Firehouse Jack's Mustard BBQ Sauce

Source: Jack McDavid, owner of Jack's Firehouse in Philadelphia - From Barbecue Bible by Steven Raichlen

3/4 cup distilled white vinegar

1/2 cup beef or chicken broth

1/2 cup finely minced onion

1/4 cup seeded minced jalapeno chilies

1/2 cup Dijon mustard

1/4 cup honey mustard

1/4 cup corn syrup

2 tablespoons molasses

1/2 teaspoon black pepper

1/2 teaspoon coarse salt

1/4 teaspoon cayenne pepper

Combine all ingredients in a heavy nonreactive saucepan over high heat and bring to a boil. Reduce heat and simmer until thick.