Choose 500 grams of fresh, ripe grapes (either green or black variety). Wash them thoroughly under running water to remove any dirt or pesticides.
Remove the grapes from their stems and place them in a blender or juicer.
Blend or juice the grapes until you get a smooth liquid. If you prefer a thinner consistency, you can add 100-200 ml of water while blending.
Strain the juice through a fine mesh strainer or cheesecloth to remove any seeds and pulp.
Pour the strained juice into a serving glass. If desired, add a teaspoon of sugar or honey to sweeten the juice and mix well.
Add a few ice cubes to the glass and garnish with a few fresh mint leaves or a slice of lemon. Serve chilled.