I screwed up my efficiency by a couple points during my last brew day. I forgot to watch my ph and added about a gallon of extra water to a 5 gallon batch I didn't have time to boil off the extra due to something coming up. Anyways I was thinking of putting my ipa in a brewpot overnight in the freezer to make an EisenIPA. Anyone have suggestions short or blanketing the brewpot with CO2 to reduce oxidation? Ive never attempted anything like this before just heard about people doing it. Any suggestions would be most helpful.