Smoke Grilled Turkey
Make the brine by boiling 1 gallon of water with the salt, sugar, and the sachet. Add that to the remaining gallon of cold water. Chill before using. Fully submerge the turkey in the brining liquid and brine for 24 hours.
Build a fire with wood or charcoal, and let it burn down. After the fire subsides, spread hot coals to the outside of the grill. (If using gas, use the outside gas lines only.) The grill should be at approximately 400°F. Remove the turkey from the brine and pat dry. Brush with rendered duck fat. Place the bird in the center of the grill, away from direct flame, backside-down. Tent the bird on the grill using aluminum foil and tape to secure. Grill for 2½ hours, covered, basting every 15 minutes. Add wood from another fire (fresh wood will flare) as needed to keep the heat constant. (If using charcoal or gas, add soaked wood chips to create smoke.) Roast the turkey to an internal temperature of 150°F. Rest for 25 minutes, carve, and serve.