Remove giblets from turkey breast, if turkey breast contains them.
Place breast in a lidded container big enough to hold the breast and that will also fit in the refrigerator.
Pour brine over breast, making sure to get all of the rosemary, garlic, peppers, and peppercorns into the container with the turkey.
Close lid.
Refrigerate for a minimum of 12 hours, and up to 2 days.
The night before cooking, remove turkey from brine and pat it dry.
Place it on a cooling rack set over a sheet pan.
Place it uncovered in the refrigerator overnight.
Set your turkey out of the refrigerator about 45 minutes - 1 hour before roasting to allow it to come to room temperature.
While turkey is coming to room temperature, heat oven to 425℉/220℃.
Melt butter.
Place cheesecloth in melted butter, turning so that cheesecloth can soak up all the butter.
Place turkey on roasting rack.
Drape buttered cheesecloth around the turkey breast, covering as much as possible.
Place turkey in oven.
Cook for 30 minutes.
Reduce heat to 325℉/165℃.
Continue cooking for an additional hour or until internal temperature registers 165℉/74℃.
Allow to stand for at least 10 minutes before slicing.