Q:

Carbonation and altitude

Can altitude have an effect on carbonation? 
I was at the in laws last week and discovered all of the homebrews I brought (about 6) were foaming over when opened. However, all those from the same batch at home are fine. I know I stirred in the priming sugar consistently, and even if I didn't, the odds that those 6 alone, randomly selected, got over carbonated. The only difference between here and there is about 1000 feet in altitude (in laws being higher). Could that be the cause of the foam spewers?

A:

Apparently the lower pressure can cause the beer to lose carbonation faster, causing foamers. http://www.homebrewtalk.com/f35/effects-altitude-carbonation-1523/
It might also be an infection. Did you notice any change in flavour?

