01 - Combine grapes, cold water, sugar, and fresh lime juice in a blender canister.
02 - Blend on high speed until completely smooth and frothy, approximately 45-60 seconds.
03 - Pour mixture through a fine mesh sieve or cheesecloth into a clean pitcher, pressing solids to extract maximum liquid. Discard grape pulp and skins.
04 - Taste the strained beverage and add additional sugar or lime juice as needed for desired sweetness and tartness.
05 - Pour over ice cubes in tall glasses. Garnish with fresh mint sprigs or additional whole grapes if desired. Serve immediately.