This is a recipe for NC BBQ sauce that we used to use in a restaurant I worked at a few years ago. It has no sugars in it, which is perfect for me because I prefer BBQ sauces that are not sweet. This is the best NC sauce I've ever had.
Mix black pepper, salt, cayenne pepper and mustard powder.
Add dry mix to 1 gallon of apple cider vinegar in a pot on stove. Heat on medium whisking occasionally. Cook about 10-15 minutes, reducing heat as necessary to keep below a simmer. You just want to heat it enough to help release the flavor of the spices in the vinegar.
Sauce is excellent on pork barbecue or barbecue chicken. Shake well before using.