So I have a lager going that I pitched about 4 days ago. I made a big starter using lots of o2 and a stir plate. LOTS of o2. I would have been scared to light a match in the room it was in, but anyways that's not why I'm posting. Except to say I'm pretty sure I proved you can't kill yeast with to much o2.
But the yeast is going strong at 50F in my 7cu ft keezer with the lid closed. I opened it to take a smell and when I put my head in it I could tell the amount of co2 was very high. The fermentation is going strong right now but is keeping the keezer lid closed with nowhere for the co2 to vent a possible issue? Anyone have any experience with hurting their yeast this way, if thats possible?