Making mustard at home is simple and rewarding, but it does take some time. The mustard seeds must soak in liquid (beer for St. Patrick's Day, of course) for two to three days until the seeds are soft enough to break apart. After the mustard is blended, it tastes quite bitter and needs an overnight rest to mellow. All this waiting around is worth it -- homemade mustard tastes much better than its supermarket counterpart. Also, you can customize your mustard by adding your favorite spices or herbs. I like to include a big spoonful of honey plus a good amount of mustard powder.
Makes about 1 cup
¼ cup brown mustard seeds
¼ cup yellow mustard seeds
2 tablespoons apple cider vinegar
¾ cup beer
1 teaspoon kosher salt
1 tablespoon plus 1 teaspoon mustard powder
1 tablespoon honey
Combine the brown mustard seeds, yellow mustard seeds, apple cider vinegar, beer, and salt in a small, non-reactive bowl. Cover and set aside for 2 - 3 days.
Drain, reserving the liquid. Transfer the mustard seeds to the bowl of a food processor or blender fitted with a metal blade. Stir in the mustard powder and honey. Blend to desired smoothness. If the mustard is thicker than you'd like, add in a little of the soaking liquid. Transfer the mustard to a jar, cover, and store in the refrigerator overnight before serving.
Mustard will keep in the refrigerator for at least a year.