Fresh peanuts make the best boiled peanuts. Make sure the peanuts are thoroughly rinsed and then soak them in cold water for 45 minutes. Put the peanuts in the cooking pot, taking care that they are completely submerged in water. Add one cup of salt per gallon of water. Cover and cook on high heat for four hours or until desired firmness. Boiled peanuts are a treat but will spoil quickly. Freeze any peanuts that cannot be eaten within a day or two.