To freeze grapes for snacking: Wash the grapes on the stem and pat them dry. Place them in the freezer for 2 hours, then enjoy.
To freeze grapes for longer term storage: Remove the grapes from the stems, wash them and pat them dry. Place them on a baking sheet in a single layer and flash freeze for 1 hour. Transfer to an airtight container or freezer-safe plastic or silicon bag. Mark a “Use By” date that is 10 months in the future and place in the freezer. You can use frozen grapes directly in smoothies; no need to thaw.