Can You Save Leftover Mashed Banana (And If So How Long)?

It can be almost as tricky to pinpoint when a banana is perfectly ripe as it is with avocados, which can lead to frustration when you have a bowl of overripe fruit in your kitchen. However, by peeling, mashing, and refrigerating or freezing bananas at peak ripeness, you can make sure you always have some on hand for fruit smoothies or other sweet and savory banana recipes, no matter what stage they're in at your local grocery store.

What you see is what you get with this fruit. Green bananas won't get any sweeter after they're mashed, so wait until their peels turn yellow. A few brown spots are okay, but you don't want them overripe since the flesh inside can also turn brown and mushy.  After peeling, use a fork or potato masher to break up the chunks and smooth them out. Then add a teaspoon of lemon juice for every cup of banana to keep them from oxidizing and turning brown before you're ready to use them.

If you plan to use mashed bananas soon, keep them in your refrigerator. Spoon the mix into a glass or plastic container with a tight lid, pressing down to get rid of any air bubbles that can encourage oxidation. They can last up to seven days in the fridge, helping you plan out a week of breakfasts or extend the use-by date of your fruit until you have a chance to bake bread. But if there's any whiff of fermentation with a slightly alcoholic or unpleasant smell, then it's time to dispose of them.

For longer-term storage, freeze your mashed bananas instead. After peeling, mashing, and stirring in the lemon juice, spoon the mixture into freezer-safe bags, ice-cube trays, or other containers, measuring out the typical amounts you use in your recipes. Leave a little room for the bananas to expand as they freeze, and squeeze out as much air as you can before sealing. They should stay at their peak for two to three months, though they'll still be safe to use after that time as long as they remain frozen. 

If you're saving your fruit for smoothies, don't be tempted to just toss the whole banana in the freezer, since frozen chunks of that size can be hard on your blender blades. The mashed ones are easier to manage. Just thaw them overnight in the fridge or pop them into the microwave, and they'll be ready to enjoy in no time.