Anyone do cell counts on their starters? I've started out of curiosity, but the results are different than what I'd expect.
I've been growing up yeast for a 10 gallon batch of Pilsner this week. The cell counts I'm getting are lower than what I expect based on both the starter size and the volume of yeast I ended up with. I know these are both guesstimates, and I was wondering if anyone else had similar experience or if my counts just aren't accurate.
- Began with 1 vial of WLP830
- Starters contain 1 g/10ml DME.
- 2 stages: 1.6L for 48 hours, then chilled, decanted, and pitched into 4.4L
- Aerated with pure O2 for 60 seconds, fermented on stir plates at ~ 75dF, breathable foam stopper
I chilled the final starter and the compressed cake at the bottom looks to be 200-250 ml based on rough eyeballing. According to Jamil's calculator using the "repitching from slurry" tab, this should be about 700 - 900 billion yeast cells even if it has a high amount of non-yeast material (break). This is the amount that his and the wyeast calculator predicted for me as well.
Problem is, every time I do a count I'm consistently estimating that there are 400 - 500 billion cells in the starter. The starter was still on the stir plate and I didn't see a lot of flocculation. I took a decent sample from near the middle of the flask using a thief, diluted 10x, and counted. I can post the specifics of my calculation for a Neubauer-improved hemacytomer when I get home if that would help.