[Washing] are Porter/Stout yeasts darker color?

[olie]

I've begun experimenting with yeast harvesting & washing. My pales separate nicely and leave a nice, white, creamy yeast. However, three separate collections of yeast from porter & stouts have resulted in what appears to me to be a much browner yeast layer.

I think.

...Or do I just need to keep washing because it's still got "stuff" in it?

Is the clean yeast-cake from my porters & stouts expected to be the same creamy color, or might it be like a dark-sand beach vs a white-sand beach?

Thanks!
~Ted

 

[kh54s10]

It is the color coming from the beer. Don't bother trying to wash the yeast at all. Just swirl up the cake after siphoning off the beer. Pour the cake into sanitized mason jars and store in the fridge. Use a quarter to a third in the next batch. The yeast stay healthier under a layer of beer than they do under water.

The beer remaining in the yeast cake will add some flavor to the new batch so it is best to save from low gravity pale beers. High gravity beers will leave you with stressed yeast.

If your porter or stout was not too high gravity the yeast should be OK and good for use in another dark beer. I would not use it in a pale beer. You will get some flavors from the yeast and maybe a bit of color added. Even if you try to wash the yeast.

 

[Jtvann]

I've always heard the same thing. High gravity beers lead to stressed yeast. Why is that? Not arguing, just curious. If an appropriate yeast pitch is used, that falls well within the yeasts alcohol tolerance level, that had good temp control, why would it be stressed?

I'm about to make a 1.085 OG beer in a few weeks. Using San Diego Super yeast. I'm considering harvesting and reusing that yeast in identical beers. I'd really only use it for similar type beers.

 

[olie]

I've always heard the same thing. High gravity beers lead to stressed yeast. Why is that?

I'm totally just guessing here, but perhaps not so much the OG, but the ABV at the end, that leaves the yeast not in its healthiest state. To paraphrase a couple of experts:

Cliffy: "Alcohol kills yeast cells."
Norm: "Yeah, but only the weak ones."

I'd love to learn more about this. One of the challenges of brewing is that there's a lot of superstition and ju-ju, but also a lot of it is based in fact, some number of iterations ago. It's just been handed down and "improved" so many times that it can sometimes be difficult to sort out the science from the "because my grandfather said so".

I'm considering harvesting and reusing that yeast in identical beers. I'd really only use it for similar type beers.

Do the science. I am, too. If I learn something useful, I'll report-in here. Of course, with the sample sizes I'm likely to use (a couple of batches), it'll be mostly superstition by the time I form an opinion, but that's kind-a how science starts off, right?

 

[InspectorJon]

I've always heard the same thing. High gravity beers lead to stressed yeast. Why is that? Not arguing, just curious. If an appropriate yeast pitch is used, that falls well within the yeasts alcohol tolerance level, that had good temp control, why would it be stressed?

I got a pretty good answer to this question here:
https://www.homebrewtalk.com/forum/threads/harvesting-yeast.664666/#post-8573304

 

[InspectorJon]

@Jtvann The answer about yeast from high gravity beer is in post 26 in the thread referenced above.