Is it possible that the juice actually
fermented on its own?

yep, happens all the time. and there WAS alcohol in it I guarantee.

--
billb
"At my comp" wrote in message
...
This is very odd and I realize it probably sounds like a joke, but I
just found an unusual bottle of old Welch’s grape juice with foam!
(I was cleaning and rearranging things in my room a couple months ago
and I accidentally left it in my closet.) The bottle seemed to bulge a
little and there was a pressure like gas when I opened it! I took a
taste and it seemed like a thick and dark sparkling juice/soda, but no
taste of alcohol (unless it is masked by the fizz?) I know that I did
not put anything in the bottle.