Diacetyl

[mckenry]

Some diacetyl is welcome in UK brews, and also in many Czech lagers. There are even breweries such as Wychwood that promote diacetyl by double dropping.

I quite like a bit myself, that's why I love Wy English Bitter 1768, run it through quickly and keg early.

In the past, talking about necro threads such as this one, a lot of brewers seem to have conflated diacetyl with DMS for some reason, maybe the use of the letter D.

:icon_offtopic: Well thanks for a new word Bribie G !

Now to use conflated in today's conversation.

 

[TheWiggman]

I did an ESB once which had detectable diacetyl in it and I could see how it could be to style. After being figuratively fly kicked in the teeth by it in a brew a mate of mine bottled faaaar too early and brewed at low temps using WLP005, it's a flavour I'm conditioned to detest now.

 

[Sippa]

Last time I discovered diacetyl (sample tasting) I left it in a d-rest until I could no longer taste diacetyl in the samples.

 

[Goose]

conflated necro thread....

I learn something every day....

 

[Bribie G]

Sounds like swollen corpses. Ah the labyrinthine intricacies of English.

 

[Tropico]

So how does one make diacetyl?

Edit: A lot of discussion about getting rid of it, so what are the reasons that is more prevalent in some brews than others?

 

[Goose]

So how does one make diacetyl?

I am very good at it. :huh:

 

[TheWiggman]

Like beer, man cannot make diacetyl - the yeast does. Many good reads out there like this one: http://www.whitelabs.com/files/Diacetyl_Time_Line.pdf

 

[Sippa]

I am very good at it. :huh:

No your not, your good at giving the right conditions for particular yeast strains to make it :lol:

Typically it is a by product of colder fermenting yeast ie. lager yeast, that's why we give lager yeasts a D rest. Actually can someone tell me if you ferment an ale yeast at its absolute lower limit of temp will it produce diacytel?

Let me rephrase that question, will ale yeast produce enough diacetyl at its lowest temp to produce considerable diacetyl?

 

[Sippa]

Don't answer that, I just read the article posted above, answered all my questions and proved my above statements mostly incorrect.

 

[antiphile]

I don't think I've ever used S-189, but I do recall a tip from Fermentis that if there is a problem with diacetyl, that it helps if you gently rouse the yeast with either carbon dioxide or nitrogen to resuspend the yeast during the D rest.

http://selma.phile.com.au/beer/PDF/Fermentis-tips_tricks.pdf (page 10).

 

[Bribie G]

I'm currently using Wyeast English Special Bitter 1768 in a batch of UK Special Bitter, but slow fermenting it at around 16 which is ambient here in my garage ATM.
Normally I put it through fast and get my nice butterscotch overtones so it will be interesting to see how this batch polishes up.

On the subject of personal taste, I once took some 1768 brewed Camerons Strongarm Bitter tribute to a club meeting. Most really liked it, and were intrigued to learn that the subtle butterscothy flavour was indeed D. However on opening the bottle, a guy two tables away shouted "ok who opened the Diacetyl Beer". :lol:

 

[yankinoz]

I use S-189 in all my lagers, which are generally malty styles for which it is particularly well suited, and usually go up to 18 for a four-day rest, or even 20 for a shorter rest.

Take a look at the following posts by Martin Kai, an experienced and highly scientific brewer of German lagers:

http://braukaiser.com/blog/blog/2012/03/13/diacetylrest-at-22-c-72-f/

http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers

Re previous comments, I'm unclear why cold-crashing would produce diacetyl. Fermentation at low temperatures, yes, but chilling a finished beer faster or more slowly?

 

[TheWiggman]

I think the point about the cold crashing is that the diacetyl-absorption function of yeast hasn't been completely utilised. More time on the yeast then cold-crashing would alleviate this. This would apply only if you cold crashed while excessive diacetyl is still present in the beer. TB's post sums it up well, would be great to have him back.

 

[Goose]

I use S-189 in all my lagers, which are generally malty styles for which it is particularly well suited, and usually go up to 18 for a four-day rest, or even 20 for a shorter rest.

For my current batch, after SG dropped to 1.011 after 9 days then raised to 19 deg C for 2 days. I did the forced D test and that showed it was still full of AAS. Had I kegged then it would have been a surefire disaster.

After 5 days of D rest I tested again and its almost gone. I'll let it go for 2 more days to be certain.

I never would have believed a D rest would take this long. At least in my case.

After the 2 day test I did do my best to agitate things up a bit, just a rocking and did not go to the extent of bubbling c02 in for agitation though I would have tried it if I could detect no improvement.

Man this yeast is one lazy sob, but when it works, its great...

 

[Goose]

I'm currently using Wyeast English Special Bitter 1768 in a batch of UK Special Bitter, but slow fermenting it at around 16 which is ambient here in my garage ATM.
Normally I put it through fast and get my nice butterscotch overtones so it will be interesting to see how this batch polishes up.

On the subject of personal taste, I once took some 1768 brewed Camerons Strongarm Bitter tribute to a club meeting. Most really liked it, and were intrigued to learn that the subtle butterscothy flavour was indeed D. However on opening the bottle, a guy two tables away shouted "ok who opened the Diacetyl Beer". :lol:

If anybody has a copy of "Microbrewed Adventures" by Charlie Papazian there is a very good read in the Introduction that describes his favourite beer of all time. "Ballard Bitter" by the now Red Hook brewing company. This beer was characterised by just the right amount of diacetyl, but given its perception as a flaw it was eventually eliminated from the beer. A big step down for Charlie in terms of appreciation.