“I wish this banana was badly bruised and mushy,” said no one, ever. Well, unless they’re trying to bake with bananas. Whenever you need overripe bananas, you don’t have them. You can, however, speed up—and fake—the natural ripening process. Keeping the bananas together in a bunch instead of separating them, and placing them somewhere warm (on top of the fridge or near a heater, for example) means they’ll ripen faster. But for swift mushy-banana results, use these tricks:
Paper bag method (kind of fast) If you don’t need your baking bananas that day, place them in a paper bag and close it. Wait at least 12 hours. Bananas give off ethylene gas as they ripen; trapping the gas in the bag encourages them to ripen more quickly.
Oven method (faster) Set unpeeled bananas in the oven at 300℉ until they turn black, 15 to 30 minutes. Use a rimmed baking sheet. The bananas will probably leak.
Microwave (fastest) Deeply pierce the skin of the bananas in several places and on all sides with a fork. (Make sure you go all the way through the skin.) Microwave on high at 30 second intervals, checking for softness as you go.
Don’t try these tricks with green bananas; they won’t work. And keep in mind that artificially ripening bananas means that some of the starch won’t be converted into sugars, so you may not get the same flavour as you would with bananas that slowly ripened naturally. But hey, small price to pay: sometimes you just want banana bread. And you want it yesterday.