Mix together liquid smoke, garlic salt, celery seed, and worcestershire sauce.
Spread over both sides of brisket and refrigerate overnight.
Before baking, season brisket with salt and pepper. Bake covered at 300° F for 5 hours.
Baste occasionally. During last hour of baking add 1 cup barbecue sauce. Cool for 45 minutes to an hour before slicing. Cut across grain.
Servings: 4