...Just yesterday I ate oats cold-soaked in apple juice. The lid of the container was bulging or doming, indicating strong microbial activity. The mixture was starting to fizz, and had a little tang. I haven't died yet, but it hasn't been 72 hours either. We won't be holding our breath...
It sure sounds like alcohol was forming from yeast in the apple juice.
I heard a story, don't know if it's true, of the nineteenth century gold rush miners and sourdough bread. They'd drink the nasty black alcoholic liquid from the top of the starter, called "hooch." And that led to the "sourdough" moniker. What a way to get a buzz.