01 - Combine grapes, water, sugar, and lime juice in a blender. Blend on high speed until completely smooth and frothy, approximately 1-2 minutes.
02 - Pour blended mixture through a fine mesh sieve or cheesecloth into a pitcher, pressing firmly to extract all liquid while removing solids and skins.
03 - Taste the agua fresca and add additional sugar or lime juice as needed to achieve desired sweetness and balance.
04 - Pour over ice cubes in glasses. Garnish with fresh mint sprigs or additional whole grapes if desired. Serve immediately while chilled.