Whole Grape Juice in Cider?

[DidgeryDrew]

I ran short of cider to fill my gallon jug, so I added whole grape juice that my neighbor gave me that she made from the grapes in her back yard. The other batch that I started at the same time has already begun fermenting, but this hasn't. Both batches have a cup of white and a half cup of brown sugar in it. Did I just waste my apple juice by adding the grape or will it ferment into something I will want to drink? Thanks in advance!

 

[John53189]

Gravity measurements would answer your question. Could be stuck or slow fermentation.