To freeze pesto, store it in an airtight container for up to three months. For easy portioning, spoon the pesto into an ice cube tray and freeze until solid. Once frozen, transfer the pesto cubes to a sealable plastic bag or airtight container. When you’re ready to use them, simply thaw a cube and stir it into soups, pasta, eggs, sandwiches, or roasted potatoes for a quick burst of fresh flavor.