The Kolsch I started on Sunday 5/4 is my third go at home brewing. I discovered this morning I didn’t have the lid on the fermenter down all the way. I haven’t seen any bubbles from my airlock. I pushed the lid down and I’m going to let it set for the 4 weeks before I bottle. Did I ruin this batch by not getting the lid on correrctly?
Don’t worry about it, it is very unlikely that anything got in and infected it, especially as the lid was on well enough that you didn’t notice it wasn’t sealed. That’s why you didn’t see activity in the airlock by the way, the CO2 was escaping from around the lid (and blowing any microorganisms away).
You’re fine, no worries. Good idea leaving it for 4 weeks – that’s how long I primary my kolsches as well, minimum.