STRANGE thing w/Welch's!

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

Yes there was alcohol. the common way to make homemade root beer is to slightly ferment the syrup in the bottle so that it fizzes. You end up with a 1% root beer.

Ray

I would think that you have an old bottle of pasturized grape juice, probably with a bacterial growth. Not a weak bottle of wine.

EEeeww....

aqueous sugar and yeast in the air.

I realize that wine has been made

what is this, innocence of youth??

Would someone explain this to me? I have never seen professionally bottled juice ferment on its own. I realize that wine has been made naturally without convenient yeast we can use today, but how could this have happened without all of the natural things that are good for starting like crushed skins and pulp?