Two tone yeast cake

Yet another question on re-using yeast. I decided to try freezing a few test tubes of yeast, but from a starter instead of a 5 gal batch, thinking it wouldn't require washing. I made a starter, let it go until it seemed done, let it settle, poured off most of the liquid, added some more wort (wanted to make sure I had a health cell count), let it go a few more days, settle, pour off liquid, agitate, pour into test tubes, let settle. Now what I have looks like this:



The same separation was apparent in the flask before I agitated it. Is it beer->yeast->trub? The stuff at the bottom seems to be considerable heavier. Was I wrong in thinking that the starter wouldn't produce much trub because of the small quantity and not require washing? From looking at other people pictures detailing the yeast washing process, mine does not look the same, the bottom layer is much lighter. Can anyone shed some light for me?

Todd

I think it's beer, and yeast...the middle layer is probably an unsettled mix. Over time, it should settle out and you'll see two layers...yeast and liquid.

If it were trub, it would be on the bottom, and likely darker than the yeast.

I've had some yeasts do that also. I just assumed that it went bad and tossed them as my other washings aren't like that.