Step 1 In a small bowl, combine the salt, pepper, onion powder, cumin and garlic powder. Rub the mix into the brisket and let sit at room temperature, 45 minutes to 1 hour.
Step 2 Meanwhile, prepare your smoker or grill to cook over low, indirect heat for several hours. Set up a drip pan underneath where the brisket will smoke, and fill with the beer and water. Shortly before cooking, adjust the heat as needed to maintain a temperature around 250 degrees, and add hickory chips to start smoking.
Step 3Place the brisket (fat side up) in the prepared smoker and cook for 2 1/2 hours. Adjust the heat as needed (add several coals to either side of the grill as needed if using a kettle grill) to maintain the ambient temperature (around 250 degrees); replenish the chips as needed to keep smoking. Baste the brisket every 30 minutes or so to keep it moist.
Step 4After 2 1/2 hours, wrap the brisket (fat side up) tightly in foil and continue to cook over indirect low heat until the meat is fork-tender, 3 to 4 additional hours (time may vary depending on the heat of the smoker and size and thickness of the brisket).
Step 5Remove the brisket from heat and, still wrapped in foil, cover it with a layer of newspaper and kitchen towels to keep warm. Set aside, covered, for at least 1 hour before serving. While the brisket is resting, make the sauce.