How To Make A Banana Ripen Faster. Place the unpeeled bananas on a lined baking sheet. Alternatively, put your bananas in the freezer for a few hours.
The basic principle is to trap this ethylene gas as much as possible to ripen bananas faster. Place the bananas in a paper bag with an apple or an already ripe banana. Cover the baking sheet with parchment paper to catch leaks from the mushy bananas.
The basic oven-ripening trick goes like this: Place your bananas, still in their peels, on a lined, rimmed baking sheet (because they ooze, sometimes).
This prevents them from getting bruised and becoming exposed to air.
Try speed-ripening bananas in the oven. Loosely fold the top of the bag down and place it on the counter or in a closet. Oven: Put unpeeled bananas on a foil-lined baking sheet.