Slow roasting a turkey is a great way to prepare your Thanksgiving bird and does not require any expert cooking skills or techniques. Although slow cooking at low temperatures is slightly riskier than cooking at high temperatures, the danger of consuming harmful bacteria is generally considered quite low, especially if you follow all the recommended safety precautions. Slow roasting for many hours will produce a fully cooked bird that's moist and tender, the perfect centerpiece to any meal.
Thaw your turkey completely if it is already frozen. Leave it in the refrigerator in a roasting pan at a rate of 1 day for each 5 pounds of turkey. Avoid other thawing methods, such as using water or microwaving, as these will increase the risk of bacteria.
Preheat the oven to 400 degrees.
Rinse and prepare the bird to be cooked. Remove the giblets and innards manually and wash the entire bird inside and out with cool water. Pat the bird dry and season it as you wish. Don't stuff the turkey if you plan to slow roast it, as this increases the chances of contaminating the dressing with bacteria. Rub the inside of the turkey with butter to prevent it from drying out and cover with aluminum foil. Pierce a few holes in the foil to release the steam.
Add the rack to the bottom of the shallow roasting pan in which you will cook the turkey. Place about double the amount of water or chicken stock you would normally use. This will prevent the juices from evaporating too quickly and burning.
Place the turkey in the roasting pan breast down. Roast the turkey in the oven for about 20 minutes at 400 degrees and then immediately turn the temperature down to 200 degrees for the remainder of the cooking time (about 8 to 10 hours, depending on the size of the bird).
Turn the bird over breast-side up about 90 minutes before serving time. Oil and season the skin according to your turkey recipe and place the aluminum foil back on the bird when you're done. Remove the aluminum foil when there are about 40 minutes left of cooking time to make the skin brown and crispy
Check to see that your turkey is done by using a meat thermometer. The interior part of the turkey needs to reach at least 170 degrees to be considered done. Remove the turkey when it is done or leave it in the oven on a very low heat until carving time.