• 1 12-oz. bottle Guinness Extra Stout
• 1 ½ cups (10 oz.) black or brown mustard seeds
• 1 cup red wine vinegar
• 1 Tbsp Kosher salt
• 1 tsp fresh-ground black pepper
• ¼ tsp ground cinnamon
• ¼ tsp ground cloves
• ¼ tsp ground nutmeg
• ¼ tsp ground allspice

Combine all ingredients in non-reactive container. Cover and let sit at room temperature 2 days. Seeds will swell and soften. Place in food processor and process until desired consistency. Usually takes at least 3 minutes of processing. Can use blender instead for smoother consistency. Refrigerate.

Mustard will be very sharp at first but will mellow with time.

Makes about 3½ cups.