As bananas ripen and develop black spots, their flavor becomes much sweeter, the peel thinner, and the pulp softer. It can take more than a week to reach this point. If you don’t have time to wait for the bananas to ripen naturally, an alternative method of “ripening” is to freeze bananas in the peel overnight. They can be defrosted in less than 30 minutes in a room temperature water bath, then slit lengthwise and the pulp removed. Ripening bananas naturally, however, produces a sweeter flavor. Any extra banana pulp can be frozen for several months.