Yeast washing...which bits?

[Jon474]

I have just harvested and washed, with sterile water, the WLP002 from my last brews.

When it has settled out I get this...



I can see three distinct layers. The pale yeast-coloured layer at the bottom, the dark, quite sinister, middle layer, and the watery, in-suspension, remnants of yeast at the top. I managed to filter this brew well when transferring it to the FV and, consequently, I did not have too much trub coming through into the FV and only a reasonably small amount of cold break material. The pale yeast was in abundance and there was loads of it. It even began to ferment in the collecting vessel during the two hours after I had collected the slurry from the FV. It tasted great too. I love tasting yeast!

So, what is the dark, sinister layer?

It seems inverted to me.

What have I created?

Thanks in advance.
Jon

[Aleman]

You want the bottom layer . . . the dark layer at the top is 'dusty' yeast, less flocculant mutants,

[Jon474]

Aleman

Many thanks. That fits in with what I hoped/thought.

I have looked at other websites describing how to wash yeast and received the message that the bottom layer is full of rubbish and dead stuff and so should be thrown...but in this case that did not seem true. The good stuff is definitely the pale slurry.

I'll re-wash later and get rid of the top two layers.

Thanks for the reply.
Kind regards
Jon

[Aleman]

When You do it without filtering the bottom layer is often dark brown, with subsequent washings it goes similar to what you have . . .often with brown flecks (break proteins) in it. I rarely do more than two washes

[Wolfy]

I can see three distinct layers. The pale yeast-coloured layer at the bottom, the dark, quite sinister, middle layer, and the watery, in-suspension, remnants of yeast at the top. I managed to filter this brew well when transferring it to the FV and, consequently, I did not have too much trub coming through into the FV and only a reasonably small amount of cold break material. The pale yeast was in abundance and there was loads of it. It even began to ferment in the collecting vessel during the two hours after I had collected the slurry from the FV. It tasted great too. I love tasting yeast!

So, what is the dark, sinister layer?

It seems inverted to me.

What have I created?

There was a recent, similar and quite heated discussion on exactly this question on the AussieHomeBrewer forums.
My conjecture is that the bottom layer is clean and healthy yeast and it's what you want to collect, I'd even go so far as to suggest the darker layer is dead yeast cells, proteins and other gunk you don't want.
The few times I've washed yeast it's always looked like the bottom layer you have there and it's always taken off into good healthy ferments.

In regard to comparing it to yeast-washing pictures and tutorials, my suggestion is that it's possible they are American and that their malt leaves much more trub and other gunk that settles to the bottom - where as you suggested most of that has already been filtered out.

[Jon474]

Thanks guys. I'll do a second wash tonight and remove the gunk.

I reckon I'll have about 1.2L of good quality slurry after the washes - I have 2 x 2L flasks full of WLP002 slurry.

I'm going to restart about 300ml in a 2L starter for the weekend and "bottle" the rest into 300ml quantities in sterilised brown bottles plus crown caps and store in the fridge. These will get used up in the next three weeks.

Thanks again.
Jon

[Wolfy]

I'm going to restart about 300ml in a 2L starter for the weekend and "bottle" the rest into 300ml quantities in sterilised brown bottles plus crown caps and store in the fridge. These will get used up in the next three weeks.

If the yeast has just been freshly harvested and washed, there is no need or reason for a starter.
The yeast is not going to be any more healthy than it already is, simply pitch the appropriate quantity (which is fairly easy to determine when dealing with washed and concentrated yeast slurry).

You may even find a large amount is still healthy and viable after being stored for 2-3 weeks.