Although I've done quite a few batches of beer, this last batch was the first time I ever used a yeast starter. It's a Belgian Strong Ale and had an SG of 1082. The first 24 hours this thing went like mad. The airlock was literally boiling and the krausen blew the airlock apart. Over the next few days it slowly died down to 2 or 3 bubbles per minute and then to one bubble every couple of minutes. But three times now, when it seems as though it's about at the end of its fermentation, it picks up again to a bubble every couple of seconds! I know that the airlock isn't all that reliable but it is quite odd that it is having bursts of creating more CO2. Of course I'll just let it go for however long it takes. I just found this really weird because I have never seen it before. Using a yeast starter really seems to change the fermentation process. For the better, of course!