Preheat the oven to 250°F. Spread the peanuts on a baking sheet. Roast for about 20 minutes, or until slightly darker and fragrant.
Add peanuts to a food processor. Process for 3-5 minutes, until nuts have reached a creamy stage. Add the salt, starting with less and adding more until you achieve the desired taste. Process for another minute.
Pour into a 16 ounce jar with a lid and refrigerate immediately.