Combine first five ingredients in large roasting pan. Place brisket in the marinade, fat side up. Cover tightly with foil. Marinate in refrigerator for 24-48 hours. When ready to cook, place pan covered in foil into a 300-degree oven. Cook brisket for approximately 40 minutes per pound, about 6-7 hours.
When fork-tender, transfer whole brisket to a cutting board. Slice against the grain and place slices back into the cooking liquid. Serve immediately, spooning juice over the slices.