Cooking Tips
Ripen an Avocado Faster With Help From a Banana
With bananas, a paper bag and a bit of science, you'll have ripe avocados in no time.
Kate Bernot

Avocado ripening seems so fickle, it’s become a meme. The fruit—yes, avocados are fruit—are rock-hard for days when you bring them home from the grocery store. Then, seemingly in a blink of an eye, they’ve gone too mushy. Guacamole lovers like me know the struggle.

But you needn’t stare at the avocados in your fruit bowl for days on end, watching the produce equivalent of paint drying. We’ve got a better way to hasten avocados’ ripening—and all it takes is a banana.

Place unripe avocados inside a paper bag with a banana or two, and you’ll speed up ripening. Moving the bag to a warm spot in the kitchen can add a further ripening boost.

I tried this with one of the fist-sized rocks my grocery store sells as avocados, plus two ripe bananas. Less than two days later, I had taco-ready, ripe avocados. My husband thinks I possess magic fruit-ripening powers, but I actually just used simple science. 

Avocados are what’s called climacteric fruits, meaning they become ripe after they’re picked when the ethylene gas level inside them reaches a certain point. Ethylene gas acts like a plant hormone, signaling to fruit that they should put a little pep in their step when it comes to ripening. As one piece of fruit emits ethylene gas, other climacteric fruits nearby get the message that it’s time for them to ripen, too. It’s peer pressure, for produce. 

Because bananas produce copious amounts of ethylene, they nudge neighboring fruits to hop on the ripening-into-deliciousness train. Triggered by the ethylene gas from the bananas, fruits ramp up their conversion of starches to sugar. 

Cook’s Illustrated editor Dan Souza breaks it down further in this video:

An understanding of climacteric and non-climacteric fruits can make us savvier grocery shoppers. Knowing that climacteric fruits will continue to ripen off the tree or vine, I can buy avocados, apples, mangos, nectarines, peaches, pears, plums, and tomatoes while they’re still a bit hard. But knowing that non-climacteric fruits like grapes, berries, cherries, and pineapple won’t ripen off the tree or vine, I avoid any that are underripe. They’re not going to sweeten up once they’ve left the store.

One last note: If you’ve been dismayed by dense avocados before, you may have heard that placing them inside a warm oven for 15 minutes will ripen them. Don’t bother with this method; we’ve tested it. All we got after 15 minutes were hot and slimy—but still not ripe—avocados. While we love warm dips like buffalo chicken, guac is a dish best served chilled.

Photo: Marko Geber/Getty Images