Calculating Yeast Quantity

[BigFishBrewing]

I have been making starters for the last year using a commercially produced package with a 'known' amount of yeast cells. My brewing buddy got a mason jar of fresh yeast from a brewer and we used it in our last batch. There was about 3/4 of a cup left and so i made a one liter starter today and over the course of the next week I will do a couple more steps. My question is, how do I determine how much I have in my flask when I pitch into my batch next week as I have literally no idea how much I started with. I know how much I need but I don't know how to calculate how many billions of cells are in the flask (2 liter flask).

 

[balrog]

Rule of thumb is you'll end up with 100b for ea 1/2L starter you make, roughly speaking. And that's not terribly dependent on what you start with.

 

[BigFishBrewing]

That's very helpful Thanks a lot!