South Carolina Barbecue Sauce

   150ml                yellow prepared mustard (French's)
   100g                 white sugar
   50g                  light brown sugar
   225ml                cider vinegar
   2      tablespoons   Chili powder
   1      teaspoon      black pepper
   1      teaspoon      white pepper
   1/4    teaspoon      cayenne pepper
   4      drops         Tabasco sauce
   1/2    teaspoon      soy sauce
   2      tablespoons   butter

Combine all ingredients except soy sauce and butter in saucepan and simmer 10 minutes. Remove from heat. Stir in soy sauce and butter. May be used as a basting sauce for barbecue meat or as a condiment when served with grilled pork, beef or chicken.