By Harold McGee
Among all our foods, fruits are unique in the way that they progress from inedibility to deliciousness. Immature vegetables and young meat animals are at their tenderest and most delicate, but immature fruits are usually at their least appealing. We may still eat and enjoy them—green tomatoes, green papayas, green mangoes—but we treat them as vegetables, cut them small for a salad or cook or pickle them. In order to graduate from vegetablehood, fruits must undergo the process called ripening, which creates their distinctive character.