Why temperature is so important
NB. F = Degrees Fahrenheit and C = Degrees Centigrade
Temperature is critical in determining how long to cook a turkey, for the simple fact that the bird must have reached a uniform temperature of at least 165 F throughout in order to destroy harmful bacteria. You do not want to give your guests food poisoning!
The turkey is a weird shaped food source! - Large body covered with thick flesh around the breast area, large legs made up of dense muscle and a large internal cavity. Because of this, it is not so easy as cooking a single joint of meet for example. The breast meat tends to cook much faster that the dense muscular leg meat, so there is a risk of over-cooking the breast meat whilst waiting for the leg meat to cook thoroughly.
Deciding how long to cook a turkey is not an easy question to answer as there are so many variable factors to consider.
The type of oven
With conventional gas or electric ovens (not Microwave, Convection, Rotisserie) the top of the oven is the hottest zone. The middle part of the oven is usually the coolest zone. The bottom part of the oven is usually also a cool zone in a gas oven, but in an electric oven this area can be a hot zone. As the turkey will remain in the same position throughout the cooking cycle, this will influence the length of time and how evenly the turkey cooks.
Microwave ovens work on an entirely different principle but due to the larger size of turkey compared to chicken, may not be large enough to cook turkey.
Convection ovens are more efficient than conventional ovens because an internal fan circulates hot air all around the food. Turkey cooked in a convection oven should be more evenly cooked with maybe a 50% saving in time.
Rotisserie ovens are also more efficient than conventional ovens because the food is continually turned allowing heat to penetrate evenly.
Size and weight of the turkey
No surprises here, but the larger and heavier the turkey, the longer the time period for cooking! If the turkey is so large that it only just fits into the oven, seriously consider using a bigger oven or buying a smaller turkey. The reason for this is that to cook the turkey thoroughly, there must be a good air space all around the turkey to enable hot air to circulate. If this is not the case then it will be difficult to gauge cooking times and ensure even cooking throughout.
Fresh or frozen turkey?
Many people prefer to cook a fresh turkey as the taste is said to be superior to frozen. Fresh turkey should be purchased 1 to 2 days prior to cooking and stored in a refrigerator. When ready to cook take out of the refrigerator and allow to come up towards room temperature.
Frozen turkey is more convenient for many people however and provided the correct thawing out procedure is followed, should be safe and tasty. Care must taken to follow the suppliers thawing out instructions correctly, including that applying to stuffing. A general guide to thawing frozen turkey stored in a refrigerator is to allow 24 hours for every 4-5 pounds weight (e.g. a 14 pounds turkey would take 3 to 4 days to thaw out).
Deciding how long to cook your turkey
Professional chefs cook their turkey at an oven temperature range 325 F to 350 F (170 C to 180 C).
As a guide, if you are cooking a 12 pounds weight fresh or thawed frozen turkey without stuffing using a conventional oven operating at a temperature of 325 F, the likely cooking time would be 3 Hours. When stuffing is placed within the turkey it will take a little longer to cook through so the cooking time must be increased. Refer to a good turkey cook book for full instructions.
Testing temperature when cooking your turkey
The old school method for testing when your turkey is cooked is to use a clean metal skewer. When the approximate cooking time is up, you take the turkey out of the oven and carefully pierce the thickest part of the leg with the skewer. Remove the skewer and press against the leg to see if the juices run out clear without any trace of pink - if the juices are clear then the turkey should be cooked.
There are more accurate methods available using modern technology, more suited to the amateur or newbie chef:
Use a temperature probe food thermometer designed to be inserted directly into the turkey during the cooking process, as directed by manufacturers instructions. This continuously monitors the internal cooking temperature so you can be certain that the correct minimum temperature is achieved.
Use a thermometer (designed for the specific purpose) to register the internal temperature of your oven so as to check the accuracy of your ovens temperature controls.
When the turkey has cooked and has been removed from the oven, use an "instant read" probe food thermometer to check the internal temperature of various parts of the turkey e.g. legs, inner thigh, breast, internal cavity stuffing. The turkey should be allowed to rest for approximately 30 minutes after cooking and the internal temperature must be at least 165 F to ensure that the meat is cooked sufficiently well and safe to eat.
Turkey cooking tips
Some professional chefs suggest pre heating your oven to a much hotter initial temperature of 425 F ( 220 C ). Place your turkey in the oven and leave for approximately 15 minutes. Then reduce the temperature down to the correct range selected e.g. 325 F for the remaining time. The idea here is to give the turkey a good blast of heat which penetrates right into the meat and any stuffing. Consider cooking stuffing outside the turkey in a casserole. To protect the turkey breast from over-cooking and drying out, consider placing stuffing under the breast skin. You should carefully peel back the skin and work your fingers and then your hand under the skin to free it from the meat. Spoon the stuffing into the cavity and then replace the skin and secure down to avoid anything leaking out.
Enjoy your turkey dinner celebration!
