet, my brain knows that this flavor that may be pleasing to my tastebuds is "wrong". My brain's objective rationality seems to override the subjective sensory perception of the beer in question.

This recently happened to me with Clown Shoes' Crasher In The Rye. I drank it with the strange sensation of not enjoying the flavor of the beer while simultaneously not being able to really identify why I wasn't enjoying it--it tasted "fine", so to say.

At any rate, this entire thread has been illuminating, as I had many of the same questions as OP posed. Thanks to everyone who has shared their knowledge/experience.

 

Kara Taylor of White Labs gave a talk on diacetyl, and said it is O2, higher heat, and lower pH. So finished beer that has O2, and gets warm will form it.

 

apologies if these have already been answered... i haven't read through everything

you're talking about 2 different things here.

diacetyl is an intermediary product of fermentation. sugar's transformation into alcohol and CO2 takes many steps and yeast doesn't always finish the process. diacetyl is one of those by-products of incomplete fermentation. after yeast have munched through all the sugars, under the right conditions they will scrounge around for the crumbs they left behind and complete their fermentation. one of those conditions is that there is active yeast. saccharomyces will only go on for so long, brettanomyces will keep the party going for a lot longer.

one way that diacetly can also worsen over time is if you don't have any active yeast to clean up and you have an infection - like pediococcus - that produces diacetyl. that's why sour beer brewers always pitch brett with pedio.

yes - pedio. it's slow-acting, can take months to do its thing.

 

This is why I usually assume a packaged beer 'passed' the sensory board, even if I get a ton of butter; how could it pass if they are sensing the same things I am sensing? If there is AAL, add in the oxygen from packaging, the heat from sitting in a warehouse, and there you go.

 

Another reason for the importance of very, very low levels of O2 during packaging.

Hopefully commercial breweries read these threads and take appropriate action.

Cheers!

 

Is there a good place to ask about diacetyl in certain beers? I had one recently and would love to see if others have noticed the same. I know I can read reviews, but also wanted to have a discussion...any ideas?

 

i tend to find it almost only in ipas, i just had a buttery ipa last night. so gross

 

http://www.beeradvocate.com/community/threads/diacetyl-beers.195922/

Cheers!

 

I was told that Sam Adams leaves some diacetyl in Boston Lager to increase the perception of fullness. Whether or not they still do still is up for debate. Pilsner Urquell does the same, supposedly targeting around 100ppb.

As for my taste, I prefer beers without a noticeable diacetyl character.

I stopped drinking Deschutes as I get a low level diacetyl flavor in most of their beers. Not surprising since they are now using Ringwood.

 

Ringwood can produce very clean beers (no perceptible diacetyl) as long as the brewery provides sufficient tank time to permit the yeast to process the diacetyl that was formed during primary fermentation. Some folks refer to this as conducting a diacetyl rest. I have a local brewpub that uses the Ringwood strain as their house ale yeast and by following proper fermentation methods their beers have no perceptible diacetyl (I had a conversation with the brewer on this topic).

When and why did Deschuttes switch their yeast strain?

My local brewpub likes to use Ringwood since it drops bright and there is no need for filtering but the 'expense' is additional tank time.

Cheers!

 

That's funny; I heard the opposite about certain UK breweries, including Meantime.

They're getting social media reviews of having diacetyl when it's actually the rich, buttery character of Maris Otter - to the point where they're cutting the MO in favour of other pale malts.

(No link to hand, but Google returns lots of threads.)

 

Not only can concentration change the character of something as you suggest, sometimes people also just perceive things differently.

 

I would call B.S. on that actually... I use a lot of Maris Otter, mostly Thomas Fawcett, but occasionally Crisp. I've used it in barleywines with 5 hour boils and I've used it in English Milds and just about everything in between and I've never gotten a buttery flavor from it. I have tasted buttery flavors in some light crystal malts and I frequently think that I mistake Carastan for diacetyl in IPA's. I'm very sensitive to diacetyl and I don't particularly care for a lot of caramel malts because of the similar sweet flavor.

 

And reportedly something like 25% of the population is 'blind' to diacetyl in beer. I personally know an assistant brewer at a local brewpub that is incapable of tasting diacetyl in beer. The head brewer can taste diacetyl and he has to perform the function of final quality control before declaring the beer is OK to be served at the brewpub.

Cheers!

P.S. I attended a tasting presentation at last year's National Homebrewers Conference and one of the test beers provided to the audience was a pale beer spiked with diacetyl. The presenter mentioned that he does not perceive either butter or butterscotch but a totally different flavor all together (he mentioned the flavor but I can't remember it now); he knows that when he perceives x that others are perceiving butter/butterscotch.

 

Weedy I have homebrewed with Marris Otter a number of times and I too have never perceived butter/butterscotch in those beers.

I too am pretty sensitive to diacetyl and mostly I am not a fan of this flavor. I must confess that I personally do not object to the level of diacetyl in Pilsner Urquell. I recently homebrewed a Tmavý Ležák (Czech Dark Lager) for a second time and I am not picking up any diacetyl in that beer (I use WLP802 Czech Budejovice Lager Yeast for this beer).

Cheers!

 

For those in the Twin Cities, MN area, Tin Whiskers Brewing is conducting an off-flavor training. If I am reading the Facebook post correctly, it is being held next Tuesday, March 29.

 

I've seen this before but try feeding in any values regarding diffusion of oxygen through a tightly crimped cap liner and it's infinitessimal. Oxygen in the bottled beer is a different matter