Cut 2/3 of the cantaloupe into small pieces.

In a blender, combine 1/3 of the cantaloupe, 2 tablespoons of walnuts, the sugar, and 2 cups water (about 500 ml). Blend until smooth to make a concentrate. Set aside.

In a pitcher, add the concentrate to 8 1/2 cups water (about 2 liters), along with the chopped cantaloupe and the remaining ground walnuts. Stir well with a spoon and serve.