Grolsch bottle bomb after 1yr+

One of my Grolsch bottles exploded. It was bottled more than a year ago with a Vanilla Porter. Most of the other bottles have been drank and were fine. As are the remaining bottles. Temperatures are no higher than normal.
My thoughts are that if it was infected it would have exploded long ago.
Anyone care to guess why a bottle would explode after so long ?

It got lonely sitting there for a whole year, watching it's compatriots being selected and opened month after month. Couldn't take the rejection any longer.

;P

Seriously, no idea. Figured it woul dhave gone off before that. How carbonated were the others? Any possibility it got knocked and maybe dinged the glass a little?

Infections are very rare, and when they *do* occur, they usually take many months to develop. In a 'hostile' environment - under pressure, acidic, alcoholic and hoppy - I find it extremely plausible that it was contamination that caused an infection and blew up the bottle. The entire batch may well have been infected, and you just drank them all before any noticeable off flavours developed. Or, maybe the single bottle was contaminated by some crud of some sort.

I'm guessing you bottle condition with corn sugar or similar, right? I have had this happen in the same type bottles. Its either 1) that one bottle was weak, and the glass couldn't handle the pressure or 2) when bottle carbonating that one bottle had more sugar mixed with the beer and develop a higher pressure than the others.

It happens. Nothing you can really do about it. Hell, it was only one bottle. Oh, most likely had nothing to do with infection.

I used cane sugar. The ones not yet drank are fine but I'll need to keep a close eye on them. Thanks for the replies - all theories make sense.