I have been brewing for quite a few years. I would not say that I am a pro, but I like to think that I know what I'm doing. I have an American Amber going in the primary at the moment. I brewed on 2/23 with a starting gravity at 1.036. I have not seen the airlock bubble since I put it in the primary. This concerned me, so I popped the top on the fermenter on 2/25 - THERE WAS KRAUSEN ON THE WORT!!! STILL NO BUBBLING IN THE AIRLOCK, so I get out another package of yeast to pitch again today - 2/27 - pop the top on the fermenter and the krausen is gone and the wort is beginning to smell like beer. So I decide to take a hydrometer reading... 1.012. Just were it should be for racking. I have checked the seal on the fermenter and it checks out. So, my question is... Has anyone ever experienced fermentation without a bubble in the airlock? Or is it possible that it fermented out in one night while I was asleep?