Perhaps I am overthinking this, but do you need to consider reduced viability in subsequent generations of re-pitched yeast, to account for the nonviable portion of yeast that was pitched in the prior batch? Or is the volume of new viable yeast produced in the fermentation enough to make this insignificant, so we can start over with the ~97% slurry viability for each generation (default in Mr. Malty). Unfortunately, I do not have a conical, and while I do separate the slurry from the visible trub, I don't have the ability to harvest the middle of the yeast cone, which I read is often done with a conical. If this has been asked and answered, please share a thread. I did search first and didn't see this.