How can I remove dead yeast from a starter?

[Skyforger]

I'm brewing a gingerbread brown ale right now. Made a 1L starter (just making a 2.5gal batch) from a yeast slurry I've been storing about 2 months in the fridge. Thing is, I used too much of the original slurry, and now I have a nice, healthy yeast layer growing on top of a dark layer of (I assume) dead yeast. I'd rather not pitch the dead yeast in if I can help it, as I'm not planning on using a secondary for this batch. It will probably be on the yeast cake 2-3 weeks, and I don't want problems with autolysis.

Any ideas on how I can separate the living and the dead yeast? I realize I should have made a mini-starter, and then used that to make the full size, but hindsight's 20/20.

 

[Clubbinaz]

Yea, I don't like throwing the "dead" yeast either but fact is, they just sink to the bottom sediment and get covered by their millions of dead brothers anyways as you ferment. I have never personally run into a real problem with yeast but then again, I open the bottom port on my conical and drain the sediment pretty regularly..

PS: That sounds like a great project. If you like the end result, send me the recipe, I would like a nice holiday brew project.

 

[Skyforger]

Yeah, I suspect it won't be a problem, but I'd like to get them out if possible. If not, oh well. I just want this to have a pretty clean taste, the malts and spices alone. Trying to eliminate potential problems.

Any ideas are welcome.

And I'll definitely post the recipe if it turns out; I'm pretty enthusiastic about it, the wort smells great.

 

[Randar]

dark layer in the starter is usually trub and break material, not "dead yeast".

1) There is no way to tell the dead yeast from the live yeast as you are supposing you can do.
2) Because sedimentation and/or flocculation of yeast has occured does not mean that the yeast are no longer active or able to quickly resume metabolic and reproductive active. This is why stir plates are most effective. They force the yeast into suspension and assure the cells are exposed to nutrients and consummables until the wort if "spent" (as opposed to forming a thick sediment layer and allowing only a portion of the yeast access to the nutrients/sugars).
3) RDWHAHB and pitch it all (decant the spent wort if you'd like)

 

[Skyforger]

Alright, thanks. I'll just pitch it all.

 

[yodalegomaster]

The real question is why would you want to do this? Dead yeast (Called Biotin) is what they make yeast energizer out of.

 

[kanzimonson]

FYI, biotin is a vitamin. But I also don't think that's the right logic there - if pitching dead yeast in your beer were a good thing, then nobody would complain about autolysis, ever. Usually when I've seen people talk about putting yeast that they've cultured into their beers for nutrients, they're usually added to the boil. I don't really know enough about the science to give definitive info here, but it seems like boiling the yeast is essential if you want to use them for nutrients.

 

[rocketman768]

1) There is no way to tell the dead yeast from the live yeast as you are supposing you can do.

Actually, yeast tend to turn gray as they use up their glycogen reserves, so he could be seeing dead yeast. Still, the only way I can think of to separate one from the other is by centrifuge if you had one, or by just doing another starter, but these are both probably overkill unless you have some reason to fear autolysis.