So I brewed a IIpa with an OG of 1.078 Its been about 3 1/2 weeks since pitching the yeast. I used 1272 American Ale II. I took a gravity reading a few days ago and it was 1.012, and again today and it is at 1.012. The beer tastes fantastic and seems like it should be done but when I look at the bottom of the carboy I see little yeast bubbles shooting up from the bottom like a lava lamp. They shoot up, then stall and fall back down. My gravity reading indicates the beer is done but it looks like there is still fermentation going on?