Question: When we buy grapes, we wash the entire bunch at once and then eat them over several days. But they always start to spoil before we can finish them. Is this the best way to store grapes?
Answer: No, you should always hold off on washing grapes until you’re ready to eat them.
The reason, as the California Table Grape Commission points out
To keep grapes at their freshest, store them unwashed in a plastic bag in the refrigerator.