Lagering temps

[buckeyebrewer]

I made a 10 gallon batch of Sam Adams Noble Pilsner. I am lagering two 5 gallon carboys in a fridge. They have been 50-52 degrees for a week and fermenting well. Today (8th day of activity) I set the temp controller to 60 degrees for a diacetyl rest. Its still fermenting....I can see activity in the airlock every 5 seconds or so. I guess my question is.... at what percent is it safe to increase the temp and finish the ferment. 75% ...90...100? Do you let your beer finish fermenting and then give it the diacetyl rest. Thanks

 

[Yooper]

I raise the temperature to a diacetyl rest temp when I'm 75% of the way to FG. Since you're already at the diacetyl rest temp, there you are. I wouldn't do anything now until you're at FG. Airlock bubbling really doesn't mean a thing, so SG readings are the only guide. Warmer temperatures will make the airlock bubble, regardless of the fermentation level. Anyway, since you're at the diacetyl rest temps now, you don't want to do anything else until the diacetyl rest is over.

After you're at FG and there is NO taste of diacetyl to the beer, then you can rack and begin the lagering phase.