When you’ve already planned out a meal to make, the last things you want to find when you go into your pantry are rotten vegetables.
But with some vegetables, it’s harder to tell when they’re nearing the end of their shelf life. Onions are one such vegetable.
When asking the question, “How long do onions last?” there are a few factors that need to be taken into consideration.
It’s not as simple as one timeframe, mainly because onions are often stored in various forms. Each of these forms—whether whole, cooked, or otherwise—have different storage requirements and different shelf lives.
So, how long do onions last? Let’s go over what you need to know!
The Best Way to Store Onions
The most important thing to keep in mind—at least, with whole onions—is to avoid exposing them to moisture as much as possible.
That means no fridges, if you can help it.
Heat is also a no-go for onion storage. You can extend the shelf life of onions by keeping them in the driest and darkest place you can.
Usually, your pantry is the way to go for whole onions. There’s a few reasons why…and also many other ways to store onions, both whole and used. Make sure you study up in order to extend the shelf life of onions as long as you possibly can!
How Long Do Onions Last?
So, in general, how long do onions last?
The answer to this question varies considerably based on whether the onion is whole, peeled, cut, or cooked. It also depends on how they’re stored.
When it comes to the shelf life of onions kept whole, you’re in luck! Whole onions last quite a long span compared to other less hearty vegetables.
Whole onions, when kept in dry, dark, cool place, will last up to 90 days.
You can store onions in your pantry, your basement (only if unfinished/unheated!), or even your garage (though not in the summer!) to extend the shelf life of onions as far as you can.
A peeled onion, however, should be kept in the fridge, as should onions cut or cooked in any way.
The shelf life of onions that are peeled is about two weeks in the fridge; they’ll last longer in the freezer. In the fridge, cut onions will last a little over a week; if stored in the freezer, they can be used in your recipes for up to six months.
The shelf life of onions already cooked is the shortest; they won’t quite make it a week. You’ll want to throw out your cooked onion leftovers after about four or five days.
In general, your fresh onions will last the longest so long as they remain whole. If they’re cut or peeled, they’ll last the longest in the freezer, but they may not taste as fresh upon thawing.
This also eats up a lot of space in your freezer. If you plan on freezing a large number of onions at once—for instance, if you’re growing your own crop—you may want to invest in a chest freezer.
Freezing onions takes considerable care, and the method is different for peeled or chopped onions. Make sure you research the best way to freeze your onions.
What to Do With Onions About to Go Bad
When you start to get close to the end of the shelf life of onions, don’t panic—there are plenty of ways to use them up!
One option, of course, is to freeze your remaining onions. Just make sure you use these onions in your next recipe first before using any new onions you buy!
Otherwise, you could end up in a cycle of constantly storing onions in your freezer and never using them up.
One helpful way to keep track of your onion stock is by utilizing a magnetic dry erase list on your fridge.
You can use these lists to keep track of what you have in your fridge and freezer. You can also keep track of expiration dates, which will let you know when your frozen onions are unable to be used anymore.
It can be easy to lose onions and other frozen veggies in the back of your freezer. By keeping a list, you’ll be able to avoid running into an out-of-sight, out-of-mind situation!
If you don’t want to freeze your onions, or only have one or two you need to use up, there are plenty of recipes you can make instead!
You can take advantage of fresh onions by cooking recipes that won’t come out as well with thawed frozen onions.
For instance, you can make tomato salsa, onion rings, or roasted onions. (Yes, you can roast onions and serve them as their own dish!)
Otherwise, you can freeze your raw onions in preparation for future thawing for recipes. You can even start the process by caramelizing your onions or sautéing them beforehand and freezing them afterward!
How To Tell When Onions Have Gone Bad
One way to answer the question “How long do onions last?” Well…if you pick up an onion and examine it, you’ll have a definitive answer.
Onions that are past their prime will begin to grow sprouts, similar to the way a potato sprouts when it’s aged.
You also may notice mottled spots or patches of mold on aging onions. If the shelf life of onions is close to expiring, you might also be able to feel soft areas on your onion.
If your onion is no longer firm to the touch, it’s probably best to get rid of it. Don’t ever cook with onions that have sprouted or are going moldy.
Even if you cut the moldy patches off, that doesn’t mean they’re safe to eat.
Also keep an eye out for any sort of slick, slimy spots on your onion. As mentioned, avoiding moisture is key to keeping your onions good. They will not express moisture like that without having gone bad.
What to Do With Old Onions
If you’re on your way to the trash can with your bag of old onions, hold your horses! There’s still plenty you can do with them before you send them off to the dump.
Namely, you can add them to your compost bin.
If you aren’t familiar with compost bins, they’re various kinds of containers used to create homemade compost. You can spread compost in your home gardens and other landscaping areas to improve the health of your plants.
Compost bins can include the clippings from mowing your lawn, old leaves (no more bags on the curb!), manure, and…wait for it…old vegetables!
Vegetables and fruit don’t have to go in your trash. Instead, even if they’re past the point of beginning the rotting process, you can throw them right in your compost bin.
There are some people out there who claim that you can’t put onions in your compost bins for various reasons. This isn’t true.
You can throw whole onions in your compost mixture, even if they’re well on the way to worm food. In fact, if you have a “worm bin” as your compost bin, that might be exactly what they’re meant for!
The only thing to keep in mind before adding onions to a worm bin is that you should test it first. With strong-smelling, acid-heavy things like onions and garlic, you want to test a small amount to make sure it doesn’t harm your worms.
Worms absorb oxygen through their skin. Because of this extra-absorbency, anything in their surroundings with acidic or otherwise noxious properties can cause problems.
Also, worms might just not like to eat your onions. (Yes, worms can be picky eaters, too!)
Check back to see if your onion scraps have been eaten through, or if they’re being avoided.
If your compost bin isn’t a worm bin—that is, you didn’t add worms yourself—you can add onions and garlic without concern. While it might worsen the smell of your compost, it will also keep bothersome pests away.
Compost bins can become a haven for annoying visitors like gnats and other animals that might try to pick at your scraps. Onions and garlic can act as a natural pest repellant in your bin.
Compost is a great way to repurpose your old onions and create free and environmentally friendly fertilizer for your garden!
Keep an Eye on Your Onions!
So, how long do onions last? At the shortest, the shelf life of onions is four days; at the longest, six months. It all depends on whether they’re whole or not, where you store them, and what you store them in!
To find out more about onions, including growing, storing, and more, visit our onion page now!