when do you like to do a diacetyl rest?

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when do you do your diacetyl rest

  • 7 to 10 days

    Votes: 2 13.3%
  • at a rough or specific attenuation ( ex 70 to 90 percent, or at x percent)

    Votes: 5 33.3%
  • when i see the activity slow or stop

    Votes: 6 40.0%
  • whats a diacetyl rest? ( no rest)

    Votes: 2 13.3%

  • Total voters


Well-Known Member
Dec 1, 2008
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i used to do a DAR at day 10 but since i got my wifi hydrometer im thinking i can hone it into around 75 percent attenuation both of which i have seen reccomended. when do you brewers like to do your rest if you do one. thanks for any responces.
1) Take your OG reading
2) Look at the digits to the right of the decimal (e.g., 1.056 --> 56)
3) Divide by 2 (e.g., 56 / 2 = 28)
4) Put a 1.0 in the front and start the D rest there IF needed or desired (e.g., 1.028)
5) IF you actually detect diacetyl in the aroma or flavor, let it rest longer than the typically recommended X days. Give it at least a couple of WEEKS before chilling, that's how long it actually takes a lot of the time -- don't cold crash, leave it warm until that diacetyl is gone.
6) Package and condition as normal
I'm same as OP. I was doing 7 to 10 days but just finished my second batch with the iSpindel and will be going for 75% now.
When fermentation activity has slowed, I do a trub dump and take gravity measurement. When (very) approximately 90% attenuated I rack to kegs and put heat wrap on them if cellar temp dictates. Ramp up and D rest at same time as spund carbonation is taking place. This makes sense, since both D rest and spunding rely on the yeast being still active.

I agree with dmtaylor that d rest can take longer than many people give it. I used to follow advice like; "ramp up to 64F rest 3-5 days, ramp down and crash. But since I started spunding after kegging, and therefore taking pressure readings on kegs, I have come to realize the yeast can take a couple of weeks to fully clean up beer and stop working, even at controlled temp of around 65F.
I started waiting until activity slows down. For some reason I get different attenuation rates. My last two tests used 1pack of S-189 split between the two. Both were (according to BrewFather) expected to finish ~1.013 and 1.014 but finished 1.014 and 1.018 respectively.
I keep an eye on my Tilt and ramp up when I'm a few points away from finish.
A typical fermentation/temp plot from my Tilt looks something like this: