washed yeast sediment to slurry cell count question

Tell me if I'm thinking straight. The Wyeast website says that if a slurry sediments out to between 40-60% solids, you can figure that the slurry will correlate to about 1.2 billion cells per ml.

When I rinse my yeast, I finish with the small mason jars. They hold about 200 ml. So, if I understand the math. One such jar, with sediment up to about the half way point would be roughly 240 billion yeast cells. (I know this assumes they haven't been stored for long.)

A jar, one quarter full of sediment would be about 120 billion cells and so on. They always say do the math, but that is usually where I get messed up.

I have a few questions about this kind of thing too. In fact I just took a picture to start a new thread but i'd like to hop on board this one if that's ok.

For me, it boils down to trying to figure out how much of my washed yeast to use in a starter. I know how to use the pitching calculator but my system breaks down in figuring out how much yeast is 248 billion cells.

I used to just toss slurry from 1 jar but as you can see the amount of yeast in my jars varies:



Similar to the OP i need a hand in figuring out approximately how much yeast is in those jars.

kansasbrew - Your math sounds about right to me.

TacoGuthrie - That slurry is waaay too thin, use less water next time.