Beef brisket is a very affordable and forgiving piece of meat to bbq. The brisket comes from the chest of the cow so it is a very large and tough muscle that requires long and slow cooking.
I start with the large primal cut that comes in its original packaging. These usually weigh 12-18 lbs. I would say that the main factor that limits when you can cook a brisket is the cooking time. I started with a 15lb brisket and ended up with a total cooking time of about 12 hours. Start by washing the brisket and seasoning with salt, pepper, and garlic powder. You can also use your favorite bbq rub in this step. Keep in mind that most commercial bbq rubs contain a large amount of sugar that will burn on the grill. This will require you wrapping the brisket up with foil to protect it sooner than normal.
For cooking such a large piece of meat the grill needs to be well preheated. We are looking for 225-250 degrees Fahrenheit. I use both the side fire box and the main chamber on my grill. Once the grill is up to temperature and the dampers are closed down it will maintain its heat for several hours at a time. Having the extra coals in the main chamber come into handy for cooking appetizers or other side dishes over direct heat if so inclined. You will need to check and add fresh coals to the to the grill every 1-2 hours during the cooking process to maintain a constant temperature. The first 2 times that I add fresh coals I also add some mesquite wood chips that have been pre-soaked in water.
Above is the brisket after 8 hours of cooking with indirect heat. At this time you will notice that the outside of the brisket starts to form a thick layer that is called "bark". To prevent the brisket from overcooking and also to further aid its cooking, we wrap it in foil. This process is known as the "Texas Crutch" on the competitive bbq circuits. This is similar to the process I use with my ribs. I wrap the brisket up in heavy foil with equal parts apple cider vinegar, apple juice, and water. Make sure that the brisket is well wrapped and no liquid escapes. The brisket is then left on the grill over indirect heat for 2-3 more hours. After a few more hours on the grill the brisket should be done. I like to unwrap the brisket and give it one last quick sear over direct heat to give it a good final crust on the outside. Remove the brisket from the grill and tent with foil to rest for 30 minutes to 1 hour.
Thinly slice the brisket across the grain to serve. It will be pull apart tender, and juicy. You can serve it with your favorite bbq sauce if you want, but it really does not need any.
***Notice the pink ring around the outside of the meat. This is from the smoke penetrating the meat while cooking.