Bananas often turn brown within a day or two of being brought home from the supermarket, but there's an easy way to keep them firm and ripe07:57, 12 Jul 2026Most bananas on supermarket shelves are green, yet rapidly turn yellow once brought home. There's frequently only a day or two before brown spots begin to appear, making them one of the most wasted foods in Britain.‌This is largely because many people tend to avoid eating them once they've gone brown, much like avocados.‌Fortunately, there are numerous ways to slow down this process and keep bananas fresh for up to two weeks. It starts at the supermarket, where you should opt for loose bananas rather than those sold in a bag.‌While many supermarkets are phasing out this type of packaging, bags with holes cause bananas to ripen considerably faster.Bananas, along with many other fruits, produce a gas called ethylene, which accelerates the ripening process, reports the Express.When stored in a plastic bag, this gas causes them to ripen even more rapidly, resulting in brown spots appearing within just a day or two.‌According to a food hygiene expert at High Speed Training, the fruit shouldn't be kept in a bowl either.Instead, bananas should be left on a kitchen worktop, ideally at room temperature and away from any moisture, direct sunlight or heat sources.‌The expert said: "Anywhere too warm will speed up the ripening process, so avoid keeping them near ovens or warm appliances."Separating the fruit from the bunch can also help them stay at their "prime freshness" for considerably longer. The expert explained: "The ethylene gas is released from the stem of the banana, so to slow the impact of the gas and avoid the over-ripening too quickly, you can also wrap the stems in a plastic wrap or cling film."This reduces the amount of gas that will be able to travel down the fruit and therefore allows them to stay fresher for longer."Article continues belowIf this feels like too much bother, consider using a banana tree instead, which helps keep the fruit surrounded by air.Many households also tend to pop them in the fridge once they've hit their peak ripeness.These bananas could remain fresh for up to "two weeks". And don't be deterred by any brown or overly ripe-looking bananas, as the flesh inside will be absolutely fine.