Black raspberry kvass is a kid-friendly fermented fruit drink that is easy to make at home. It's also a healthful alternative to commercial sodas.
Place raspberries and honey (no need to heat, it will dissolve) in the jar and add water up to one inch below the top of the jar. Like so:
Leave the jar at room temperature for 2-3 days to allow it to ferment. Each day the water will take on a darker purple color from the infusion of the black raspberries.