Wash the watermelons and prick them in several places. Pack them tightly into a barrel. Through the spigot hole in the bottom, pour in the brine (50g of salt per 1 liter of water). Let them ferment at room temperature for up to 48 hours, then move them to a cool place. If desired, you can add 2-3g of cloves and 1g of cinnamon for every kilogram of watermelons.