step 1
Line extra-large pot with two 13-gallon plastic bags, 1 inside the other (or use a brining bag).
step 2
Simmer Apple Cider (4 cups), Kosher Salt (1 1/2 cups), Whole Allspice (1/4 cup), and Bay Leaves (8) in a 20-quart pot for 5 minutes, stirring until salt dissolves.
step 3
Remove from heat, add remaining Apple Cider (8 cups), and Water (16 cups). Pour brine into the plastic bag.
step 4
Wrap turkey neck and refrigerate. Submerge Whole Turkey (1) in brine to cover completely, gathering bags tightly to eliminate any air; tie bags closed. Refrigerate turkey in brine in the pot for at least 18 hours and up to 20 hours.
step 5
The next day, line a large roasting pan with 4 layers of paper towels. Remove turkey from brine and drain well; discard brine. Place turkey in prepared pan. Cover with plastic wrap and refrigerate overnight.
step 6
Combine Chicken Broth (4 cups) and Apple Cider (2 cups) in a heavy large saucepan. Boil until reduced to 3 cups, about 20 minutes. Pour broth reduction into a bowl.
step 7
Melt Unsalted Butter (1/4 cup) in the same saucepan over medium-high heat. Add All-Purpose Flour (1/4 cup) and stir for 1 minute.
step 8
Whisk in broth reduction, then Whipping Cream (1/2 cup), Calvados Apple Brandy (2 Tbsp), Italian Flat-Leaf Parsley (2 Tbsp), Fresh Thyme (2 Tbsp), Fresh Sage (2 Tbsp), Fresh Marjoram (2 Tbsp), Fresh Rosemary (1 tsp), and Ground Nutmeg (1 tsp). Bring to a boil.
step 9
Reduce heat to medium-low and simmer until gravy base is thickened and reduced to 2 3/4 cups, whisking often about 20 minutes. Cool gravy base, cover, and chill.
step 10
Position rack in the bottom third of the oven and preheat to 350 degrees F (180 degrees F).
step 11
Remove turkey from roasting pan; drain any accumulated juices from the main cavity. Discard paper towels from the roasting pan. Return turkey to prepared pan. Tuck wing tips under; tie legs together loosely to hold shape.
step 12
Place some Granny Smith Apples (2) and Onions (2) in the main cavity. Scatter remaining apples and onions around the turkey in the pan. Add reserved turkey neck to the pan along with Chicken Broth (1 cup)
step 13
Fold a 2-yard piece of cheesecloth to create a 4 layer rectangle. Dampen the cloth with water and wring out.
step 14
Melt Unsalted Butter (2 sticks) and then submerge the cloth in the melted butter, making sure it is completely saturated. Drape over the top of the turkey, covering it completely.
step 15
Roast turkey for 1 hour. Baste with Apple Cider (1/2 cup). Roast turkey for 30 minutes.
step 16
Baste with remaining Apple Cider (1/2 cup). Roast turkey, basting every 30 minutes with pan juices for another 1 1/2 hours.
step 17
Very gently remove the cheesecloth from the turkey, taking care not to tear the skin. Baste turkey one more time, then return the turkey to the oven and roast until a thermometer inserted in the thickest part of a thigh measures 170 degrees F (77 degrees C), about another 30-45 minutes.
step 18
When done roasting, transfer turkey to a platter; let stand at least 30 minutes before carving (internal temperature will rise 5-10 degrees).
step 19
Discard apples, onions, and turkey neck from the pan. Pour pan juices into a large glass measuring cup; spoon off fat from the surface.
step 20
Pour degreased juices into gravy base and bring to boil over medium-high heat, whisking occasionally. Boil until gravy thickens enough to coat a spoon and is reduced to 3 1/2 cups, about 15 minutes. Season gravy to taste with Ground Black Pepper (to taste).
step 21
Serve turkey with gravy.
