How to Make It
In a small saucepan, combine the water with the vinegar, sugar and salt and bring to a boil, stirring until the sugar is dissolved, about 3 minutes.
Layer the watermelon rind, ginger and jalapeño in a 1-quart heatproof glass jar and cover with the pickling liquid. Let stand at room temperature for 3 hours. Cover and refrigerate for at least 12 hours. Drain the pickles before serving.