How to cook
Take the rind of a thick skinned watermelon. Peel the outer green part thinly.
Measure the weight of the rinds and for every 2 lb (1 kg) watermelon peels, be sure to have 8 1/3 cups (2000 g) of sugar.
Chop the watermelon rinds finely and boil them in water, while changing it out twice, for 3-4 minutes each, while also pouring cold water over them. Then drain them and spread them onto a large platter or tray. Put them in the sun to turn white.
Boil a thick sugar syrup and add the watermelon rinds to it. Boil the jam on a hot stove until the syrup thickens. For each 2 lb (1 kg) of sugar, put 1 teaspoon citric acid.
For watermelon rind jam, the citric acid is added earlier during the boiling process than in other jams. At the end of cooking, flavor with vanilla and a little bergamot essence.
After the watermelon rind jam thickens, you can add lemon slices or geranium.
Distribute the jam into jars, close them immediately and turn them upside down.