How much of this is yeast...

[Kanonen80]

I'm gonna be that guy and ask you guys how much of this you think is yeast. I am usually pretty good at telling but this one has me a bit confused.

WLP0013 London Ale - after a brew I decanted as much yeast slurry off of the trub as I could. Had it in my fridge for a few weeks, but it was going to be a couple more weeks until I was going to be ready to use it. I made a 2L starter, crashed after fermentation was pretty much through, decanted, stored in a mason jar.

I'm seeing three layers here: kind of a cottage cheesy bottom later, the large brown middle, the thin white top.

Is the large brown middle a mix of yeast and trub, or did I somehow throw the baby out with the bath water when I decanted? If it is a mix, how would I figure the density/cell count of the white and brown layers?

Thanks!

 

[brewbama]

I dunno. Make a starter and see how it goes. Trub doesn’t propagate.

 

[Kanonen80]

I dunno. Make a starter and see how it goes. Trub doesn’t propagate.

Yeah, wasn't sure if it was left over from the initial brew I recovered the yeast from or not. But definitely wasn't that much left over in the initial mason jar, so must be yeast, right? Right?

 

[Robert65]

All looks like yeast to me. You'll get different layers as even in one pitch some cells flocculate differently, and different colors since newly grown yeast is whiter than the yeast carried over from the previous pitch. Brewbama's right, trub doesn't propagate. But I'd say that means you can toss it all in the next batch without worrying about trub, too, if you want to save the trouble of a starter. I always collect a set amount of slurry and repitch it all without separating the small amount of trub. If you ever think there's more trub than usual, just pitch more of the slurry to compensate. The less you mess with the yeast the better.

 

[Tobor_8thMan]

If settled for enough time the white layer between the trub and liquid.

 

[yowzers]

I'd just make it easy and use all of it.

 

[Kickass]

I’m with @Robert65. All yeast. Dump the whole lot into the next brew