TO BRINE THE TURKEY:
Dissolve the salt, sugar and juice concentrate in 1 quart of hot water. Cool the solution with 3 quarts of cold water.
Remove the giblets (and any other foreign matter) from the turkey interior and place in the cooler. Pour in the brine mixture to cover. If the bird is not completely submerged, add more liquid. (Since I don't want to weaken the solution, I use canned broth.)
Cover with ice, close the lid and soak the turkey for 6-8 hours. (Exact soak times will vary per your taste. Start with 6 hours and make changes to subsequent birds.)
TO ROAST THE TURKEY:
When the bird has half an hour left to soak, move the oven rack to the lowest level and preheat the oven to 500 degrees.
Remove the turkey from the brine and pat dry with paper towels. Rub the turkey liberally with canola oil. (Be sure to get all the nooks and crannies around the wings.) Discard the brine and thoroughly wash the cooler.
Place the turkey on a roasting rack inside two disposable aluminum roasting pans.
Roast at 500 degrees F for a half-hour. Remove the bird from the oven and reduce the oven temperature to 350 degrees.
Cover the turkey breast with a double layer of heavy-duty aluminum foil folded into a triangle. Insert a probe thermometer into the thickest part of the breast (push it right through the foil) and set the thermometer to 161 degrees. A 14- to 16-pound bird should arrive at the target temperature in 2 to 2 1/2 hours.
Remove the turkey from the oven, cover the bird and the pan loosely with aluminum foil and allow to rest for 15 minutes before carving.