GUINNESS MUSTARD

Makes about 3 1/2 cups

1 (12-ounce) bottle Guinness Extra Stout

1 1/2 cups brown mustard seeds (10 ounces)

1 cup red wine vinegar

1 tablespoon kosher salt

1 teaspoon freshly ground black pepper

1/4 teaspoon ground cinnamon

1/4 teaspoon ground cloves

1/4 teaspoon ground nutmeg

1/4 teaspoon ground allspice

Combine all ingredients in a nonreactive mixing bowl. Cover with plastic wrap and let sit at room temperature for 1 to 2 days so that the mustard seeds soften and the flavors meld. Transfer the mixture to the bowl of a food processor and process, stopping occasionally to scrape down the sides of the bowl with a rubber spatula, until the seeds are coarsely ground and the mixture thickens, about 3 minutes. Transfer to a jar and cover.

Refrigerate overnight and use immediately or refrigerate for up to 6 months. The flavor of the mustard will mellow as the condiment ages.