01 - Combine grapes, cold water, sugar, and fresh lime juice in a blender container.
02 - Process on high speed until completely smooth and frothy, approximately 1-2 minutes.
03 - Pour mixture through a fine mesh sieve or cheesecloth into a pitcher, pressing with a spatula to extract maximum liquid and discard pulp.
04 - Test sweetness and acidity levels, adding additional sugar or lime juice as desired.
05 - Refrigerate until thoroughly chilled or pour immediately over ice cubes in filled glasses.
06 - Decorate each serving with fresh mint sprigs or additional grapes if desired.