4½ hours (including soaking time), plus cooling time
This makes about 100 pieces, depending on size.
Pickling lime can be found at select well-stocked markets and cooking supply stores, as well as online. This preserve has pale amber chunks of watermelon with a marvelous, slightly crunchy texture.
14 cups water, divided
3 tablespoons pickling lime
6 cups sugar
Juice of ½ lemon
White rind of 1 medium watermelon (green skin and all red flesh removed)
1. Fill a stainless steel
or other nonreactive pot or container (do not use aluminum) with 12 cups of water. Stir the pickling lime into the water. Set aside for 1 to 2 hours, then pour the clear water into another nonreactive pot or container (discard the lime at the bottom). Set aside for another hour to give the remaining lime time to settle, then pour off the clear liquid into another nonreactive container, discarding the lime at the bottom.
2. Cut the watermelon rind
into finger-sized chunks or pieces and toss them into the strained water. Set aside to soak for 3 to 4 hours, then drain and rinse thoroughly several times.
3. Meanwhile, in a medium, heavy-bottom pot,
combine the sugar with the remaining 2 cups of water. Heat over medium-high heat until the sugar dissolves and the mixture comes to a boil. When the mixture begins to thicken, add the lemon juice and bring to a boil again. Carefully add the watermelon chunks. Simmer over medium heat until the pieces take on an amber shade and are mostly transparent, about 45 minutes. Remove from heat. Strain the watermelon pieces using a slotted spoon and set aside to cool on a sheet of parchment paper.
Each of 100 pieces: