unstressing stressed yeast?

So i have washed and frozen a few strains. I recently brewed a Belgain strong ale and didnt have time to cold crash and steal some yeast to farm out and freeze. Since i pitched the whole starter, and it was High gravity, AND my temp control went crazy and i was around 78 by the end of day 1, Id call the yeast "stressed". After racking to secondary I washed and have some remaining yeast.

What would be the best way to unstress them before freezing? Im thinking about taking a very small amount and putting it on the stir plate and letting it ferment out and cold crash. This will result in mostly "new" yeast and shouldnt be "Stressed" right? Not too worried about mutating I only keep 1-2 generations worth.

There is no way, it is impossible to change genetic mutations and everything else that happens. buy more yeast.

<--Agrees with Breez.

breez7 said:

There is no way, it is impossible to change genetic mutations and everything else that happens. buy more yeast.

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This. Stressed yeast isn't just the strain of yeast you pitched that worked long hours in a hot mine that needs a bit of a rest, it's mutated and been changed on a fundamental level. You can't make it mutate back to the original strain. Any new yeast produced in a starter will have the same mutations.

Got a link to any scientific type stuff on stressed yeast mutations? I know alot of stuff is hyped up with no real proof. Just "common knowledge" that has become law. I understand the stressing of the original strain, but how much does it actually mutate in one fermenting? Like when we worry about mutations when washing yeast, Has anyone actually noticed a difference within a reasonable generation?

Also with it being a Belgian type yeast, you are really worried about mutations throwing esters since thats what you are after in the first place. My mine concern is farming up healthy yeast from a little of washings so i can freeze it. Anyone else tried anything else with stressed washed yeast?

Also, not saying that it didnt adversly mutate, just questioning if anyone has data on whether its a noticealbe amount

The only way you'll know if it's noticeably stressed is if you taste it. Yeast is a living organism and doesn't always behave the same way under the same conditions. If the beer you fermented doesn't taste too hot or solventy, not too much banana or other off-flavors for you, then there's no reason not to save the yeast if it produces a character you find desirable. Odds are that it won't give you the same profile you wanted from the original strain and it'll keep getting more pronounced as you move through generations.

You're not just after "esters" because if you were you could ferment an English or American strain hot, or capture a wild yeast, or go with a hefe yeast. You're after a very specific subset of fruity and/or spicy esters that Belgian yeast strains have been bred to produce over hundreds if not thousands of generations and are now rebuilt from a single cell to ensure uniformity of flavor production.

Farming it out and freezing is cheap and easy, its the $25 in ingredients from the next batch that I dont really want to risk..... ughhh... should have just postponed the brew until i was able to crash and steal some to freeze... I HATE paying $7 for yeast when i have a PINT of it from previous brew

Steal some of your brew in secondary, or if you can't, make a 2L test batch at the proper temps with an airlock and give it a smell/taste when it's finished fermenting. That should give you an idea of the kind of yeast profile you'll be getting.


e: what strain was it? Some are better than others at crazy high temps like you had.

The only data I know of is what Chris White, president of white labs, said in his book 'Yeast'.........

My guess is its pretty accurate. Thats where I got my info.

Did your yeast mutate while fermenting your Belgian? Yes.

Do those mutations make any difference? Probably not.

Should you save this yeast after primary? Up to you, but I would.

theredben said:

Did your yeast mutate while fermenting your Belgian? Yes.

Do those mutations make any difference? Probably not.

Should you save this yeast after primary? Up to you, but I would.

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Thats my thinking also. Im sure I didnt do the yeast any favors, but I doubt its going to make much of a taste difference. It was WLP570. I planned on ramping to 80, just not within the first day lol.

You think its even needed to grow out some fresh yeast from a little of what i washed or ok to just freeze the washed yeast? "Stressed" is such a nebulous term.

No need to grow any extra generations, if it is good to go out of the primary, then it's good for the freezer.