Orange Marmalade (Seville)

Although it's traditionally made with sour orange and lemon, marmalade is open to interpretation.

6 Seville oranges peeled, peels cut into ⅓" pieces, flesh seeded and coarsely chopped
2 Seville oranges quartered, thinly sliced, and seeded
2 lemons, quartered, thinly sliced, and seeded
1½ qts water, cold
sugar

Bring fruit, peels, and water to a boil in a large saucepan. Cook for 5 minutes. Turn off heat, cover, and let cool.

Refrigerate for 8 hours (or up to 1 day).

Freeze a plate. Uncover citrus mixture, and bring to a simmer over medium-high heat. Cook until thickest peel is tender, about 20 minutes. Measure mixture, and return to pan. For each cup of mixture, add 3/4 cup sugar.

Bring mixture to a boil, stirring often. Cook until mixture registers 220°F-222°F on a candy thermometer, about 20 minutes. To test for doneness of marmalade: Drop a spoonful on frozen plate. If marmalade has a slight film when pushed with a finger, it's done. If it spreads out and thins immediately, continue cooking, and test again after a few minutes.

Transfer marmalade to airtight containers, cover, and let cool at room temperature. Refrigerate overnight before serving. (Marmalade will keep, covered and refrigerated, for up to 1 month.)

Makes 2 quarts.