To slow roast a turkey, roast the seasoned turkey at 450 degrees Fahrenheit for up to one hour, then continue to roast at 175 degrees until the internal temperature reaches 170 degrees. The initial high temperature seals in moisture and the low roasting temperature prevents the turkey from overcooking.
Season a 15-pound to 25-pound turkey inside and out with salt and pepper. Poultry seasoning can also be rubbed into the turkey cavity. Dry the skin by refrigerating the turkey on a roasting rack in a roasting pan, uncovered, for 12 to 24 hours. A dry skin ensures that it will crisp well during roasting. Drizzle the turkey skin with oil and roast the turkey at 450 degrees Fahrenheit for 45 minutes to one hour, until the skin is golden brown. Pour 1 quart of apple cider over the turkey and season the liquid in the pan with a few pinches of poultry seasoning. Reduce the heat to 175 degrees Fahrenheit and roast the turkey for one hour per pound.
The turkey is done when the inside of the leg measures 170 degrees Fahrenheit with a meat thermometer. The turkey can roast longer without drying out. Serve the turkey with the apple cider skimmed pan juices.