Originally Posted by gregfreemyer
If you read the article, it supports my statement. The article states that yeast will use oxygen whenever it is available, and that yeast use up all the available oxygen in wort about 30 minutes after pitching.
Yeast's hunger for oxygen while reproducing is why stir plates are so valuable for creating starters. A stir plate keeps yeast suspended AND aerates the starting medium.
From your referenced article:
Originally Posted by Referenced Article
It is well-documented that yeast uses oxygen whenever it is available, even during fermentation, and yeast cells rapidly absorb essentially all of the oxygen made available to them. Yeast, however, will use the overwhelming majority (if not all) of the available oxygen in biosynthetic reactions, not for respiration.*
The dissolved oxygen levels in wort drop from saturation to near zero very quickly after pitching yeast, usually within 30 minutes under ideal conditions, because yeast absorbs the oxygen for eventual membrane biosynthesis. The oxygen enables the cells to grow much faster and to reach a higher cell density. This effect is not the result of respiration but is the result of oxygen providing the means for sterol synthesis. In the absence of sufficient preexisting wort sterols, oxygen is limiting at this point; in other words, without it, the yeast will starve.
And just to reiterate, I'd previously brewed about 17 batches of beer total over the last 2 years. This is however, only my third batch of all grain. I'd never worried about stuff from the boil getting into the fermenter, and I don't use hop bags, or go to convoluted measures to only put clear wort into the fermenter. It's just that this time the cold break was at least 4 times the amount I was used to seeing. I'm realizing now that it wasn't too much, just much more than I'd previously experienced.
I'd decided that racking off certainly wouldn't hurt, especially with an active fermentation happening, and proper sanitation.
I really only posted to find out if my measures were necessary, or to confirm what I already suspected: That the cold break was fine, and racking off wasn't really needed.
Anyway, thanks for confirming what I expected, that I just had a dumb-ass panic moment.