Preheat oven to 275°F. In a large Pyrex baking dish, thoroughly mix all ingredients for sauce. Put the brisket in the baking dish, and turn it over once to coat it with the sauce. Seal the dish with heavy-duty aluminum foil. Bake at 275°F for 5 to 6 hours. Remove from oven and allow to stand for 1 hour before slicing. Slice across the grain, and serve with sauce. Makes 8 to 10 servings.