Another first time harvesting... "What part is the yeast?" question

[bucketnative]

This is my first time harvesting/washing yeast from a witbier that I bottled last week. I have "harvested" yeast from the fermenter before, but that entailed just skimming some sediment and depositing it in a cider fermenter. It worked, and I got cider, but for beer, I want to go through the washing process and eventually build a starter out of this.

The yeast was Safale K-97. Upon emptying the 3-gal fermenter, I swirled some boiled/cooled water around over the cake. I did it gently enough that I left behind quite a bit of the trub, what I skimmed off with a sanitized ladle was thin and milky, with large clumps left adhering to the bottom of the fermenter.

I let them settle for a few days in sanitized Mason jars and it looks like the attached photos. In all the tutorials, there is usually a clear dividing line between sedimentary trub and milky looking yeast. With this, the sediment is "flowy", not compacted. At the very bottom, I can see some trub-like sediment. Is it all yeast?

I was planning on an additional wash this evening. Advice?

 

[eadavis80]

It looks like good clean yeast to me. You probably don't 'need' a starter with that amount, but like a blowoff tube - you won't regret making one. It will serve as concrete evidence that what you harvested/washed is viable yeast. I always make starters for liquid and harvested yeast for this reason. I'd rather overpitch that pitch stuff that wasn't viable.

 

[bucketnative]

It looks like good clean yeast to me. You probably don't 'need' a starter with that amount.

For reference, those are the 8 oz jelly-sized Mason jars.

 

[TurnipGreen]

That looks fantastic! All of that is yeast. If you read the sticky on simple yeast saving there is an article in there that actually says in the trub there is a surprising amount of yeast and even floating around the beer on top (water in your case) there is a ton of yeast.

I do the super simple process and just dump it all into a jar, decant a bit and pitch it when I need it. But yours looks great. Surely you won't see any influence of your last brew in your next one.

 

[bucketnative]

That looks fantastic! All of that is yeast... Surely you won't see any influence of your last brew in your next one.

Well that's good news. I really liked the K-97 in a witbier in the hydrometer sample at bottling time. I'll happily be using this on the next batch.

 

[kh54s10]

I agree, most of the white stuff is yeast. Where will be lighter trub mixed in, the heavier trub is what you see on the bottom.

http://www.mrmalty.com/calc/calc.html

On this site there is a calculator for using yeast slurry. You have to estimate the density of the trub and use age to estimate viability. It will tell you the amount to use. Depending on the age of the harvested yeast, you can use it as is, or with older yeast calculate what would be needed to make a starter.