Store extra pesto in an airtight container or mason jar in the refrigerator for up to one week. For longer storage, you can freeze pesto for up to three months. To freeze individual servings, place the pesto in an ice cube tray and freeze for one hour. Once the pesto has frozen, transfer the individual cubes to a labeled freezer bag along with the date. This makes it easy to grab a cube or two of pesto for quick and convenient use in your favorite recipes.