Place all of your brine ingredients into a stockpot with 4 C of water.
Bring the pot to a boil.
Reduce to a simmer, stirring occasionaly, until the salt and sugar have fully dissolved.
Remove from heat and add 8 cups of cold water.
Allow the brine to cool to room temperature so you do not cook the turkey breasts.
Submerge the turkey breasts in the brine and refrigerate for at least 6 hours or up to a day. The longer you brine, the juicier the meat will get, but also saltier.
Wash the brine off of the breasts in cold running water, when you are done.