The idea is ANY oxygen that touches the product once you start grinding your grains is bad, full stop. The dilemma is yeast need the O2 to regenerate enough to ferment appropriately. So, what I've been reading and hearing through podcasts and such (since I don't do LoDo cuz it's a ton of extra work and my beer wins awards without that, plus I don't really do the German / Bohemian Pilsner thing which is where that seems to truly shine), is that adding O2 an hour or two after pitching yeast, once they've theoretically scrubbed the trace amounts of it from beer, will be consumed really quickly and you've severely limited your O2 exposure. Vs adding O2, then adding yeast and waiting for them to get trucking. That extra 2 hours is potentially a source of oxidation.Same here. But then the low oxygen group avoids oxygen getting in throughout the mash and other steps prior to fermentation. So...