Grapes will not become any sweeter after they have been harvested. When selecting grapes, look for those that are bright and well-colored for their variety. Green grapes will have a slight yellow undertone when ripe.
To test for freshness, pick up a bunch of grapes and shake them very gently. The grapes should remain on the stem. Grapes that drop off the stem have been in storage too long and will not last long in your refrigerator. Grapes should be bright and plump, not shriveled.
Remove any damaged or shriveled grapes prior to storage.
Grapes need cold temperatures and high humidity. After damaged grapes have been removed from the bunch, place the grapes in a perforated plastic bag (usually this is the type of bag in which they are sold). Place in the coldest part of the refrigerator where the grapes should keep for up to five days.
Do not wash the grapes prior to storage. Wash them just prior to use. The easiest way to do this is to use a colander and wash the grapes under cold running water.
Frozen grapes make a refreshing summer snack. They may also be used as decorative ice cubes!
