- To get your brine ready, boil the water, remove it from heat, stir in the salt, and allow to cool to room temperature (should take about 30 minutes).
- As you wait for the brine to cool, cut up and peel the hard green part of the rind using a vegetable peeler.
- Place the cut pieces of watermelon rind into a pint-sized jar along with the garlic cloves (and mustard seeds/dill if you’re using it).
- Once the brine is cool, pour it into the jar until it’s near the lid. I like to put a small dish into the jar in order to push everything down and keep it submerged in water, but it’s not totally necessary for a short ferment like this one.
- Store in a dark place (preferably pretty warm) for three days and taste it.
- Allow the rind to ferment for two more days. After five days the watermelon will have taken on a yellowish hue and a slightly pickled taste, and will have softened enough to eat while keeping a nice crunch to it.
The rind should stay nice and crisp in the fridge for about three weeks.