You may not have heard of how Ethylene Gas affects fruit, but you have likely been a victim of its quick action more times than you can count. Ethylene gas is the natural hormone emitted by fruit as it ages. It is responsible for turning your perfect bunch of bananas into prime bread material overnight.
When fruits are immature they have low levels of the Ethylene gas hormone. To induce quicker ripening a fruit will increase its hormone production. Not all fruits rely on this system though.
Fruits such as bananas, peaches, avocado, apples, mango, pears, and plums will continue to ripen with time after harvest due to natural processes such as the release of ethylene. Other fruits such as cherries, grapes, and strawberries do not rely on post harvest ripening requiring them to fully ripen on the plant before being picked.
While this natural process can inhibit the use of your produce on your timetable, it can be manipulated to more quickly ripen store bought produce. Because this natural hormone can quickly spoil a large harvest, many fruits are harvested immature to allow for necessary shipping and processing times to get the procude from the farm to your table without spoiling.
To more quickly ripen your fruit simply use a paper bag to trap the ethylene gas as it is released to trigger the natural maturing and ripening process post-harvest. Place multiple fruits in a bag to increase the amount of gas released.