My wife loves to drink raw unfiltered natural apple juice. It comes in a clear gallon glass jug. The jug was taking up too much space in the fridge so I transferred it to one of my growlers and put it in my mini beer fridge, we forgot about it for about a month and a half.
So today I am kegging a stout, saw the old growler and thought, “this is old, I better toss it.” As soon as I cracked the cap CO2 came gushing out and foam like a champagne bottle, it smelled like nice apple juice. So we tried it, this sickening sweet flat apple juice has become a nice effervescent but still lightly sweet beverage, seems fairly low in alcohol.
I did not inoculate it with yeast, but maybe the growler had some ale yeast in there, but still seems unlikely as the temp in the fridge should have been too cold for an ale.
Ah well, it was a happy surprise, glad I caught it before the bottle exploded. Wifey is now enjoying it and glad to have it. Darn, now I will probably have to figure out how to recreate said accident. :?