- Slice the watermelon lengthwise into slices 1 to 2 inches thick.
- Carefully cut away the rind and discard.
- Place as much of the fruit as will fit into a food processor and process until smooth, about 15 seconds.
- Press through a fine sieve and discard seeds and pulp.
- Pour the juice into a pitcher.
- Repeat this process until all the watermelon has been blended and sieved.