When to do diacetyl rest?

Sat Sep 06, 2008 6:17 am

I just brewed my first lager 12 days ago. It started slow, but has since been fermenting steadily for eight or so days. I plan on raising the temp 5-8 deg (from 50 deg) to do a diacetyl rest and wondered when I should do this :?: I'm getting a bubble from the carboy about every 10-12 seconds. Do I wait until just before I transfer it to my lagering vessel (corny) :?:

Cheers,
Mike
Sour/Brett Beer Fermenting: Lambic, Kreik, Flanders Red, Berliner Weisse, Orval, English Stock Ale
On Tap: nothing
Next on Tap: Belgian Pale Ale, American ESB and Sweet Cider
Next to Brew: Belgian Tripel and Dark Strong Ale
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MikeB
 
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Re: When to do diacetyl rest?

Sat Sep 06, 2008 8:10 am

Now is a good time to raise the temp, but go higher, 65-68F. Click HERE for more information on diacetyl.
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BrewTa2
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Re: When to do diacetyl rest?

Sat Sep 06, 2008 4:18 pm

+1, what he said.

The unofficial rule of thumb is to do the diacetyl rest when fermentation is about 2/3 done. So, if you have a beer at an OG of 1.050 that you expect to finish at 1.013, you'd want to do the diacetyl rest when the gravity reaches (50-13)/3 + 13 = 25 gravity points = 1.025. Make sense? Otherwise, if you don't want to dick around with math or taking gravity readings (I don't always), just give it about 8-10 days fermentation, then raise it up to about 60 F for about 3 days, by then your fermentation might be done, or if not, you can bring 'er back down to the 50s again to finish up before lagering. It may look like rocket science but it really doesn't need to be. You can wing it and it'll turn out fine.
Dave

"This is grain, which any fool can eat, but for which the Lord intended a more divine means of consumption. Let us give praise to our Maker, and glory to His bounty, by learning about... BEER!" - Friar Tuck (Robin Hood - Prince of Thieves)
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dmtaylor
 
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Re: When to do diacetyl rest?

Sun Sep 07, 2008 6:29 am

Thanks for the info. I thought you'd want to have a fairly active fermentation while doing the rest. It's at 60 and climbing.
Sour/Brett Beer Fermenting: Lambic, Kreik, Flanders Red, Berliner Weisse, Orval, English Stock Ale
On Tap: nothing
Next on Tap: Belgian Pale Ale, American ESB and Sweet Cider
Next to Brew: Belgian Tripel and Dark Strong Ale
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MikeB
 
Posts: 181
Joined: Thu Sep 04, 2008 2:00 pm
Location: Grantham, NH

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