Check your instant-read or traditional meat thermometer a few days before Thanksgiving. If you place it in a pot of boiling water and it registers 212° (water’s boiling point at sea level), you’re all set. If it doesn’t, buy a new thermometer.
Set the turkey on a rack in a large roasting pan to promote maximum air and heat circulation and to ensure that the bird cooks evenly.
Protect the turkey breast from overcooking by roasting the bird on the lowest rack in the oven; this will keep it away from the top, the hottest part of the oven. Once the breast skin is browned, loosely cover it with foil to prevent it from becoming too dark.
Keep a careful eye on the thermometer during the last half hour of cooking since the turkey’s temperature may rise rapidly toward the end.
Check for doneness in the thickest, meatiest parts of the turkey. Using your thermometer, test the widest section of the breast near the wing joint; the temperature should be 165°. Test the legs at the top of the thigh, near the hip joint; the temperature should be 180°. Insert the instant-read thermometer deep enough to reach its heat sensor, the indentation about two inches from the tip. Also check the juices. If they have a pinkish tinge, continue roasting; if they’re clear, the turkey’s done. Try to insert the thermometer as infrequently as possible, to prevent the precious juices from escaping.