- 4 pounds watermelon
- 1 serrano chile, thinly sliced, seeds removed if desired
- 1 1″ piece peeled ginger, thinly sliced
- 2 star anise pods
- 4 teaspoons kosher salt
- 1 teaspoon black peppercorns
- 1 cup sugar
- 1 cup unseasoned rice vinegar
- Using a vegetable peeler, remove tough green rind from watermelon; discard.
- Slice watermelon 1″ thick. Cut away all but 1/4″ flesh from each slice; reserve flesh for another use. Cut rind into 1″ pieces. (You should have about 4 cups.)
- Bring chile, ginger, star anise, salt, peppercorns, sugar, vinegar, and 1/2 cup water to a boil in a large saucepan, stirring to dissolve sugar and salt. Add watermelon rind and return to a boil; reduce heat and simmer until just tender, about 5 minutes.
- Remove from heat and let cool, setting a small lid or plate directly on top of rind to keep submerged in brine, if needed.
- Transfer rind and liquid to an airtight container; cover and chill at least 12 hours.
- Do ahead: Watermelon rind can be pickled 2 weeks ahead. Keep chilled.