Ripen/ˈraɪpən/ Definition 1 of 3Pro Tip 1/3Natural Process It emphasizes a gradual, natural change, especially for fruits and vegetables. Keep the avocados in a paper bag to let them ripen naturally. Pro Tip 2/3Time Varies Different fruits and conditions cause ripening times to vary widely. Bananas ripen faster in a warm climate than in a cool one. Pro Tip 3/3Color Change Ripening often involves changes in color, which help to spot ripe produce. Watch as the bananas turn from green to yellow as they ripen.