Oxygen and Yeast Growth

[mwth0mas]

I am trying to tune my wort oxygenation rate by looking at yeast growth at the end of fermentation. Is there any quantifiable rule of thumb to determine how much growth is too much outside of repitch viability and flavor impacts? Should I be looking at pitch volumes vs harvest volumes, or cell counts during peak fermentation?

For example, (understanding this will be yeast/gravity/flavor dependent), 9.5bbls of 12 plato wort, pitched 3 gallons at 1 mil cells/ml per plato, I harvested/tossed close to 16 gallons of yeast at the end of fermentation.

I am thinking I am oxygenating too much, and have excessive growth for this particular American Ale strain. Looking for any feedback on how y'all are judging yeast growth and processes for tuning wort oxygenation without an O2 meter.


Eternally grateful,

[a10t2]

2-3 doublings is a normal fermentation, so if the yeast before and after are about the same thickness, you're fine. Without cell counts, though, you don't really know how much you're pitching/harvesting.