Spread the peanuts out in a single layer on a tray in warm, dry area. Dry the peanuts in the shell for two to three weeks or until the outer shell is dry and brittle. Purchased peanuts usually do not require drying prior to storage.
Place the peanuts in an airtight container or bag. Seal the storage container so air and moisture don't affect the peanuts.
Store the sealed container in a dark, cool place, such as a pantry. Avoid humid storage areas, as moisture causes the peanuts to rot prematurely.