When to take a cell count sample

[seattlefng]

So, for those that do cell counts on harvested yeast, when do you grab the sample? Why do you take it at that point? And how do you feel that sample represents total harvest? Taking multiple samples is not a practical option in our case, so we try to take one sample for every harvest and correlate cell counts with performance as best we can. Performance still varies periodically, just trying to rein in another variable.
-thanks.

[GlacierBrewing]

So, for those that do cell counts on harvested yeast, when do you grab the sample? Why do you take it at that point? And how do you feel that sample represents total harvest? Taking multiple samples is not a practical option in our case, so we try to take one sample for every harvest and correlate cell counts with performance as best we can. Performance still varies periodically, just trying to rein in another variable.
-thanks.

I would take samples prior to every pitch (when I worked for this other brewery) on the volume we were pitching.. We also would perform an acid wash at that time. Got to where I could get a cell count down in about six minutes!

ah, good times.......

Prost!
dave

[seattlefng]

Thanks Dave-
We usually harvest one brink for every intended pitch. We use the cell count to determine harvest weight which is the eventual pitch weight. We don't do a viability test (we have in the past with very consistent results, and nothing seems to have changed since, so we don't), so we rely pretty heavily on that cell count. Were you doing a viability test?
I like that idea, we could harvest, agitate the entire harvest and presumably get a more accurate cell count for adjusting the pitch amount. Am I getting the idea?

[GlacierBrewing]

I like that idea, we could harvest, agitate the entire harvest and presumably get a more accurate cell count for adjusting the pitch amount. Am I getting the idea?

Well, that's what I used to do: take a yeast sample, count it, viability-test it, determine pitch rate, harvest pitch rate, acid wash it, and pitch!
Of course, I had to plan ahead in my brew day to make sure the timing was right. The management insisted on an acid wash every time. Wondered if that was really necessary, every time.

Prost!
Dave