Orange Marmalade

Squeeze the juice and seeds from 6 Seville or other sour oranges, halved and 1 navel orange, preferably organic, halved into a mesh strainer set over a small bowl. After all the oranges have been squeezed, place seeds on a piece of cheesecloth, gather up the sides, and tie securely. Cut each rind in half and then slice as thinly as possible.

Put the orange slices in a large pot or a Dutch oven. Add the reserved orange juice and bag of seeds, a pinch of kosher or canning salt, and 10 cups water. Bring to a boil over medium-high heat, then decrease the heat to medium-low and simmer for 20 minutes. Remove from the heat, cover, and let stand overnight at room temperature.

The next day, stir in 8 cups (1.6 kg) sugar and set the pot over high heat. Bring the mixture to a boil, then decrease the heat to medium-low to maintain a gentle simmer. Cook, stirring occasionally to make sure the mixture is not burning on the bottom, until the marmalade reaches the jelling point (220°F on an instant-read or candy thermometer; or use the wrinkle test to judge when it’s done by spooning a drop of the marmalade onto a small plate that’s been chilled in the freezer and pushing it with your finger—if the marmalade wrinkles, it’s ready, if it’s still syrupy, keep boiling). If white scum occasionally rises to the top, skim it off with a large spoon.

Stir in 2 Tbsp. (30 ml) cognac or whiskey (if using) and, using a pair of tongs, remove the bag of seeds, squeezing with the tongs to extract as much marmalade from it as possible. Ladle the hot marmalade into clean jars. Wipe rims clean with a damp cloth, cover tightly, let cool, and refrigerate. Do Ahead: Marmalade can be made 6 months in advance and stored in the refrigerator. After opening, consume within 1 month.