Here is a recipe for Grape Cooler. It uses grape juice, whey, and salt. I have done this with grape and apple juice. It should work with cherry juice also. If the cherry juice ferment fails, you may have to try it again with an apple juice\cherry juice mix to give it enough sugar to ferment.
One litre (quart) of juice, 1 teaspoon of Sea Salt , and 2 Tablespoons of whey. Put all ingredients into a glass bowl, cover loosely and let sit for 3 days. Skim the scum off the top and refrigerate.