Watermelon Rind Jam

The limes will make this more fragrant, acidic, and bitter, but you can leave them out if you're looking for something more straightforward and sweet.

Olia Hercules' Watermelon Rind Jam

Makes two 450-milliliter (3/4-pint) jars

• 500grams (1 pound) watermelon skin, tough thin green rind peeled and discarded, white skin finely chopped
• 300grams (10 ounces) golden caster sugar (or substitute superfine sugar or demerara or turbinado, ground fine in the food processor)
• 4limes, halved and thinly sliced (optional, see note in Author Notes above)

1. Mix all the ingredients together in a container, cover with cling film, and leave in the refrigerator overnight.
2. Cook the mixture in a non-reactive saucepan over low heat, making sure the sugar melts before it boils, for 50 minutes or until the watermelon skin turns translucent.
3. Pour into 2 warm sterilized 450-milliliter (3/4-pint) jars, seal and let cool. Store in the refrigerator. It should keep unopened for several months.

https://food52.com/recipes/37659-olia-hercules-watermelon-rind-jam