Sam. wrote:I was under the impression the reproduction phase will continue until all oxygen is used up :-B
I think that is a common myth that is widely reported to be true when it isn't. Whether yeast is respiring with or without oxygen it can reproduce. All the respiration is for is energy, and whilst with oxygen present the yeast is more efficient it can certainly operate without it and reproduce.
It seems the yeast stop reproducing when a certain factor of the environment is reached. In most cases (non controlled growth) this would be the removal of all nutrients which support growth. In our cases as brewers with a decent fermentation I suspect it is likely ph, or some kind of chemical messaging system the yeast use to indicate how packed the environment is with yeast. ie the other by products from the yeast activity. Something that as distillers we probably want to limit as much as we possibly can because it no doubt increases the heads/tails component.
Here is a page about it which kinda goes into it. https://www.morebeer.com/articles/how_yeast_use_oxygen
Definitely anyone wanting a neutral spirit wants to limit the reproduction phase as much as possible because this is where a lot of fusels and other things are generated. This means pitching a lot of yeast, the exact amount I have no idea about yet but I hope to find out for Lowans sometime soon. I'm not sure exactly how this info plays into whiskey/rum/scotch/ etc , I don't have much experience with that. I definitely know for beer you don't want to pitch too much because you'll get a flat taste so I'm figuring, loosely, that the same applies to anything you want a "taste" in.