Recipe Watermelon Preserves

Dice the white watermelon rind into small cubes, leaving the red flesh intact and removing seeds. In a heavy stockpot, combine 4 cups of the prepared watermelon with sugar and lemons. Bring to a boil over medium heat and simmer for about 2 hours, stirring occasionally, until the mixture reaches 220 degrees F (105 degrees C). While the jam boils, sterilize jars and lids in boiling water for 5 minutes. Carefully pack the hot jam into the sterilized jars, leaving 1/4 inch of headspace. Remove air bubbles with a spatula, wipe the rims, and secure the lids. Process the jars in a boiling water bath for 10 minutes, ensuring they are covered by at least 1 inch of water. Allow the jars to rest for 12 to 24 hours, then check the seals before storing in a cool, dark area.