Remove the skin from the turkey breasts and put in a small bowl and cover it with plastic wrap. Set aside in the fridge until tomorrow.
In a large stockpot big enough to fit the turkey breasts, add 2 cups of water and the salt and sugar. If your turkey is "pre-seasoned" or "butter-ball", reduce this amount by half.
Heat the water over high heat until the sugar dissolves. Remove from the heat and add 10 cups of COLD water to lower the temperature. Add the turkey breasts and make sure they are fully submerged; if not, add more water.
Brine in the fridge for at least 24 hours and up to 72 hours.
Place the turkey breasts in a single layer in a sous vide bag. Add the melted butter. Seal the bags and cook in a 145°F water bath for 6 hours until cooked through.
Remove the turkey from the water and allow it to rest at room temperature for 15 minutes before carving. There will be a lot of liquid in the bag, you can save it for making gravy.
For the crispy skin, dry the skin with paper towels. Lay the skin flat on a baking sheet lined with parchment paper. Place another piece of parchment on top of the skin, and place another baking sheet on top. If you have something heavy like a cast-iron pan, place that on top as well to weigh the baking sheet down. Bake at 350°F for 40-60 minutes until it is golden brown all over.