South Carolina mustard barbecue sauce
2/3 cup yellow prepared mustard
½ cup white sugar
¼ cup light brown sugar
1 cup cider vinegar
2 tablespoons chili powder
1 teaspoon black pepper
1 teaspoon white pepper
½ teaspoon cayenne pepper
4 drops Tabasco (I use Louisiana style hot sauce and lots of it instead)
1 teaspoon MSG
½ teaspoon soy sauce
2 tablespoons butter
  1. Combine all ingredients except the soy sauce and butter in a saucepan and simmer 10 minutes. Remove from heat.
  2. Stir in soy sauce and butter.
I added a tablespoon of Tony Chachere's, omitted the white pepper, and used a hearty 3-second armshake of Crystal Hot Sauce. It tastes gooood. The original author of this recipe also suggested the juice of one lime. Sounds great for pork, but I didn't have a lime, so I haven't tried it yet. (Addendum: Tried the lime juice, it's good).