So I have an amber ale that spent a month in primary in a carboy. I had room in the fermentation chamber so I decided to slip it in before bottling to further clear the beer (or see if anything changed). While it cooled I removed the air lock every hour or so just to equalize pressure then replaced it, so as not to introduce sanitizer. After a few of these inverse purges I felt like I may have put my brew in danger of oxygen exposure. This beer is far from expelling CO2 as it is 30+ days old. What do you guys think? Do you do this all the time or did I make a huge mistake?
I feel like I have heard someone say they foil for lagering to avoid the vacuum problems but there is probably still CO2 expulsion to combat that..