Yeast Washing And Temperature

[peas_and_corn]

I am planning to get the yeast cake from my current run of beers, wash the yeast and store the yeast. If I take the cake, put it in a sanitised jar, and then put it into a fridge (so the yeast/trub/other crap will settle and separate out), will the yeast suffer from thermal shock, since the cake will drop from 19C to 3C in a reasonably short time? Or is thermal shock only an issue with suddenly raised temperatures? What sort of effect will this have on yeast viability?

Cheers,
Dave

 

[raven19]

Seeing as you are going to be chilling the sample to get the yeast to fall out of solution, and then store the yeast, I dont think shocking the yeast will be an issue - my understanding is the yeasties will just fall asleep till you wake them up when its time to repitch!

I have had more issues with older slants getting going again compared to stored yeast in terms of viability. I always test with a starter too nowadays just incase.

 

[peas_and_corn]

Well, starters are always the right way to go with yeast

 

[BobtheBrewer]

I am planning to get the yeast cake from my current run of beers, wash the yeast and store the yeast. If I take the cake, put it in a sanitised jar, and then put it into a fridge (so the yeast/trub/other crap will settle and separate out), will the yeast suffer from thermal shock, since the cake will drop from 19C to 3C in a reasonably short time? Or is thermal shock only an issue with suddenly raised temperatures? What sort of effect will this have on yeast viability?

Cheers,
Dave

I've found that keeping the harvested yeast (in a PET bottle) in the fridge and every few days when it has settled tipping out the beer? on top, filling up again with cold boiled water, shaking and then going back to step one works pretty well.