Watermelon Rind Jam

Take a thick-rinded watermelon, trim away the pink flesh from the rinds, and pare off the tough green outer skin.

Chop the rinds into neat, bite-sized pieces with fluted edges.

Pierce each piece gently with a fork and soak them in a baking soda solution (3 teaspoons of baking soda per 3 liters of water) for 4 to 6 hours.

Rinse the rinds thoroughly, then let them soak in clean water twice, for 30 minutes each time.

Bring the water and half of the sugar to a boil to create a syrup, drop in the rinds, bring back to a boil, and simmer gently over low heat for 20 minutes.

Remove from heat and let rest for 8 hours or longer.

Bring the mixture back to a boil, stir in the remaining sugar, and boil for 20 to 30 minutes.

Let it rest again for 8 hours.

For the third time, simmer until the rinds become translucent and tender enough to bite through easily.

Just before finishing, stir in the lemon zest, freshly squeezed juice of one lemon, and the vanilla.