Lager Fermentation

im fermenting Jamils pilsner and its coming up on 3 weeks of consistent fermentation. i plan to do a diacetyl rest but do not know when to do it. any suggestions?

If you do it when you're 75% of the way to FG, that would be the best time. So, if you started at 1.060, and expect a FG of 1.015, to do it at 1.026 or less would be fine.

If you're not checking the SG very often (and I don't!), waiting until signs of active fermentation slow a bit may get you very close to that, and would be a good time for the diacetyl rest.

thanks for the reply yoop. this first lager is quite exciting! im gonna wait for airlock activity to slow to about 2-3 bubbles a min. i personally only check the gravity before it goes in the fermenter and before i rack to bottle. its still bubbling away krusen has been there for 3 weeks

Lagers are so much different than ales. I've done about six so far. This latest time, I brewed a Helles Bock that took about a month to finish out (may have been done at 3 weeks but I'm in no rush and don't like to take a ton of gravity samples). I harvested the yeast from that and brewed an a BoPils and then an O'fest about 5 days later. SG on both were similar. The O'fest finished after about two weeks, all at lager ferm temps, and the Pils took another 10 days just to get to 75% attenuation, at which point I bumped up the temp to get it to finish faster. Both got pitched in basically the same manner with the same generation of the same yeast, aerated identically, etc.

I guess I'm learning that it just takes lots of patience.