Sour Watermelon Rind Candy

Method

1. Peel the outermost green peel off of your leftover watermelon rinds and cut them into ¼-inch thick slices with a knife or a mandoline.
2. Place the rinds in a shallow container and pour the sugar over the watermelon rind slices, then stir to coat. Cover and refrigerate for a minimum of 6 hours, or overnight.
3. Transfer the watermelon rind and all of the liquid into a medium-sized saucepan over medium heat. Add 1 cup of water to the saucepan. Bring the mixture to a boil, stirring occasionally.
4. The water will boil off for about 15-20 minutes or so, and in the process the watermelon will become glassy and translucent. Keep cooking until the temperature reaches 235˚F - 240˚F, about 10-12 minutes.
5. Move to a wider, shallower pan over low heat. Stir frequently and keep a close eye on the mixture. If you start to get a burnt sugar smell or golden brown color, remove from heat immediately, stir, and then return to low heat in a minute or two.
6. Keep stirring until the sugar starts to dry out and crystallize on the watermelon rind. Once you see the sugar has mostly crystallized, add 1 tablespoon of citric acid to the candied rind and stir to coat.
7. Transfer the candy out onto a wire baking rack set atop a sheet pan, and use tongs to unfurl any pieces that have curled up during the cooking process.