To help keep bananas fresh, store them at room temperature until they ripen. Refrigerate ripe bananas to keep them from ripening further. When bananas are frozen or refrigerated, the skin turns brown and black, but the fruit is still viable.
When freezing bananas, it is helpful to peel and then slice them into 1/2- or 3/4-inch pieces. Arrange the pieces of banana in a single layer on a baking sheet or plate to keep them from sticking together, and freeze for four hours. Next, transfer the bananas into a freezer-safe container. Bananas can be stored in the freezer for up to eight months. After eight months, they are still consumable, but the quality decreases.