Mr malty help - how much yeast do I have in this tune?

[philistine]

Hi Guys,

I have a few of these vials full of a yeast that I washed from a brew recently. When they were filled, they're were completely opaque and creamy, but now after 3-4 weeks in the fridge they've settled out a lot and I wanted to re-use some of it. I wont tip out water thats on top becase i'll use it to shake around in the tube to dislodge the thick yeast below
I'm using the Mr. Malty pitching calculator and im on the 'repitch from slurry' tab so Im wondering what settings to use:

"Yeast concentration billion/ml' slider - Im thinking of having it up towards the thick end - say 3.5?

"Non-Yeast percentage" slider. - it's pretty clean yeast, I mean, when I was washing it, I was pretty ruthless when decanting the dark layers of trub/dead yeast and beer. But Im just a bit confused because I dont know if i shoul dfactor in the volume of water in the vial, which would be 50% if I dont remove any....

Thanks in advance!

 

[philistine]

Tube , not tube...

 

[Truman42]

I wouldn't worry about the liquid on top. You have 26 mls of yeast there.
Better to over pitch than under pitch so I would leave the yeast concentration and non yeast percentage as defaults.

If you leave everything at defaults and plug the harvest date in as 1 sept, For a 20 litre 1.048 ale you need 178 billion cells in 139 mls of yeast. So just over 5 vials. So you can pitch 5 vials (139 mls of yeast) if you have them or if not you can make a starter.....

So Mr Malty says you have around 2.1 billion cells per ml in your slurry (178/139 = 2.1 billion cells per ml. X 26 mls = 54 billion cells in that vial of 26 mls yeast.)

If you then head over to yeastcalc.co, and plug in your batch details and an initial cell count of 100 (so approx two of your vials) with today's date as your production date (because you've already factored in the viability from Mr Malty) then plug in a 1 litre starter with shaking as the minimum of aeration you will end up with 197 billion cells which is just over the 179 that you need.

It's a little bit of mucking around but it's a good way to learn a bit more about yeast and pitch rates etc.