Green seedless grapes are table grapes carried by most grocers. They are pale green, sometimes oval shaped. Each grape is juicy, the taste a sweet/sour blandness.
Visible discoloration or mold is bad. The skin of each grape should feel swollen, not wrinkled or mushy. Sweet grapes have a yellow glow. The faint white powder, called bloom, is only a protection against decay, and is edible. Keep grapes refrigerated until they show signs of withering, usually after a week.
Rinse grapes before consuming. They can also be dried into raisins, fermented into wine, or sliced into fruitcake.