Salvage yeast from a hot fermentation?

[Guitarded97]

Hi all,

I brewed a Belgian Dubbel, with the intention of using it as a giant starter for a Belgian Quad. My plan was to rack the Quad onto the Dubbel's yeast cake and use the same yeast.

The problem is..... My temperature control went out on me and the Dubbel got REAL hot, like almost 90 degrees hot. As soon as I saw it, I gave it an ice bath and got it down to the mid-60s, where it was supposed to be. Activity has mellowed out since then. Just tried it and doesn't taste great. Lots of fussel alcohols, as expected.

So, my question is.... Given that the whole purpose of brewing the Dubbel, was to be a big starter for the Quad, can I still use the yeast and just be more mindful of the fermentation temp this go around? Or are the yeast "ruined"?

 

[Professor Frink]

That temp shouldn’t significantly harm the yeast, especially if you cooled it quickly. Hot, but not hot enough to kill them. Let it ride.

 

[day_trippr]

Well...otoh, I must state the conventional wisdom is to not re-use obviously stressed yeast to take on an even bigger task...

Cheers! (good grief, an exBeeriment looking to happen! )

 

[Ralphie0523]

Obviously the hot fermentation produced undesirable results. But from a chemical and biological reaction standpoint, the yeast simply responded to their environment and to a certain extent when you ferment and repitch you select yeast more optimal for that environment.

A better environment will give the yeast more reason to select the desirable pathways to ferment with no reason to activate the other pathways. Genetic selection in fermentation is a thing but I think somewhat overstated generation to generation unless you have a very good idea of what you are doing and selecting for.

I wouldn’t worry about it too much, if you had done this over a few batches you would probably have way more to worry about. Give yeast the right environment and they will do what you ask of them. I would definitely pay attention to the yeast health and have a very nice size pitch for the Quad.