When roasting a turkey, what temperature should it be cooked to and what is the best way to measure the temperature.--Brenda
Ideally, the meat on the breast of a turkey should be roasted to 165°F (74°C) to be at its most tender. However the leg and thigh need to be cooked slightly higher, to between 175°F (80°C) and 180°F (82°C). At those temperatures, the light and dark meats are at their most tender and moist. Above those temperatures, the proteins start to tighten, squeezing out moisture and leaving the meat drier.
There are a lot of techniques that have been devised for getting around this temperature difference. The Joy of Cooking suggests roasting the bird breast down or on one side for about two hours and then flipping it on its back to finish. In The Way to Cook, Julia Child suggests breaking the turkey down into pieces before roasting. Because the drumsticks and thighs are away from the larger breast, they will cook faster. The cooked turkey can be carved and presented as if it had been roasted whole.
The easiest method is simply to roast the turkey whole and cover the breast with a double layer of aluminum foil for the last half hour or so of cooking.
Total cooking time depends on the size of the bird and whether or not it is stuffed. Smaller birds and those that are not stuffed will cook faster. In general, allow about 15 minutes per pound for a stuffed turkey and about 12 minutes per pound if it is not stuffed. Also, remember to add 20 minutes to a half hour resting time once the turkey comes out of the oven before carving it.
To measure temperature for a whole roasted turkey, plunge an instant read thermometer into the thickest part of the thigh away from the bone, but towards the body and wait until the needle stops moving. If the tip of the thermometer is close to or touching bone, the reading will not be accurate. Measure the temperature of the breast by plunging the tip of the thermometer into the thickest part of the breast, again away from any bone. The temperatures should both be at least those noted above. If you break the turkey down, each piece must be tested for temperature individually.
Also, remember that to be safe the stuffing should read at least 165°F (74°C), measured by inserting the thermometer into the deepest part of the stuffing. See the posting "Dis-dressed Turkey" for more about stuffing safety.
Finally, if your turkey comes with one of those pop-up buttons to show when it is done, still check with a thermometer. The button is only an estimate and may not be completely reliable.