Differences between cultivars may include the date the fruit ripens, disease resistance, freezing quality, firmness, berry size, berry shape, and flavor.
en.wikipedia.org Because mature fruits will continue to ripen when picked, the harvest can be timed to allow for transportation to market.
en.wikipedia.org At the time of "veraison", when the grapes first start to fully ripen, there is the equivalent pyrazine level of 30 ng/l.
en.wikipedia.org It can grow up to tall, and has edible sweet-flavored fruits that are red when young and become purple or dark-blue when they ripen.
en.wikipedia.org Uniform shape, color, netting, and ripening is secured by turning the fruit every few days.
en.wikipedia.org