Just wondering if you used Concords or some other type of grapes. My juice isn't sweet enough to mix half and half with water.
I ended up looking in the Maker's Diet and seeing that it said to only leave the juice out for 48 hours, rather than the 3 days that NT said. I skimmed it and tasted it and it didn't taste alcoholic, but then I don't drink, so I don't really know for sure. I'll have to let my husband taste it before letting the kids have any.