Prep. time: 15 minutes
Macerating time: Overnight
Cooking time: 30 minutes

White rum has a milder taste, so it's best to use white sugar with it; however, if you choose dark rum, heighten the Caribbean flavor with brown sugar.

Add the rum after the cooking so that the alcohol doesn't evaporate. The alcohol and sugar are the conservation agents in this jam.

1. Trim the watermelon, removing the fiber and seeds; cut the flesh into large pieces.
2. Weigh the flesh to determine how much sugar is necessary (the weight of the sugar should be equal to half the weight of the fruit).
3. Let the watermelon and sugar rest in a bowl overnight.
4. Pour the mixture into a saucepan; simmer over low heat for about 20 minutes or until the watermelon pieces turn translucent.
5. Slice the lemon and orange thinly; it is important to leave the rind on. Remove the seeds.
6. Add to the saucepan and cook 10 minutes longer, stirring often.
7. Ladle the jam into hot sterilized jars and flavor with the rum; add a vanilla bean to each jar; close tightly.

For longer conservation, cover with paraffin before closing.