What Does Diacetyl Taste Like?

[Aleosaurus cervisiae]

Can anyone enlighten me about diacetyl? What does it taste like and how does one recognise it in a lager?

 

[jbumpstead]

Can anyone enlighten me about diacetyl? What does it taste like and how does one recognise it in a lager?

Tastes like butterscotch, and hard to explain mouthfeel - slippery, oily, slick I guess is what you'd call it.

Cheers,
Justin.

 

[ChrisECarpenter]

the classic really dark yellow, over-oaked & malo-lactic ridden chardonnays of the 1980s/1990s were fullllll of diacetyl.
not sure if that helps but that's something most people I know have a (bad) memory of.
Chris

 

[Aleosaurus cervisiae]

Thanks. When you say malo-lactic, does that also imply sour/acidic?

 

[RobH]

Thanks. When you say malo-lactic, does that also imply sour/acidic?

No, I'd say "buttery" ... and a quick google link to wikipedia seems to indicate that's right ... http://en.wikipedia.org/wiki/Malolactic_fermentation

[edit] I'll add that I have never heard of Malolactic fermentation in reference to beer before ... so I am guessing it is being used here more as an exmple of what a similar taste might be (to diacetyl)

 

[brett mccluskey]

The next time you go to see a film at a cinema,take a good smell of the popcorn as you go in ....mmmmm popcorn :icon_drool2: That's Diacetyl (actually the butter,not the popcorn).From the BJCP exam study guide ,....Diacetyl
This compound is responsible for an artificial butter, butterscotch or toffee-like aroma and taste. At low levels, it may also produce a slickness on the palate. A significant number of tasters cannot perceive diacetyl at any concentration, so every judge should be aware of his or her limitations. Diacetyl is a fermentation by-product which is normally absorbed by the yeast and reduced to more innocuous diols. High levels can result from prematurely separating the beer from the yeast or by exposure to oxygen during the fermentation. Low FAN levels or mutation may also inhibit the ability of yeast to reduce diacetyl. Note that high fermentation temperatures promote both the formation and elimination of diacetyl, but the latter is more effective. For that reason, lager breweries often employ a diacetyl rest, which involves holding the beer in the 50-55 F range for a few days after racking to the conditioning tank. Diacetyl is also produced by some strains of lactic acid bacteria, notably Pediococcus damnosus. Low levels of diacetyl are permissible in nearly all ales, particularly those brewed in the United Kingdom, and even some lagers, notably Czech pilseners.

 

[Aleosaurus cervisiae]

I thought diacetyl rest shold be around 20C. 50-55F would be around 10-12C

 

[Cocko]

Something I can actually post an opinion on..

Diacetyl taste like butter scotch lollies... Not like when they say Cascade is 'floral' so it is not a general sort of reference like that...

My 3 experiences with a diacetyl brew have been, that is butter scotch! dead set... Not 'buttery' or I can taste a little butter tone... it is butter scotch!

Had a little in an ESB once and it made it awesome, I wish I could do it every time with that recipe and to the same amount but apparently you cannot control it to that degree on a HB level... Not sure, if you can please let us know how!

Anyway, thought I would post as post counts are important to ones ego!

BTW: It does fade a little with ageing but will be underlying tone for a fair while.

 

[argon]

I thought diacetyl rest shold be around 20C. 50-55F would be around 10-12C

As a rule of thumb, do your d-rest at or slightly above the highest temp your brew has been at. Also, only perform a d-rest if you taste dacetyl in your samples... No need to do it if your palate can't detect it. Let your senses guide you.

 

[matthendry]

I could never pick Diacetyl until I did a beer judging course in the 90s with the Eastern Suburbs Brewers Club and drinking lots of Schaers lager that was known to have a high concentration of Diacetyl on some brews .

I have to be careful now evaluating beer becuase my palate is now very sensitive to Diaacetyl .

It takes like fake butter like butter spray at high concentrations and butterscotch at low concentrations which is suitable in some styles .

And at worst Rancid Butter when its caused by some sort of infection .

 

[Bribie G]

Czech Pilseners may contain a trace of diacetyl to style, also many UK Bitters. I like diacetyl in a Uk and have ordered a couple of Wyeast 1768 which do it to me every time. Basically if you run anything through too fast and furious you can get D, depending on the yeast. Even got it in an Aussie Lager on S-189 last year.

 

[Bizier]

I love it in ales at very low levels, because I think it is kind of like a background ice cream note which rounds out the mouthfeel and lubricates the beer on the way down. If it is noticeable in the flavour, I don't like it at all.

I had BREZNAK (sp?) Lager a few years ago and it was so butterscotch-like it was quite unpleasant.

 

[Siborg]

buttered popcorn all the way. Best (or worst) example of it is Grand Ridge's Pilsner. Had it on tap once and could smell the popcorn before I even picked up the glass... I must say it tastes way better if you "wet hop" it with some fresh hop flowers.