Diacetyl Rest

[Butkus]

Brewed my first lager over the weekend, and I wanted some "daily affirmation" about what I'm doing.

Background info:

1. I brewed a Pils with an 1.055 OG.
2. I cooled it down to 49 degrees F before pitching
3. Using WL Czech Pils yeast, and I made a 1 gallon starter
4. It is currently fermenting away at 50 degrees F.

I plan to just keep it in the primary fermenter for 3 or 4 weeks and then rack to a keg for lagering.

Should I be okay without a Diacetyl rest?
When I rack after 4 weeks, if the sample tastes buttery, is it too late to do a diacetyl rest at that point?

[J.Brew]

Is there a particular reason that you don't wish to incorporate a diacetyl rest? I know that not everyone does and I believe I've heard Jamil denounce the importance of the rest when a healthy and adequate amount of yeast is pitched though I could be wrong. Lager discussions always intrigue me as I have little experience with brewing them.

[Butkus]

I have no vested interest in doing or not doing a rest. I just don't want to do something for the sake of doing it, and it seems like it would be better to see if I had a diacetyl problem in the sample before giving it a rest to fix it.

But, it does seem like a pain to warm it up from 50 to 65 degrees for 48 hours just before crashing it back down to lagering temperatures. Yeah, that's it; I'm trying to save energy, what with global warming and all . . .

[BDawg]

Everywhere I've read, the time to do the diacetyl rest is when the beer has gotten down to 66%-75% of its target attenuation. Taste it at that point. If it tastes "like butta", then do the diacetyl rest. If not, don't.

So, if your OG is 1.048 and your target is 1.012 (75% AA or 36 pts):

48 - (.66 * 36) = ~24 => 1.024
48 - (.75 * 36) = 21 => 1.021

When it gets to between 1.021 and 1.024, give it the old taste test. There will be plenty of yeast left at that time. I wouldn't wait until it flocs out to taste it.

HTH-