Diacetyl Rest Temperature and Time?

I do 65F-68F for a couple of days. I start moving the temp toward that range when attenuation is almost finished.

 

I will do at least 68 F for at least 2 days. After that point, I'll taste - if I sense any diacetyl (this does occasionally happen) I'll keep it there for a bit longer. If the temp climbs a bit past that point I don't worry too much either - the fermentation should be done by then and any damage has already been done.

 

2 days at 65 to 68F. It helps if you have 1or 2 Plato left to the FG, as the yeast speed up fermentation and scrub out the sulfur, along with with the Diacetyl reduction.

 

When my airlock gets one bubble every 15-20 seconds I raise the temp to 65-66 degrees for two to three days. Then I'll get the beer back to fermentation temperature till keg time. Good luck.

 

~60f. I usually bump my temp up 10 degrees gradually from my ferment temp (49-50f) towards the end when activity slows down to ensure max attenuation. I've only done lagers with WL 830 tho and haven't ever experienced diacetyl. Pitching cold and proper pitch rate should keep diacetyl at bay. Maybe other lager yeasts are bigger diacetyl producers than 830 is?

 

Diacetyl production/retention is both process and strain tendency dependent. And it can vary from batch to batch in spite of doing everything 'exactly' the same. Be wary of anyone who says that they never do diacetyl rests and never get diacetyl, across a wide range of strains. Taste sensitivity to diacetyl also varies from person to person.

 

Hmm, I've used 2124 (equiv to 830) and had some diacetyl issues... Wyeast's website says "
A thorough diacetyl rest is recommended after fermentation is complete."

Vike beat me to it also - diacetyl detection is very taster dependent - I know I am personally extremely sensitive to it.

 

@VikeMan @mattbk yea I've never came across diacetyl that I know of. So I'm not sure how sensitive to it I am? I always ramp my lagers up to around 60f towards the end and often don't taste the beer while its early in on the ferment. Maybe ill have to do more frequent sampling of my lagers early on to see if I can get a taste of the butter to at least get an idea of what it's like.

Any commercial beers with a touch of diacetyl??

Edit* my early on ferments usually smell like farts and spoiled eggs with 830 so I hope my gag reflex is strong enough to endure the sampling.

 

Samuel Smith's Oatmeal Stout leaps to mind. In a more butterscotch way. Diacetyl can also be more butter than butterscotch. Think artificial popcorn butter flavor.

 

I know I've been utterly annihilated by Fuller's ESB diacetyl taste before. But others have not experienced the same thing - so am I crazy, or is it the world around me?

 

Okay I have one of those in the beer cave I think! Thanks.

 

I will try and pick one of those up and see what I can detect. Thanks!

 

Pilsner Urquell is known to have some Diacetyl.

Samuel Smiths beers have it in high enough levels that i have no problem picking it up.

I have been dinged in comps for Diacetyl In German Pilsners done with 830, big pitch, cold pitch lots of O2. It was low enough I didn't detect it, a friend with a BJCP National rating got a little.

 

Generally 10 degrees above fermentation temp or 65-68F is a good general range (room temp. basically). Usually for a day or two but it depends on how much diacetyl is left. I recently had a lager that was diacetyl bomb after 48 hrs into d-rest so I left it until I couldn't detect it anymore (5 days total). The point is the d-rest is a general guideline not a specific rule/law, because it's possible a lager won't even need a d-rest and it's possible it needs longer than 48hrs so you just have to taste it. You don't want to crash it when diacetyl is present because it would take a lot longer to clean up.

 

In the past I tasted Diacetyl BIG TIME in Redhook ESB. I couldn’t stand that beer. I think I have read that the amount of Diacetyl in Redhook ESB has been ‘toned down’ over the years but I can’t corroborate that; I have not had a Redhook ESB in a very long time (over 15 years ago?).

I do perceive some diacetyl in Pilsner Urquell; particularly in bottles with some age on them.

Now that I have discussed that I am capable of perceiving diacetyl (even at low levels like in Pilsner Urquell) I will state that I have homebrewed with a number of lager strains (about 10 different strains) and I have never conducted a diacetyl rest and I have never perceived diacetyl in those beers.

The lager strain that I use the most is Wyeast 2124. I will be making a yeast starter of 2124 today to homebrew a Bohemian Pilsner later this week. While Wyeast does indeed ‘warn’ that this yeast strain can produce diacetyl, in the number of batches I have made with this strain (about 30 batches) I have never, ever perceived diacetyl from this strain. I do not do anything purposeful in my homebrewing process to mitigate diacetyl. I ferment at around 50°F until the beer stops producing CO2 (plus 1-2 days), transfer to a secondary and lager cold (less than 40°F) for a period of 6-7 weeks (for an OG of around 1.050 beer).

Cheers!

 

You'd have to have a brick for a tongue to not taste the diacetyl in Pilsner Urquell.

 

“You'd have to have a brick for a tongue to not taste the diacetyl in Pilsner Urquell.”

A significant number of people (something like 30-40%?) cannot perceive diacetyl in beer even at extremely high levels (e.g., Redhook ESB of circa 1990). Does 1/3 of the population have a “brick for a tongue”?

Cheers!

P.S. From http://www.brewingtechniques.com/library/backissues/issue5.6/bickham.html

“A sizable percentage of the population cannot detect compounds such as diacetyl and methyl mercaptan in any concentration.”

 

Where are you getting 30-40% from?

Diacetyl can be detected (by some) at levels well below what's in Pilsner Urquell. My point is that one's ability to taste diacetyl in Pilsner Urquell does not imply the ability to taste it at 'low levels.'

 

It is more like 20-25% that are blind to it, IIRC.

Then there is the guy I know the is extremely sensitive to Diacetyl, but is blind to DMS. He can't tell Rolling Rock from other AALs.