Bring water to a boil in a large pasta pot. Dissolve the salt in the water and add the peanuts. Keep them submerged in the brine by taking a plate or pie pan and setting it on top of the floating peanuts. Stir them once every hour over the next 5 hours. Strain in a colander and rinse only lightly.
Place a cooling rack on a cooking sheet. Place the peanuts on the rack in a single layer and allow them to dry for 3 days. Stir occasionally.
Preheat oven to 350 F and roast on rack for 15 to 30 minutes, stirring at the 15 minute mark. The peanuts are ready when they start smelling.