It depends on the state you bought them in and the way you like them. In your grocery store you may find bananas that are green-tipped, full yellow, or yellow with brown spots. All of these bananas are ready to eat. Bananas with a yellower skin color have a sweeter flavor. Bananas are fully ripened when brown spots appear on the peel. These bananas have a softer texture and are very sweet. The further ripen bananas. take them out of the plastic produce bag and store them at room temperature. The bananas will continue to ripen. Storing bananas on a banana hanger or hook is the best way to preserve the overall quality of a ripe banana as it avoids "resting bruises." Store bananas away from doors, windows, exterior walls, and cold or hot drafts. If your bananas are too green, you can put them in a paper bag to ripen. If you add an apple or tomato to the bag, the bananas will ripen even faster. Now, back to the question. When the bananas get to the desired ripeness, just put them into your refrigerator. The skin turns black, but the banana inside stays perfect for two or three days. Never store unripe bananas in the refrigerator! They simply will not ripen properly because the cold interferes with the ripening process. I read somewhere the best way for storing bananas is to peel them, put them in a plastic box as a whole and refrigerate them, and they'll keep well for more than 2 weeks, losing none of their taste or texture. I can 't confirm this though, haven't tried it yet. You can also peel bananas, cut them in chunks, freeze them and eat them as a frozen treat, reminiscent of ice cream. You can also take those frozen chunks and make a very creamy smoothie using fat free rice milk or soymilk and a little flavoring.

I heard that ripe / even rotting apple and tomato emit the gas that cause the ripening effect.

Best Way to Keep Bananas Fresh From: http://www.ehow.com/how_4547883_best-way-keep-bananas-fresh.html Step 1 Use proper storage techniques. The best thing to do for bananas is to keep them out in room temperature, away from high heat or direct sunlight, in a fruit bowl or on a banana hanger. Bananas will stay fresh for at least a week this way. If you have eaten only part of the banana and want to keep the rest, wrap the open end back up in its skin and seal it in a plastic bag. You can store it in the refrigerator and it will keep for several more days. Step 2 Speed up the ripening process. Since everyone has a different opinion on when a banana is "ripe" and tasty there are things you can do to speed the ripening process. If you bought green bananas from the store and would like them to ripen sooner, place the bananas in a paper bag for 2 to 3 days. This will speed up the ripening process. The skin may still appear green but the flesh of the fruit will be soft and sweet. Step 3 Store in the refrigerator. Once a banana has reached its peak of ripeness, you can also keep them that way by putting them in the refrigerator. The skin may turn dark brown, but the fruit itself will remain ripe and sweet for 3 days longer. Step 4 Freeze for baking. If you find your bananas have ripened and you will not be able to use them at their peak, take them as they are and throw them in the freezer. The flesh will turn brown/black, but the banana will retain its sweet flavor. Bananas stored like this are best for cooking and baking once they thaw out, as they will be mushy.

in a fruit bowl........duhhhhh

I haven't found an acceptable way to store them more than a couple of day. I like them just as the green disappears so I don't buy more than I will eat within a couple of days.

They have those neet little bag's now .. put them in there and put them in the frig... Last about two weeks.