Can Frozen Bananas Make You Sick?
If you’re like me, bananas are a staple ingredient in your household. They’re a good source of fibre, loaded with essential nutrients, and are a great “on the go” snack. They also tend to get overripe faster than I can eat them (thank you Costco for selling them in such large bunches). Which is why I’ve taken to tossing them in the freezer just before this happens. But how long is too long, and is it possible for frozen bananas to make you sick?
Whether you freeze bananas unpeeled or pre-sliced, as long they are stored at a constant temperature of 0 °F (-17.8 °C), frozen bananas will always be safe to eat. That said, the quality of frozen food does get impacted by longer storage times. However frozen bananas will stay fresh without losing their quality for between 2-3 months.
So in general, freezing bananas won’t make you sick. But there is still one exception to be aware of. Let’s take a closer look at what that exception is, as well as how we can maximize the flavour you get from your frozen stash of tropical goodness.
How Do You Freeze Bananas?
You might decide to freeze a perfectly good banana if you realize that you’re not going to be able to eat it in time, before it starts getting overripe.
How do you tell if you have a ripe banana? Well, the most surefire way is eating it and seeing if you have that yucky film on your teeth after the first bite. But that defeats the purpose of storing it!
A great way to visually tell if you have a ripe banana is when it has no green on the skin, has some brown spots, and feels soft when you give it a light squeeze.
In these situations, freezing a ripe banana is an excellent move. According to FoodSafety.gov, bananas will retain their freshness and quality for 2-3 months if frozen from the date of purchase. This means once you thaw that fruit, whether you need it as an ingredient for a recipe, or simply want a healthy snack, it will taste as good as the day you decided to freeze it.
Generally most of us aren’t fans of overripe, squishy fruit. However, there are instances where it’s not only ok, but desirable. Banana bread and muffins are excellent examples of recipes benefiting from this. In fact, the darker the banana, the more flavour it brings to your baking. That’s because the starch in the flesh converts to sugar, resulting in a sweeter fruit!
Determining whether your bananas are overripe is pretty straightforward: it will usually have plenty of brown and even black spots covering much of the surface of the skin. As far as texture, it will feel very soft, almost squishy to the touch.
What is the best method to freeze bananas?
Depending on how you intend to use your bananas, the easiest method is to stick them whole and unpeeled in the freezer. The banana skin acts as its own container, and saves you from having to use a ziplock bag. This is typically the best approach if you want to use your bananas in recipes such as banana bread. When it’s ready to be used, simply defrost by leaving on the kitchen counter and bring to room temperature.
Another option that is great for snacks for the wee ones, is to freeze them mashed. First unpeel them, mash with a fork, and then stick in a ziplock or vacuum sealed bag. If you’re doing this, try to squeeze out as much air from the bag as possible. This will greatly extend the freshness and quality of your food.
My personal favourite method for storing frozen bananas is to first slice a peeled banana into smaller pieces. Then lay them individually on a parchment-lined baking sheet, and stick the sheet in the freezer for a couple hours. Once the slices are frozen, transfer them to a ziplock, press the air out and toss them back in the freezer. This method prevents individual slices from getting frozen stuck together, which is a royal pain when I only need to grab a few slices to toss into my favourite smoothie of the month.
How Do I Know If My Frozen Bananas Are Bad?
There are a couple ways to visually identify whether the bananas that you purchased have gone bad. The first is mold. Mold on bananas looks like a fuzzy white felt, and typically starts forming at the tip of the fruit (opposite the stem-side). The second cue is slimy liquid forming beneath your resting fruit. Both are key indicators that your fruit is starting to rot, and is no longer safe to eat.
If you happened to miss these signs, and chucked those spoiled bananas in the freezer, the act of freezing will inactivate the mold microbes. However, as soon as you thaw the fruit, those same microbes will become reactivated. This ends up posing the same risk as before of making you sick. Freezing will not kill those harmful microorganisms.
If this situation might apply to you, worry not! Your frozen bananas can remain in the freezer until you’re ready to use them. When that time comes, defrost them and then carefully inspect for any traces of white mold. If there is any fuzzy formation to be seen, chuck it.
