MAKES ABOUT 2 1⁄2 CUPS
Once a barman's staple, orange bitters—a potent concoction of botanicals used to deepen the character of many cocktails—is nowadays hard to find. The simplest way to enjoy this homemade version is to stir a teaspoon or two into a glass of tonic water; you can also use it to complete any number of cocktails, such as the manhattan, the dry martini, and the Fitty-Fitty. The process takes over three weeks, but it's well worth it.
4 seville oranges
2 whole cloves
2 whole coriander seeds
1 whole allspice
1 cardamom pod
1 pint 90-proof vodka
1. Preheat oven to 175°. Scrub oranges well; remove and reserve the whole peel. (Save orange segments for another use.) Finely chop peel into 1⁄4" pieces and spread out on a baking sheet in a single layer. Bake peel, turning 2 or 3 times with a spoon, until almost completely dry, about 2 hours; let cool.
2. Put peel, cloves, coriander seeds, allspice, cardamom pod, and vodka into a large jar. Secure tightly with a lid and set aside in a dark place to let steep for 3 weeks, giving the jar a good shake every day or two.
3. Strain the liquid through a fine sieve into a clean jar, secure tightly with a lid, and set vodka mixture aside.
4. Next, transfer the peel and spices to a small pot, add 1 cup water, and bring to a boil. Reduce heat to low and simmer gently for 15 minutes. Transfer contents of pot to a small bowl, cover, and set aside to let steep for 24 hours. Strain contents of bowl through a fine sieve into the vodka mixture, pressing down on the solids to extract as much liquid as possible; discard solids.
5. Strain the bitters again through 4–5 layers of cheesecloth into a medium bowl, then return to jar. Store for up to 6 months.