we brewed a Russian Imperial Stout on Friday.
Fermentation started on Saturday, it stopped last night.
The yeast we used was a Sarfale S-04 with a temperature range from 64-75 degrees.
The ambient temperature of the basement is 60, along with the fementer temp.
Is it possible that the yeast has gone to sleep?
Can we bring the temp back up to restart fermentation or is it over?
Did you check the current gravity?
No, just found this news out. We’ll do that, and check the ABV
If you are basing the conclusion that fermentation stopped on just visual information i.e. there is no longer krausen then chances are its still fermenting. The krausen typically falls away after a few days but it is still fermenting.
Take a gravity reading with sanitized equipment today then again in 2 days. If the gravity is lower the second time its definitly still fermenting.
If there has been no big temperature swings where the fermenter is I would actually wait another week before testing because I doubt very much that fermentation stopped.
It is not unusual for S-04 to complete fermentation in four days. http://www.fermentis.com/wp-content/uploads/2016/12/SafAle-S-043.pdf
Not sure what the gravity is here but its a RIS so maybe a little longer.
OP: even if terminal gravity is reached its good to leave in the fermenter for a couple weeks before bottling as even though fermentation may be complete the yeast still “cleans up” off flavors produced during fermentation.
The wort entered fermenter at 79 degrees with an OG of 1.070.
With the lowered temp we think fermentation has slowed but is still active.
There’s no way we’re going to bottle without a definite assurance that fermentation is complete.
Is a gravity check the best way to know?
I was given the advice to let it sit in the primary fermenter for 3 weeks, to let everything settle.
Good advice?
A gravity check is the only way to know if fermentation has finished.
If you decide to leave the beer in the fermenter for 3 weeks, it will be absolutely fine.
Holy crap…if you pitched at 79F it likely finished fermentation in just a few days. Do a gravity check.