Which Layer is Yeast?

From the top, the first layer is beer, and then there are 2 more layers. I thought it would be layer 2, but is it possible it is layer 3 (will some yeast settle under the trub?)?

I brewed 10 gallons of an IIPA. I used 2 new vials of WLP007 into a 4L starter on a stir-plate. Fermentation went from 1.077 to 1.024 in 5 days, and then I dry-hopped into bags in the fermenter. I'm using a 14.5 Blichmann SS Conical with tri-clamps. On day 8 I dumped from the 1" bottom into a carboy and added ~80 ounces of water (that I had boiled jars in and cooled to 70) and swirled good. I let that carboy sit in a cool water bath to settle for 20 minutes, and then I slowly poured into 12 8-oz jars which were then capped and put in the refrigerator.

This is the pic after sitting in the refrigerator for 3 hours:




I've read the yeast washing/rinsing thread entirely as well as a few other threads, but this is the first time I've attempted this and I'm not sure its right. Any tips would be greatly appreciated!

Just save the whole thing. It's all yeast (dead and alive). The living / dormant yeast will wake up when you add more wort, and the dead yeast will give the living yeast some nutrients to snack on as they reproduce.

You really can't mess up yeast banking. These things are resilient.

Silentnoiz said:

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The main problem I see is that it really isn't safe to store the yeast next to those bottles of Darkness. The yeast gets scared by the label and kind of mutates into an undesirable form. So, to avoid this mutation, you should send me those bottles of Darkness right away. There's no telling how much damage has been done already. I have a specially designed storage/disposal method in order to deal with problems like this.

allthingsgiant said:

Just save the whole thing. It's all yeast (dead and alive). The living / dormant yeast will wake up when you add more wort, and the dead yeast will give the living yeast some nutrients to snack on as they reproduce.

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So when I use Mrmalty to calculate 'Repitching from Slurry', what values should I use for 'Yeast Concentration' and 'Non-Yeast Percentage' (assuming I don't use the top liquid layer when I pitch)?

signpost said:

The main problem I see is that it really isn't safe to store the yeast next to those bottles of Darkness. The yeast gets scared by the label and kind of mutates into an undesirable form. So, to avoid this mutation, you should send me those bottles of Darkness right away. There's no telling how much damage has been done already. I have a specially designed storage/disposal method in order to deal with problems like this.

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You're right! I'll take care of that promptly...as soon as they finish aging for at least 2 years...probably longer since I have a little 3-year 2-deep vertical going.

Silentnoiz said:

So when I use Mrmalty to calculate 'Repitching from Slurry', what values should I use for 'Yeast Concentration' and 'Non-Yeast Percentage' (assuming I don't use the top liquid layer when I pitch)?

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Your guess is as good as anyones.

The number of cells in a slurry vary quite widely, and it's almost impossible to get right with the sliders. For example, "think slurry" of WLP004 is about 400 billion cells per liter, while WLP566 is 2000 billion per liter.

Viability in the fridge doesn't change much over time.
http://woodlandbrew.blogspot.com/2012/12/refrigeration-effects-on-yeast-viability.html


There are other much larger contributes to loss viability such as fruit and alcohol.
http://woodlandbrew.blogspot.com/2012/12/how-fruit-effects-yeast-viability.html

For ABV, the numbers I have show 10% viability loss for ever ABV percentage over 6% ABV

Depending when you use this yeast to repitch (2 weeks, 2 months), you'll have different viability levels. To ensure a proper fermentation, just make a new 2L yeast starter from this, and you'll have a bunch of fresh happy yeast. Don't overthink it by going out and buying a microscope and haemocytometer.

the whiter the better

allthingsgiant said:

Depending when you use this yeast to repitch (2 weeks, 2 months), you'll have different viability levels.

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Actually the viability is about the same at two weeks as it is at two months.

http://woodlandbrew.blogspot.com/2012/12/refrigeration-effects-on-yeast-viability.html

There are much larger factors than time that can affect viability. The biggest I have seen are fruit and alcohol.

If you don't do a cell count, or have some one do it for you, you can easily be off by a factor of 20. If you use a starter you will be a little better off, but still about a factor of five off.

But a factor of five is not that bad.