I've had a few batches get a little too carbonated in the bottle. Currently, I have a delicious stout that fills two glasses on pour, and needs some time to settle down. That is, of course, if you open it over the sink and don't create a mess all over the kitchen.

I'm pretty sure I know why this is happening, but as it's happened more than once, I'd love some input as to possible reasons why. And no, I'm not shaking the bottles. It's not a violent explosion, more of a steady... plume.