If you don't have a meat thermometer and would rather not buy one just for Christmas, there are a few steps you can take to make sure your turkey is fully cooked and not overcooked. According to the experts behind the Turkey Talk-Line at Butterball, this is exactly what you need to do to ensure a fully-cooked yet still moist bird.
1. Find out the cooking time based on the weight of your turkey.
Using the turkey-cooking calculator is the easiest way to find out how long your turkey will need to cook based on its weight. A 9 kilo turkey will take around three and a half to four hours to cook at 170°C.
2. Don't peek!
Although it's tempting to check on your turkey, opening the oven only lowers the temperature and prolongs the process, potentially screwing up your initial estimated time. Keep the oven closed until you're about two-thirds of the way through to check on it for the first time. If the turkey breasts are getting too browned too quickly, cover the turkey in a tent of foil. If they don't look browned, feel free to skip that step.
3. Keep your eye on the thigh.
The deepest part of the thigh muscle is the very last part of the turkey to be done. The internal temperature should reach above 75°C. To check for doneness without a thermometer, pierce the thigh and pay attention to the juices: if the juices run clear, it's cooked, and if the juices are reddish pink, it needs more time. Put the turkey back in the oven and check again after a short time.