How long in primary

Was wondering how long you can keep a brew sitting on yeast in the primary before worrying about autolysis?

Weeks at least and some of us have gone months.

Temperature is going to come into play as well, lower temps will help hold off autolysis longer.  The ROT I hear thrown around is 4 weeks is fine at ale temps, longer if you’re fermenting at lager temps.

But it can and does happen.

Having learned through experimentation (code for the hard-way) it’s better to get the brew off the yeast sooner than later.

Reason why i’m asking is I have a nut brown fermenting in the primary now for about close to two months and I want to use that yeast to ferment another beer.  I tried a sample of the nut brown and it smells and tastes pretty good so i’m figuring the yeast will be fine for the next brew which is an old ale high gravity.

I personally would not use a yeast that old unless I made a starter out of it first.

Hey Tom
I would definitely figure out how old the yeast is. If it is just over a month I would try it but if it is 2 months I would think that you would have little chance of a good fermentation going on.