I brewed a batch of Kolsch three weeks ago tomorrow and the air lock is still "fairly" active (a burp every 7 seconds or so). Does Kolsch yeast tend to take longer to ferment out? Not that I'm concerned or anything, I'm in no hurry and am perfectly happy letting it do its thing. I haven't taken a gravity reading and probably won't (would rather let it just work away instead of taking the air lock off and on). I did notice with this yeast it did take a good 2 to 2 1/2 days to take off when I pitched it (I did not do a yeast starter). I've never fermented in my garage before, but have been able to hold a 58-60 degree temperature range pretty consistently throughout the entire 3 weeks.