How much yeast is in my White Labs homebrew PurePitch®?
The wording on our PurePitch® packaging - 'Made to Contain over 100 Billion Cells' - is a target cell count number for each of our yeast packages. We specifically say, “Made to Contain” because not all packages will contain more than 100 billion cells even though we target that number in our production and packaging processes. This is because the reality of cell biology is that cell sizes vary, cell packing varies, and since cells are microscopic, those small variations lead to large fluctuations in cell numbers.
Although the PurePitch® packages state a cell net volume of 35 mL - the packages contain a minimum of 40 mL. With the actual volumes ranging from 40 to 50 mL. Due to this reality, we will be adjusting the stated net volume on our packaging to reflect the 40 mL amount.
In our production, we allow for cell counts of 2.0 to 3.0 billion per milliliter which will produce 80 to 120 billion total cells if 40 mL. We target the high range of cell counts and fill volumes in our production and packaging processes. However as stated above, the reality of cell biology is that those numbers will vary.
We publish the QC data that includes the actual cell count of each lot on Yeastman.com. We state on Yeastman.com the allowed cell count range (2.0 to 3.0 billion per milliliter) because it accurately reflects the reality of packaging microorganisms.