For the BBQ sauce: In a stainless steel saucepan, combine the apple juice concentrate, ketchup, vinegar, brown sugar, Worcestershire, bacon fat, mustard, salt, garlic powder, cinnamon, cinnamon sticks, star anise, bay leaves, clove and nutmeg. Bring to boil over high heat, stirring constantly. Simmer for 25 to 30 minutes, then strain. Cool in an ice-bath before refrigerating.
For the beer can chicken: Rinse the chickens well, then place them in the brine and refrigerate for six hours.
Remove the birds from the brine and pat dry, especially in the cavity. Place the birds on a rack set over a baking sheet and refrigerate, uncovered, for six hours. Next, rub the birds with the spice rub, inside and out, making sure to get into all the cracks and crevices.
Pour off 6 ounces of beer from each of the cans. To each can add 4 ounces of the apple BBQ sauce, 2 ounces of the cranberry juice and 1/2 teaspoon of the herbes de Provence. Mount the birds atop each beer can and tuck the wing tips behind the breasts. Stand the mounted birds on a smoker rack and smoke over a mixture of hickory and applewood at 250 degrees F until the birds reach an internal temperature of 165 degrees F, about 3 to 4 hours. Allow the chickens to rest for 20 minutes before cutting into pieces.
Serve the birds with the gravy from the beer cans on the side. ENJOY!!