Jamil's pitching calculator and thick slurry

[Kaiser]

Jamil,

on your pitching calculator I noticed that about 420 ml thick yeast slurry are needed to properly pitch a 5.25 gal 12*P lager wort.

In the literature [Narziss] I found that the proper pitching rate is 0.5l/hl which results in about 15 million cells/ml pitched wort. Noonan recommends pitching about 4-5 ml thick yeast slurry per liter of wort. This is about 80-100ml of thick yeast for 20L (5.25 gal).

What is your definition of thick yeast slurry? Could you also add the amount of yeast sediment needed, since I feel that this would be more precise than the volume of a slurry.

Thanks,
Kai

[jamilz]

There are so many factors it is difficult to give a number that applies for everyone. I used Fix's number for cells/ml in a slurry, accounting for trub.

I have a new calculator that allows you to adjust the variables for trub, etc. Once I finish up some other work, I'll get it wrapped up and posted.

I think you'll be much happier with the numbers from the new calculator.

[Kaiser]

There are so many factors it is difficult to give a number that applies for everyone. I used Fix's number for cells/ml in a slurry, accounting for trub.

I have to check Fix on that. Where the numbers taken from the "Brewing Science" book?

I have a new calculator that allows you to adjust the variables for trub, etc. Once I finish up some other work, I'll get it wrapped up and posted.

I think you'll be much happier with the numbers from the new calculator.

Thanks. I have been using this calculator a lot. But since the volumes for the slurries seemed high to me, I simply took an empty White Labs vial, filled it with water halfway full (as much as the yeast sediment in a full vial takes up) and measured the volume of water. I then multiplied this by the number of vials that your calculator came up with. For a 5.25gal 12P lager it came to about 100ml.

Maybe you can take the same approach to determine the volume that a yeast sediment with 1 Billion cells has.

Kai