I brewed an Oktoberfest this past weekend. It’s at about 50* right now, and after a diacetyl rest (if needed), I plan on dropping it down to about 38-40. Can I just set the temp control and be done with it, or do I need to slowly drop the temp 1-2* per day?
I have seen no benefit to lowering the temperature slowly after fermentation has finished. I set it and forget it. It does take about 12 hours or so for the beer to go from 60 to 35 in my system. I get good clean beer doing it this way with good liquid German strains. I have had less luck with Bohemian strains.
I’ve done it both ways with no noticeable difference either way. The yeast have completed the fermentation process and are now only doing some minimal cleanup. This is where one wants the yeast to flocculate and the beer to clear as the lagering stage begins. Let it drop at a reasonable pace.
The Germans recommend dropping the temperature by no more than 2C per day. I go 5F per day. But I don’t know how much of a difference it actually makes.
This section does go into the details of this issue: Fermenting Lagers - German brewing and more
When fermentation is completed at the warmer temperature you can cold crash the beer afterwards.
Kai
It took me 20 min of staring at those graphs before coming to the conclusion that you just wrote in one sentence.