Mistakes that make turkey dry usually trace back to one problem: the lean breast keeps cooking after it is done, while the dark meat takes longer. A roasting chart cannot tell you when the whole bird is ready, so a food thermometer matters more than the clock.
For a conventional oven roast, USDA Food Safety and Inspection Service recommends an oven temperature of at least 325°F. Remove the turkey only after a food thermometer shows at least 165°F in the innermost thigh, the innermost wing and the thickest part of the breast, then let it rest 20 minutes before carving. Below are nine mistakes to avoid, what USDA and university Extension programs say about each, and which popular tips have less evidence behind them.

The short answer: turkey dries out when the lean breast cooks past done. Roast at 325°F or higher, check the innermost thigh, the innermost wing and the thickest part of the breast with a thermometer, take the turkey out once all three read at least 165°F, and rest it 20 minutes before carving.

Key takeaways

USDA says the minimum is 165°F in the innermost thigh, the innermost wing and the thickest part of the breast. Roasting times are approximate, and a pop-up timer alone is not enough.
Breast and dark meat cook differently. NPR quoted chefs saying lean breast overcooks easily, which is why one oven time cannot suit both.
Rest the bird 20 minutes before carving, per USDA and Colorado State. Texas A&M says 20 to 30.
Plan the thaw: about 24 hours per 4 to 5 pounds in the refrigerator. USDA says cooking from frozen takes at least 50% longer.
Brining and basting may help, but the sources differ and we found no controlled test. USDA lists foil tenting as optional.

Why turkey dries out
The NPR story quotes chef Kenji Lopez-Alt saying breast meat is lean fast-twitch muscle with little fat or connective tissue, so it overcooks easily, while dark meat has more connective tissue and takes more cooking to turn tender. That is why most of the mistakes below come down to the breast cooking past done.
Mistakes that make turkey dry at a glance

Mistake
Fix

1. Not planning for a frozen or partly frozen turkey
Thaw in the refrigerator, about 24 hours per 4 to 5 pounds, or allow at least 50% more time from frozen

2. Trusting the clock or a pop-up timer
Use a food thermometer; times are approximate

3. Cooking the breast until the legs are done
Check all three spots; some chefs spatchcock or cut up the bird

4. Checking the wrong spot
Innermost thigh, innermost wing, thickest part of the breast

5. Carving right away
Rest 20 minutes (USDA)

6. Brining the wrong way
Keep it refrigerated, time it, and pat dry

7. Letting the breast overcook while the skin browns
Optionally tent with foil for the first 1 to 1½ hours, then remove it, and keep checking the temperature

8. Stuffing the bird
Bake stuffing separately or accept a longer roast

9. Reheating without moisture
Add broth, cover with foil, reheat to 165°F

The 9 mist 

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