how many cells in a starter?

**JLem** · 05-09-2009, 03:35 PM

I know that for the best fermentation, you should pitch the right amount of yeast. I've seen Mr Malty Pitching Rate Calculator. However, is the volume of the starter really a good proxy for the number of yeast cells? Doesn't it also depend on how long the starter has been going? The temp? Starter OG? etc...

TipsyDragon · 05-09-2009, 03:43 PM

no the volume is the way to measure the yeast count. a yeast cell is going to take up the same amount of space no matter how long its been, what the temp is, or the OG was. those factors only affect how fast/much the yeast multiply.

beersydoesit · 05-09-2009, 04:06 PM

Jlem I think that is a good question. Obviously the yeast has to have time to reproduce to build the cell count. So time matters. My recall of the life cycle leaves me thinking that cell count will peak in 2-3 days.
The population curve is in any of the books

I think OG is irrelevant from a cell count view provided the volume is large enough. The wee beasties need food.

Also oxygen is important to cell reproduction. Insufficient oxygen can slow cell growth.

**ajf** · 05-09-2009, 05:16 PM

Check out MB Raines, Ph.D. - Guide to Yeast Culturing for Homebrewers - Maltose Falcons Home Brewing Society (Los Angeles Homebrewing), paying particular attention to table 5.

-a.