Why a Paper Bag Helps a Banana Ripen Faster

If your bananas are looking a little green and you’re feeling impatient, a paper bag is all you need to achieve perfect ripeness.

Have you ever taken a bite from a banana and it just… didn’t taste like a banana? You might notice that the bunch you bought from your local grocery store still looks a little green, is stiff to the touch, and may even taste slightly bitter. Bananas are harvested and often sold while they’re still unripe. As they ripen and mature, the fruit becomes softer and sweeter.

This is why green bananas won’t taste good. When they’re ready to be eaten, bananas are bright yellow with a few brown spots. And when they’re mostly brown and overripe, they’re exactly what you need for recipes like banana bread, muffins, or pancakes.

The process can take several days to a week. If you have a hankering for banana bread, it can be hard to wait for your bananas to reach the perfect level of ripeness. Fortunately, there are ways to speed up the process, and the easiest involves something that probably came with the bananas when you purchased them: a paper bag.

What makes a fruit ripe?

Quick science lesson: Bananas are climacteric fruits, which means that they can ripen after being picked off the branch.

Climacteric fruits produce a plant hormone called ethylene, which is important in the ripening process. As the fruit matures, it produces more ethylene, which triggers and aids in the ripening process. As it ripens, starches are converted to sugar, acid levels are reduced, the flesh softens, and the color of the fruit grows darker.

Interestingly, this happens with all fruits, but bananas and apples produce large amounts of ethylene. This is why putting them next to other climacteric fruits like mangoes, avocados, or papayas will cause them to ripen faster. It’s best to separate these fruits, unless you actually want them to ripen quicker.

Another quick tip: if you want bananas to ripen slower (AKA prolong their shelf life), separate them from the bunch. This will stall the ripening process, and you’ll be able to snack on them for longer!

Why a paper bag works

Putting bananas in a paper bag and loosely folding the top concentrates the ethylene gas. The ethylene gas will circulate, and depending on their current stage of ripeness, your bananas should be ready in a day or two.

If you have other climacteric fruit that you want to eat sooner, you can also put them in the paper bag with the bananas and speed up the process. Two birds with one stone!

Paper bags work great because they trap ethylene while still letting oxygen in, which is essential for the chemical processes involved in ripening. If you happen to be out of paper bags (because maybe your cat’s favorite hobby is ripping them up) you can also use a plastic bag. Just make sure to leave it unsealed, and know that there’s less oxygen going in, so it might take a few days longer.

Other ways to “ripen” a banana

Some sources may advise you to cook unripe bananas in the oven to get them ready for baking purposes. It works in a pinch, but doesn’t actually ripen them.

Remember our science lesson? Fruits like bananas produce hormones and gasses to assist in ripening. Cooking them can’t replicate that natural process. But it can help get the right texture and bring out a bit more flavor.

If you have yellow bananas that are already sweet, but maybe not soft enough for baking, you can put them in the oven at 150˚C until the skin turns black for about 20 minutes. This will make the flesh softer, a little bit sweeter, and perfect for that banana cake that you’ve been wanting to bake!

This won’t work with green bananas, though. Roasting them will make them soften and turn black, just like yellow bananas, but it won’t make them any sweeter. If you use them for baking, you’ll end up with something bland, missing that distinct taste of banana that you’re craving. In this case, it’s better to practice a little bit of patience and stick with the paper bag trick.

Now that you know how to get perfectly ripe bananas, here’s what you can make with them: