In a colander, wash the peanuts in cool water until the water runs clear. Allow the peanuts to sit in room temperature water for 20 minutes to further clean the peanuts. Drain the peanuts in the colander and give them one final rinse under running water.
In a large dutch oven or stock pot, add the peanuts, salt, and water. Bring water to a boil and reduce to medium-low heat. If peanuts are green, it takes several hours less cooking time (1 to 3 hours of simmering). Raw peanuts should boil to perfection in 6 to 7 hours, depending on how dry the peanuts are. Check water levels every half-hour and make sure it stays the same throughout the entire cooking process. Check on the green peanuts for doneness and seasoning after one hour. To check for doneness, crack the shell and eat the peanut. If it is crunchy, let it cook for another hour and repeat until you are satisfied. They are done if the texture of the peanuts is like that of cooked peas. If it needs more salt, add 1/4 cup and continue cooking. If you are cooking raw peanuts, check for water levels after one hour and for doneness and seasoning after 2 hours.
When the peanuts are done, allow them to cool in the pot with the water for at least one half hour. Store peanuts in a container or a zip-top bag in the refrigerator for 7 to 10 days, or freeze in freezer bags for 3 to 6 months.