Yeast harvesting/washing question

[sdbyrd]

I'm washing my yeast for the first time and trying to figure out if I'm on the path to success or not. I have a Belgian Quad that I racked into the secondary and started washing the yeast for round one. I then put the remaining jars in the fridge overnight and woke up to the following picture. At this point, I'm trying to figure out if the bottom layer is more trub or is it yeast? It's making it more difficult because most pictures I see of the separation are with lighter beers, whereas mine is pretty dark. Also, might be hard to tell in the photo, but light does shine through the top 1/4 of the liquid on top, then it gets really dark in the middle. Any suggestions would be greatly appreciated!

 

[brewshki]

It looks like a lot of yeast. The one time I did it, I got a much better view of the trub by holding the jar up and looking at the bottom.

 

[IslandLizard]

That looks really clean! How much did you "wash" it? What's on top of the yeast, beer + water mix? It's still quite dark.

You can let it crash a few more days until the beer on top becomes clear, thus harvesting all the suspended yeast. Before re-using, make a new starter from the slurries after decanting the beer off the top.

 

[sdbyrd]

It only went through one round of washing (started with lots of jars) and let it sit for a few hours at room temperature. Then, I transferred into the jars you see in the picture and put them in the fridge overnight. If I'm doing it right so far, I was expecting to have more of the milky layer yeast, considering the yeast cake was originally 2 liquid vials + starter.

 

[IslandLizard]

If you let it sit for too long during the "wash," the washing liquid will lose the higher flocculant yeast population, which settles on top of the trub as well as being mixed in. Did you recover some of that layer too?

Most of us don't wash yeast anymore, or not thoroughly at least, simply pitch trubby yeast mix.

Yeast keeps best with beer on top, not water. That's why I asked how much beer is still in that liquid.

That said, after fermenting high gravity beers, it's good practice to reduce the alcohol percentage of the beer the yeast will be stored on to around 5-6% to prevent early autolysis. Simply diluting with sterile water will accomplish that.

This yeast has gone through a lot of abuse by the high gravity fermentation, and may or may not be suitable for another batch. I'm on the side to say "what doesn't kill you makes you stronger," is valid for yeast too, so maybe a pitch of half the harvested slurry and half cultured (through a starter) from a fresh pack (or ranched from a starter) may give you best of both worlds. Always make a fresh starter after a month (or 2) of storage.