Wash grapes thoroughly and remove from stems. Pat dry with paper towels. Seedless varieties are strongly recommended for freezing since frozen seeds are unpleasant to bite into.
Flash freeze: spread dry grapes in a single layer on a parchment-lined sheet pan. Freeze until solid (2 to 4 hours), then transfer to freezer bags. Their round shape and skin make them naturally resistant to clumping, so they pour freely from the bag.
No sugar, acid, or other treatment is needed. Grapes are one of the most zero-effort fruits to freeze.
8 to 12 months, though they are best within 3 to 4 months for snacking quality.
For snacking: eat directly from frozen. Frozen grapes have a texture similar to sorbet or a popsicle — firm, cold, and sweet. For smoothies: use frozen. For cooking: thaw in the refrigerator.