01 - Place grapes, water, sugar, and lime juice in a blender.
02 - Blend on high speed until completely smooth and frothy.
03 - Pour the mixture through a fine mesh sieve or cheesecloth into a pitcher, pressing to extract all liquid and remove solids.
04 - Taste the beverage and add more sugar or lime juice as needed to achieve desired flavor balance.
05 - Refrigerate until cold or serve immediately over ice cubes in tall glasses.
06 - Decorate with fresh mint leaves or additional grapes if desired.