To roast a turkey overnight, cook it at a high temperature for 45 minutes, and then reduce the temperature to 175 degrees Fahrenheit. Cook the turkey for up to 20 hours. The internal temperature of the turkey should register at 170 F before you remove it from the oven.
Roast a turkey overnight by first seasoning and preparing the bird. In a bowl, mix together 1 tablespoon of dried thyme leaves, 1 tablespoon of dried basil leaves, 1 1/2 teaspoons of dried rosemary leaves, 1 teaspoon of dried marjoram leaves and 1 teaspoon of crumbled rubbed sage. Season the mixture with 2 teaspoons of sea salt and 1/2 teaspoon of freshly ground black pepper. Rub the mixture over the entire turkey, and allow it to marinate in the refrigerator for several hours.
Prior to cooking the turkey, remove it from the refrigerator, and allow it to reach room temperature. The timing varies from 90 minutes to a few hours depending on the size of the bird. Place the turkey on a rack in a roasting pan, and drizzle it with oil. Before going to bed, roast the turkey for 45 to 60 minutes at 450 degrees Fahrenheit to brown the bird. Add apple cider vinegar and seasoning to the turkey and pan, and reduce the temperature to 170 degrees Fahrenheit. Slow roast the turkey for one hour per pound.