Mix all ingredients for marinade. Marinate whole brisket overnight in refrigerator. Turn several times and pierce with fork. Spoon sauce over brisket. Remove from sauce and scrape off excess. Place on hot grill to sear both sides. Place in foil ware pan; cover tightly with foil. Close hood on barbecue and cook on low about 4 hours until meat is tender. Slice brisket across grain at an angle. Heat remaining sauce to boil and pour over slices.
Serves 16 to 20.