I've grilled many turkeys on my Webber Kettle Charcoal grill. It always comes out very juicy and tender. Through experimentation, I have found that the cooking temperature is less important than is the final meat temperature. With the oven, I have cooked at various temperatures, from 275'F to 475'F. always to an internal meat temperature of 155'F and then let the bird rest for 15 mintues. The only difference was in the crispiness of the skin. The meat was very tender and juicy no matter what the cooking temperature was.
If using a charcoal kettle-style grill, like a Webber, then divide the charcoal into two banks, opposite each other. Light them and let get hot while preparing the bird. The turkey should be at room temperature. I usually take the neck, gibletes, and liver and make a turkey broth from them to inject into the bird, but that is optional.
I have barbecued my turkeys using just charcoal, and with add ed wood chunks, usually comprised of sugar maple, white birch, or apple, or a combination of all three. both methods, with, and without wood gives an extraordinary result.
Dry the bird thoroughly with paper towels and rub with oil or softend butter. Make a drip pan from heavy-weight aluminum foil, or use a disposable bread pan. Fill the pan half full of water and place between the beds of glowing charcoal. Tie the wings and legs against the body and cover the wing tips with foil. Insert a meat thermometer into the thickest part of the breast meat, with the tip pushed down near the leg joint, but not touching any bone. Cover the face of the thermometer with foil to keep it from being fouled by the smoke. Place the bird directly over the drip pan and place cover on the grill. Close all vents to the half open position. Let cook for about twelve minutes per pound. When the time has elapsed, Check the thermometer. Continue checking evey ten minutes until the thermometer reads 155'F. Remove the bird to a platter and let rest for 15 minutes. The outside heat will continue to soak into the bird, bringing the final temp. to 165'F. REmove the breasts whole, and slice against the grain. Arrange on the platter with the legs and drumsticks on either side. Garnish with leafy greans. Serve with sides.
If using a multi-burner gas grill, follow the same cooking method by plaing the bird over the unlit burner and a smoker box over the ignited burner. Cooking time should be similar.
Total cooking time for a 20 lb. turkey is about 200 minutes, give or take a few.
You can brine your bird to give it extra flavor, or inject it with turkey broth, or a flavored broth where herbs have been added. You can also fill the turkey cavity with aromatics such as onion nad garlic, sage, thyme, etc.
The turkey, once cooking, virtually cooks itself with no required intervention by you, only to check the temperature near the end of cooking time. It's nearly foolproof. And, it will make you the hero of the house.
If you search through the pictures, I have a picture of a barbecued turkey that I made on the Webber. I cooked one on the 4rth for a potluck I attended. It was the star of the event. It really is easy. Do it once and you won't believe how simple a turkey is to cook to perfection.
Seeeeeeya; Goodweed of the North