Grapes+apple juice

I wanted to know is what taste it would be if I'd add up some apples to grapes juice ( I used dark red grapes). One big apple ( around 250g) and 0.5 kg of grapes=0.5+ liter of juice. very nice. before I made grapes juice but I had to dissolve it with some water because it was too sweet, now adding an apple all became as it should be, not too sweet. An apple I used was of a sweet taste too, still it softened extreme sweetness of grapes.