Here's another one by Jess Caswell. This one is very tasty, believe me. A pretzel's best friend!
¼ cup – Yellow Mustard Seeds
¼ cup – Brown Mustard Seeds
½ cup – McClary Bros. Apple Pie Drinking Vinegar
¼ cup – Cider Beer
2 Tbsp – Brown Sugar
1 tsp – Kosher Salt
Mix mustard seeds, vinegar and beer into a non-reactive bowl. Cover and let set for 24 hours at room temperature. In a food processor, process the soaked mustard seed mixture, brown sugar and salt for about 5 minutes until thick. The mustard will be grainy. Transfer to a jar and enjoy now. Or, let the mustard mellow for about two weeks. Taste it then and season as necessary. Enjoy!*adapted from The America's Test Kitchen DIY Cookbook by Editors at America's Test Kitchen