Bananas are usually harvested when green. In stores, you can usually find a range of colors from green to yellow, with brown spots. Your choice should be based on when you want to eat the banana: greener ones last more days, while yellow and brown-spotted bananas should be eaten in a few days.
Bananas should be quite firm, bright, and the peel should not be crushed or cut. Their stems and tips should be intact. The size of the banana does not affect its quality, so just choose the size that fits you best
Bananas are very fragile and should be stored in a place when they will be protected from concussions. They should be stored at room temperature to allow for the ripening process to complete. Do not store them in the refrigerator when they are green, or this will irreversibly interrupt the ripening process (and it will not revert even if they are kept at room temperature afterwards)
If you need to speed up the ripening process, you can place the banana in a paper wrap with an apple. While you should not keep green bananas in the fridge, it is actually a good idea to store ripe bananas there. Their peel will become progressively brown, but the pulp will not be affected. To improve the flavor, it is best to keep bananas at room temperature for a while
If you wish to store bananas for a long time (up to 2 months), it is possible to freeze them. To do this, simply remove the peel and sprinkle some lemon juice over the pulp to prevent discoloration; then wrap them in plastic