How Long Do Frozen Bananas Last?
Whether its ripe or overripe at the time you freeze it, if your banana was non-moldy to begin with, it will always be safe to eat. Freezing allows food to be stored for extended periods of time because it prevents growth of the microorganisms that cause food to become spoiled.
That said, while your bananas can be frozen indefinitely without worrying about spoilage, there is another thing to consider, and that is taste. If you want your frozen bananas to taste the same as if they were fresh, try to eat them within 2-3 months of freezing.
The USDA recommends freezing food at peak quality, as the food ends up tasting better when thawed, compared to foods frozen at the tail end of their shelf life. While we agree that this generally applies to most food items, bananas are one of the few exceptions. For recipes such as banana bread, it’s actually more beneficial to let the banana get a bit overripe before throwing them in the freezer. That’s because as we covered earlier in the article, the ripening process allows the banana to get sweeter.
Can Thawed Bananas Go Bad?
If freezing bananas protects them from potentially harmful microbes, thawing them reintroduces that risk.
Thawed bananas are just as susceptible to going spoiled as any other produce that is left at room temperature for extended periods of time. That’s why, if you’re not planning on using your bananas that same day, transfer them from the freezer to the fridge, and let them defrost overnight. Compared to your kitchen counter, the fridge’s cooler environment will help slow down the food’s aging process and prolong the life of your produce.
Let’s say you made an oopsie and left that thawing banana on the counter for a couple nights. Because it’s already gone through the freeze/thaw cycle, it can sometimes be tricky to visually determine whether or not it’s spoiled.
Generally when it comes to the risk of potentially eating food that’s been spoiled, I recommend erring on the side of caution and throwing it away. However, if you’d like to give that banana a fair chance, we recommend doing the smell test: if it smells musty or overly fermented, chuck it.
Why Did My Frozen Bananas Turn Brown?
It’s common for the flesh of many fruits such as bananas to turn brown when exposed to air. This process is commonly known as oxidation. Apples and avocados are examples of other fruits that will brown over time once they’re cut open. While freezing pre-sliced bananas slows down this oxidation process dramatically, it does still occur.
It’s important to note that while your frozen banana slices will start to turn an unappealing brown color over time, that’s fine! The oxidation process is harmless and does not impact the nutrient quality of your produce. No matter how brown it gets, your frozen goodies are perfectly safe to eat when you’re ready for them.
If you’re someone that eats with your eyes before your mouth, there is one handy trick you can consider to stop your bananas from browning. Before freezing your slices, squeeze a little lemon juice over them. The acid from the citrus fruit will inactivate the enzymes that cause browning to occur. I like to use this method for the bananas that end up in my smoothie shakes. The extra flavour from the lemon juice adds a nice bit of zing.
Why Do Bananas Turn Black When Frozen?
When it comes to whole bananas, if you freeze them you’ll find that the skin rapidly changes color, turning brown then black. This process also occurs when you refrigerate them, but is accelerated when you throw them in the freezer. Why is that?
Bananas turn black when they’re frozen because the water content that is present in the fruit transforms into ice crystals. These ice crystals expand and cause cells in the banana skin to rupture. The rupturing of those cells releases polyphenols, which speed up the blackening process.
As with the pre-sliced banana slices, a change in color is nothing to be concerned about, and your whole banana remains perfectly safe to eat.
When it comes to freezing whole bananas versus pre-sliced, one noticeable difference is their post-thaw state. Compared to pre-sliced pieces, you’ll find that whole thawed bananas are mushy. The thawed banana is mushy because when it was stored in the freezer, ice crystals formed and expanded, breaking cell walls within the banana. As it defrosts, the ice crystals turn back to water, and those broken cell walls collapse, leaving you with a liquidy, mushy end product.
That mushy goodness is perfect for baking. When you cut open your defrosted banana, make sure you’re also including the accompanying liquid in your recipe! That sweet, liquid goodness is a big part of the flavour that goes into your banana bread or muffins.