Wash or rinse the grapes in running water to remove dirt and pesticides from it's skin. Remove stems.Place cleaned grapes in a blender jar.Add 1 cup water, sugar and blend in the blender until smooth.

Place a large fine sieve (a strainer) over a large bowl and pour prepared juice over it. Press the pulp gently using a spatula to get the maximum juice out of it. Discard the solid pulp.