1. Look for a translucent, yellowish hue rather than a true green for green grapes; a crimson tone for red grapes; and a very dark hue - almost black - for blue grapes.
2. Make sure grapes are refrigerated in the store.
3. Choose wrapped grapes if you have a choice, because they are more protected.
4. Make sure grapes have a silver-white bloom over skin, which indicates freshness and minimal handling.
5. Avoid grapes that are sticky or wrinkled.
6. Pay attention to grape stems, which should be moist and flexible as well as firmly attached to the fruit. The exception to this rule is Emperor grapes, which should have brown woody stems.