Pour beer into a small bowl, cover loosely and let stand at room temperature overnight. Whisk beer and remaining ingredients together in a large saucepan over medium-high heat. Bring to a boil, whisking constantly. Remove from heat; cool to room temperature. Store in an airtight container in the refrigerator. Serve with pretzels and sausage.
NOTES : Give the gift or spicy Beer Mustard with some Bavarian-style pretzels and astick of sausage in a decorated basket lined with a pretty cloth napkin ornew dish towel.