Wrapping the stems of bananas in tin foil can slow the ripening process and keep the fruit fresher for longer, according to food advice. The foil traps ethylene gas, a natural plant hormone released mainly from the stem, which is responsible for accelerating ripening and causing browning.
Why bananas brown quickly
Bananas typically last between two and six days at room temperature, depending on how ripe they are when bought. Once fully ripe, they begin to turn brown within a few days as their texture and taste deteriorate. Warmer conditions speed up ripening, so bananas may brown faster during mild spells.
The ethylene gas converts starches into sugars and breaks down cell walls, turning green bananas yellow and sweeter, while yellow bananas start to brown. Trapping the gas with tin foil around the stem helps slow this process and extends shelf life.
Expert advice on foil wrapping
Food Republic's online guidance on preventing bananas from ripening too quickly states: “Compared to other fruits and veggies, bananas are one of the biggest producers of ethylene gas, a natural chemical compound that promotes ripening.”
“The majority of this gas is released through the exposed stem of the fruit, which allows a bunch of bananas to continue ripening even after it's picked from the tree. Wrapping the top of your bunch with aluminium helps to trap in some of the ethylene, so it won't escape into the atmosphere and touch the body of the bananas (or other produce you have sitting nearby, for that matter). This slows down browning and gives you more time to enjoy your bunch.”
Alternatives and storage tips
Cling film can be used instead of tin foil, with both typically costing less than £2 at major supermarkets. Once stems are wrapped, bananas should be stored away from other fruit, as the ethylene gas can cause nearby produce to ripen and spoil faster. Apples, pears, and passion fruit respond to the gas, while citrus fruits like oranges and lemons are unaffected.
Experts recommend hanging bananas on a hook to keep them separate from other fruit and prevent bruising caused by leaning against a worktop.
