Bananas are always picked and shipped green so they won't rot before they arrive at the grocery store. Green bananas are more resistant to bruising because the fruit is mostly starch, which is more stable than sugar. They do not, however, have that mellow yellow banana flavor. A fully ripe banana has a deep yellow skin speckled with brown flecks. As the banana continues to ripen the skin turns darker and eventually becomes black.
It's a snap to get green bananas to go yellow in a few days. You can simply wait for the process to happen on its own, or you can speed it up using a brown bag. If you need a banana fix right away, you can even ripen your fruit in the oven.
Hang the bananas in an open mesh basket so the air can circulate around them. If you place bananas in a bowl, the moisture is trapped between the bowl and the banana peel, which may devlope mold. Another option is to leave bananas on a wood board or counter.
Wait a few days. The bananas will start to lose their green color and start to turn yellow. They'll soften and smell more like bananas as well.
Peel a test banana. The peel should easily come away from the banana inside.
Brown Bag It
Fold the bag down as close to the bananas as possible. Bananas and other fruits give off a gas called ethylene. The presence of the gas encourages fruit to ripen. Putting the bananas in the bag concentrates the gas so the bananas ripen in a few days.
Check the bag every day by unrolling it and looking at the color of the banana peel. When it's golden yellow, the banana is ripe.
Preheat your oven to 350 degrees Fahrenheit.
Line a cookie sheet with tin foil and place the bananas on it, peel and all.
Bake your bananas for 25 minutes.
Allow the bananas to cool thoroughly. Once cooled, the bananas are ready to peel and use.