Remove the turkey from the brine and pat it dry. Let it sit for at least 30 minutes but up to two hours. Preheat the oven to 450°F.
Put the oven in a large roasting pan. Cut the butter into slices and stick it under the skin of the bird.
Cook at 450°F for 25 minutes, and then lower temperature to 350° for 1 ½-3 hours. Use a thermometer to check for doneness: when it reads 165°F internally in 3 spots, it's done.
Let it rest for at least 30 minutes and preferably 1 hour before serving.