How To Ripen A Banana Fast

Bananas can be a fickle bunch, so to speak. Notwithstanding attempts by some banana producers to exert a measure of control over the ripening process, grocery store bananas can range from lime-green to canary yellow to mottled yellow to brown. And once you get your bananas home, no matter how green they may have looked at the checkout counter, they'll often ripen faster than you were probably counting on — and, often, all of them at once. 

Thankfully, overripe bananas can still be salvaged for banana bread, for which there is no shortage of compelling recipes. Of course, slowing the process down isn't always the goal. If you're looking to ripen a banana fast, there's always the paper-bag method that ripens most peaches in a matter of days (via Leaf.tv). 

But what if you don't have days? What if you need your bananas not just ripe, but full-on-overripe, and what if you need them that way right now? And by "right now," we mean in about 30 minutes, which happens to be around how long it takes the average oven to complete that all-important step of preheating the oven to your desired banana-bread baking temperature.  

Bananas ripen by producing ethylene gas, which then forms three ripening enzymes (via Leaf.tv). One causes the skin to darken and one softens the fruit. Then there's amylase, which turns the banana's taste from starchy to sweet, to eventually liquid sugar, according to Serious Eats. Amylase is the enzyme that leaves your overripe bananas sitting in a puddle of goo, by the time you get around to checking on them. However, it is also the reason your perfectly over-ripened bananas make for such perfectly sweet, moist, and tender banana bread. 

If only there were a way to harness the power of amylase to coax a green banana into that starch-free, pure-sugar goo that is the essence of every deeply satisfying slice of home-baked banana bread. Well, there is, and it involves an egg yolk and no real skill beyond knowing how to separate an egg. 

Yolks are so rich in amylase that custard-makers must be cautious to wait until their creamy mixture is boiling to add them — lest they turn a potentially glorious dessert into a puddle of sweet goo, per The Free Library. But a puddle of sweet banana goo is exactly what home-baked banana bread needs. And it's what you'll get if you mash unripe bananas together with raw egg yolk — two yolks per eight ounces of fruit and wait about 30 minutes (via Serious Eats). Try it and see!