Place the 3-pound trimmed beef brisket into a large zip-top bag. Add 8 ounces Coca‑Cola, 3 tablespoons Worcestershire sauce, and the 3 garlic cloves (mince or crush the cloves so they release flavor). Seal the bag, remove as much air as possible, and massage the marinade around the brisket so it is evenly coated. Refrigerate overnight (about 8–24 hours), turning the bag once or twice if convenient.

The next day, remove the brisket from the refrigerator. Open the bag, discard the marinade, and pat the brisket dry with paper towels. Let the brisket sit at room temperature for 30–60 minutes while you preheat the smoker.

Preheat your smoker to 220°F.

Place the brisket on the smoker grate (fat side up), close the smoker, and smoke until the internal temperature reaches 195–203°F and the meat is probe-tender. For a 3‑pound brisket this is typically about 6–8 hours, but start checking the temperature after about 5 hours because times vary.

When the brisket reaches 195–203°F and is tender, remove it from the smoker, wrap it tightly in aluminum foil, and place it on a rimmed baking sheet. Let it rest, wrapped, for 30–60 minutes.

Unwrap the rested brisket, identify the grain, and slice against the grain into 1/4‑inch slices. Serve.