Why does Propel Water turn into alcohol after about a year?

Question

My friend left a Berry Flavored Propel water in his closet for a year and about 2 months and it turned into alcohol. I know it's crazy but i have no idea why???

Answer 1

I highly doubt that is correct. I order for alcohol to be nade, fermentation is required. While propel has sugar which would be a necessary ingredient, there is nothing to turn the sugar into alcohol (yeast).

Answer 2

Maybe it's made with real berries, in which case they probably fermented.