Wash or rinse the grapes in running water to remove dirt and pesticides from its skin. Remove stems.
Place cleaned grapes in a blender jar.
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. You can also use muslin cloth or nut-milk bag to strain the juice.