Go ahead and do a diacetyl rest? Bohemian Pilsner

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Well-Known Member
Mar 25, 2015
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I'm on Day 5 of lagering 11 gallons of a 1.045 OG Pilsner (my first lager).

I did a split batch and had WY2124 (recommended yeast temp range of 45°-55°) in one carboy and WLP833 (recommended yeast temp range of 48°-55°) in another. Right now they are both sitting at 50° in the same fermentation chamber. Plan was to have them at 50° for a week, then 55° for 2-3 days, then a D-Rest for 3 days around day 10...

I've read you should do a D-rest around 80% attenuation. Well right now I have
WY2124 @ 82% AA (1.016)
WLP833 @ 67% AA (1.020).

Should I go ahead and ramp the temp to 65° to do the D-Rest or allow WLP833 to hit 80% (1.018) before I raise the temp? My only concern is that WY2124 may actually finish before WLP833 ever gets to 80% over the next couple days.

Or maybe kick the temp to 55° now and hold for 1 day, then hit 65° over the weekend for the D-rest?


Lord Idiot the Lazy
HBT Supporter
Nov 8, 2009
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Two Rivers, WI
If doing a D rest, I aim for when gravity units are half of what you started with. So for your 1.045 pilsners, I would have commenced D rest at 1.022 (45/2 = 22.5).

So, do it now, if you're going to do it. Don't wait any longer.

On the other hand, if the beers don't smell or taste like buttered popcorn or butterscotch, it's also safe to skip the D rest completely. Sample them and find out.

But if you need to do the D rest, do it now. And if you're not sure, do it now. It won't hurt anything. Sometimes I do the rest without sampling, because it hurts nothing.


Well-Known Member
Dec 6, 2014
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I do them with 5 gravity points remaining from the estimated FG. If you wait for the second batch to finish the first will be completed and you have only a bit of yeast in suspension to finish the first batch.

I think you’ll be fine to bump your temp up now. I doubt you’ll experience any off flavors from the temp rise on the less attenuated batch at this point. It’ll just speed up yeast activity a bit.