When I popped the top the jug let out a little hiss and had a faintly alcoholic odor. A quick search led me to conclude that the cider was entirely safe to drink, it merely had began to carbonate and start the fermentation process. We were on our way to (accidentally) making hard cider.
Unfortunately that won't be happening now as I transferred the cider to a pair of smaller containers and they will be drank relatively soon, but the carbonation and fermentation process for something like apple cider is incredibly simple and I look forward to reproducing these results again in the future, but on purpose this time!!
Have you accidentally carbonated or fermented a beverage?? If so, how did it taste?