A dry brine turkey is essentially a salted bird. You use approximately one tablespoon of salt for every five pounds of turkey. So a fifteen pound turkey requires about three tablespoons of salt. If your weight doesn’t divide equally into multiples of five, no worries. You can make an educated guess and it will work out fine.   You can add other flavors in with the salt such as citrus zest and dried herbs and spices. (more on that below). Then you use your hands or a mortar and pestle to mix it all together before you rub it on the turkey.