Thanks to watermelon's natural sweetness, this drink doesn't call for sugar.
Source: Martha Stewart Living, July 2011
Yield Makes 6 Cups; Serves 6
4 pounds watermelon, peeled and cut into cubes (12 cups)
1 tablespoon plus 1 1/2 teaspoons fresh lemon juice
2 1/2 teaspoons finely grated (preferably on a Microplane zester) lemongrass
1 1/2 teaspoons finely grated (preferably on a Microplane zester) fresh ginger
Garnish: trimmed lemongrass stalks
Puree watermelon in a blender until smooth. Strain mixture through a fine sieve into a pitcher. Stir in lemon juice, lemongrass, ginger, and 1/8 teaspoon salt. Refrigerate until chilled, about 20 minutes.
Divide juice among 6 ice-filled glasses, and garnish with lemongrass stalks.
Storage: Juice can be refrigerated for up to 3 days.