Author Topic: Diacetyl rest for ales  (Read 3823 times)

Offline flbrewer

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Diacetyl rest for ales
« on: December 29, 2015, 02:44:19 PM »
Is this ever a necessity? Does anyone do it?

Offline Stevie

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Re: Diacetyl rest for ales
« Reply #1 on: December 29, 2015, 02:51:41 PM »
I raise the temp on ales that I ferment at lower temps, but that is more to keep it from stalling than fear of diacetyl.

Offline Frankenbrew

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Re: Diacetyl rest for ales
« Reply #2 on: December 29, 2015, 02:53:14 PM »
I've never done it, and I've been brewing ales for 21 years. If you are fermenting in the mid 60s, just leave it on the yeast cake for a few days after fermentation is done, and you will be good to go. I almost never rack off the yeast sooner than three weeks, and I've never had a problem with off-flavors.
Frank C.

And thereof comes the proverb: 'Blessing of your
heart, you brew good ale.'

Offline HoosierBrew

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Re: Diacetyl rest for ales
« Reply #3 on: December 29, 2015, 03:02:33 PM »
I raise the temp on ales that I ferment at lower temps, but that is more to keep it from stalling than fear of diacetyl.


+1. Between raising temp at the end and often waiting 3 or 4 weeks to keg (busy work/family schedule), the yeast has more than enough to clean up after itself.
Jon H.

Offline tommymorris

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Re: Diacetyl rest for ales
« Reply #4 on: December 29, 2015, 03:05:49 PM »
I have noticed wlp002 puts off lots of diacetyl and then does a really good job cleaning it up later. When I take a gravity reading right after krausen drop I usually regret it because the sample tastes like butter. One week later that butter flavor has always been gone.  I suspect packaging wlp002 beer too early would be a bad idea.

Offline HoosierBrew

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Re: Diacetyl rest for ales
« Reply #5 on: December 29, 2015, 03:19:44 PM »
I suspect packaging wlp002 beer too early would be a bad idea.

For sure, I've noticed that, too. And the Irish 1084 strain has a ton early on, and never fully dissipates IME. I'm a big believer in 3 weeks in primary (4 weeks for big beers). Exceptions being hefeweizen or wit which get kegged quickly.
Jon H.

Offline flbrewer

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Re: Diacetyl rest for ales
« Reply #6 on: December 29, 2015, 03:37:19 PM »
This recipe actually calls for a lowering of temp to 60F.

Offline klickitat jim

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Re: Diacetyl rest for ales
« Reply #7 on: December 29, 2015, 03:45:39 PM »
This recipe actually calls for a lowering of temp to 60F.
Lower it to 60 when?

I only lower temps if fermentation is completed including uptake of Diacetyl. Lowering temp is used to speed up putting yeast into dormancy and to drop them out of suspension

Offline flbrewer

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Re: Diacetyl rest for ales
« Reply #8 on: December 29, 2015, 07:28:41 PM »
This came from a 2015 AHA presentation on Hop-fu...I've listed the brewing process below which mentions the rest.

Day 1: Cool wort to ideal pitching temp of 67F, Aerate wort with pure O2 through diffusion stone, Pitch yeast starter or freshly harvested slurry, and Attach blow off tubing
Day 2-7: Maintain 67F fermentation temperature via external temp controller
Day 8: Remove blow off, seal fermenter (keg or conical only!!)
Day 10: Reduce to 60F for diacetyl rest
Day 11: Dump trub, harvest yeast slurry, add dry hops, return to 67F Day 14-16: Begin crash cycle, cooling 10F every 12 hours until 37F Day 17: Rack...

Offline klickitat jim

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Re: Diacetyl rest for ales
« Reply #9 on: December 29, 2015, 07:55:09 PM »
This came from a 2015 AHA presentation on Hop-fu...I've listed the brewing process below which mentions the rest.

Day 1: Cool wort to ideal pitching temp of 67F, Aerate wort with pure O2 through diffusion stone, Pitch yeast starter or freshly harvested slurry, and Attach blow off tubing
Day 2-7: Maintain 67F fermentation temperature via external temp controller
Day 8: Remove blow off, seal fermenter (keg or conical only!!)
Day 10: Reduce to 60F for diacetyl rest
Day 11: Dump trub, harvest yeast slurry, add dry hops, return to 67F Day 14-16: Begin crash cycle, cooling 10F every 12 hours until 37F Day 17: Rack...
Has to be typo.  I could see "raise to 70" but then I would not drop the temp again until it was time to crash.

Offline brewinhard

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Re: Diacetyl rest for ales
« Reply #10 on: December 29, 2015, 08:19:42 PM »
This came from a 2015 AHA presentation on Hop-fu...I've listed the brewing process below which mentions the rest.

Day 1: Cool wort to ideal pitching temp of 67F, Aerate wort with pure O2 through diffusion stone, Pitch yeast starter or freshly harvested slurry, and Attach blow off tubing
Day 2-7: Maintain 67F fermentation temperature via external temp controller
Day 8: Remove blow off, seal fermenter (keg or conical only!!)
Day 10: Reduce to 60F for diacetyl rest
Day 11: Dump trub, harvest yeast slurry, add dry hops, return to 67F Day 14-16: Begin crash cycle, cooling 10F every 12 hours until 37F Day 17: Rack...
Has to be typo.  I could see "raise to 70" but then I would not drop the temp again until it was time to crash.

Unless primary fermentation has completed along with an acceptable terminal gravity and one desires to dry hops at a cooler temp (say around 60F). But I think it is better practice to allow the beer to rise in temps slowly towards the end of fermentation to allow for proper conditioning and attenuation.