Blending chunks of watermelon and giving it a quick strain through cheesecloth yields a sweet liquid that is a perfect foil for tart lime juice. It's normal for the watermelon juice to separate a bit in the fridge, but that's nothing a quick stir won't fix.
- Flesh of a 5-pound watermelon, cubed, seeds removed
- 1/4 cup lime juice, from 3 to 4 limes
- 2 tablespoons agave nectar
In two batches, pulse the watermelon cubes in a blender just until it looks like a chunky sauce, about 10 to 12 short pulses. Transfer pulp to a colander lined with cheesecloth set over a large pot, stirring occasionally until most of the liquid has dripped through. Transfer 3 1/2 cups of liquid to a large pitcher and reserve remainder for another use.
Add lime juice and agave nectar to pitcher and stir to combine. Refrigerate until completely cool. Serve in ice-filled glasses, garnished with lime zest or rings if desired.