Washing "stressed yeast"

[Tinpanharry]

So if I underpitch and stress the yeast, or ferment at too high a temp, producing a poor tasting beer, should I harvest and reuse the yeast in this cake, or throw it out?

In other words, is the yeast still good?

Cheers,
TPH

 

[giraffe]

Too high a temp, would effect the beer, but not really yeast health, Id repitch that yeast without issue.

High alcohol beers, or other stresses that would effect yeast health/viability, id be more prone to dump and get a fresh culture for safety. Though if its a strain thats not available, you can make a starter from the harvested yeast, and check viability first, it is usually fine.

 

[DurtyChemist]

I'd say it is still good. Plenty if people will tell you it isn't worth keeping yeast that were stressed or didn't live in optimal conditions. I would wash it and keep some until you taste the beer. If it tastes like bad off flavors from yeast I'd toss the yeast.

 

[krackin]

I de-stress all my yeast by playing Stones, CCR, Beck or Bing Crosby.

 

[Leithoa]

Are you willing to wager a brew session's worth of ingredients and time on a yeast that may give you bad beer?

Unless it was some hard to get strain or you just wanted to practice your methods I wouldn't make the effort to save the yeast cake, but that's my attitude towards most yeast cakes (prefer to save yeast from my starters).

Without a yeast lab and some experience with the techniques the only way to tell how much, or if, the yeast have changed is to brew beer. Make a starter and split it then throw some DME and hops in a gallon of water and boil up a quick batch. If it tastes good, keep on rockin' in the free world.

To expand on giraffe's comment:
Yeast will be happy into the upper 70's and some times low 80's (strain dependent). Above that viability goes down but overall isn't horrible for anything but the beer you wanted to drink. Yeast propagation

 

[eadavis80]

I'd say if you know the yeast did a bad job, it's not worth trying to save $7 in yeast while risking $35 in ingredients. I have only used washed yeast in batches where I was confident the yeast did a nice job. So far, so good...

 

[Brew_G]

I'm no expert, but wouldn't pitching at a higher temp actually result in a less stressed yeast?

 

[Leithoa]

To a point. The downside is at higher temperatures they produce more esters that negatively affect flavor and aroma. Once you get into the mid-upper 80's and 90's the temperature affects the yeast health.