Any idea what causes the insane amount of foaming that occurs w/ some bottles? I opened one of my Father-in-law's bottles (Sam Adams Clone) a few months ago and it foamed right out of the bottle. I thought it was altitude, but we're lower than he is. I helped a friend brew a few weeks ago and he had the same problem. It doesn't happen w/ the whole batch, just one.
I want to say I've had this happen w/ commercial beers, but I'm not sure. Any thoughts?