Onions are a staple food used since prehistoric times, and it’s worth stocking up on them if you cook often. The question is, how long does an onion last, and how should we store onions so they stay fresh for as long as possible?
Onions are used in most cuisines around the world and not sparingly either. An impressive number of recipes are flavored by this common ingredient which has a pretty long shelf life if stored properly.
On that note, it’s good to know how long onions last in different storage conditions. This way, you can choose the best one for you and avoid buying too many only to see them going bad.
🧅 How Long Can You Keep Them Out?
Whole raw onions last for 2-3 months if stored in a cool, dark place, at temperatures between 45°F-55°F.
Not everyone has a space with these conditions in the house. For some, a cellar, an unheated basement, a garage, or a cool pantry might offer the solution.
If you don’t have any of the above, the fridge is the best option. Whole raw onions will last at least 2-3 months in the fridge.
Not enough fridge space? Onions stored at room temperature last for 2-4 weeks. You will simply need to make sure you don’t buy more than you can consume within this time frame.
Sweet onions are an exception. They have a shorter shelf life compared to yellow, red, and other varieties, because of their lower pyruvic acid content.
Sweet onions last for 1-2 months in the fridge or a pantry with temperatures between 45°F-55°F. At room temperature, they will last for about 1 week. I like keeping mine in the fridge since it gives me more time to use them.
Also, raw green onions (scallions) last for 1-2 weeks in the fridge, stored in a plastic bag in the crisper drawer. It’s worth keeping them in the refrigerator since they only last for about 3 days at room temperature.
🔪 How Long Does A Peeled Or Cut Onion Last?
Onions that have been peeled, halved, sliced, or chopped are best stored in the fridge.
The best way to store them is in a ziplock bag, an airtight container, or wrapped tightly in plastic wrap or aluminum foil. When stored like this, they last 7-10 days.
Cooked onions should be stored in the fridge the same way, and they stay safe to eat for 3-5 days like most cooked foods.
❄️ How Long Do They Last In The Freezer?
Raw onions can be frozen for up to 8 months and cooked onions will last up to 12 months in the freezer.
Whole frozen onions can take up a lot of space which is why it’s best to freeze them sliced or chopped.
🍱 How To Store Them So They Stay Fresh For Longer
Extreme temperatures and humidity are the main factors that can cause onions to spoil faster.
In The Pantry
To keep moisture away from onions, store them in a way that allows the air to circulate around them.
Keep them uncovered in a mesh bag, basket, bin, or a large bowl away from the sun. If you purchased them in a plastic bag, I definitely recommend you take them out and place them in an appropriate container.
Otherwise, moisture will cause them to sprout or encourage mold to develop.
In The Fridge
It’s not ideal to store whole raw onions in the fridge as they can easily absorb moisture and soften. Without a room or a place that’s cool enough, the refrigerator is still a good option!
Ideally, you should store them in a perforated bin that allows air circulation, away from moist foods.
On the other hand, raw, cut onions and cooked onions should definitely be stored in the fridge. Keep them in an airtight container, ziplock bag or tightly wrapped in plastic wrap or aluminum foil.
Note: Whether you like to keep them in the pantry or the fridge, don’t store onions and potatoes together! The ethylene gas produced by onions causes potatoes to ripen faster. Also, potatoes release moisture that can soften onions and turn them into liquid mush.
🧊 Best Freezer Tips
Freezing them is possible and even more, it keeps them safe to eat for a long time.
You have as long as 8 months to use frozen raw onions and up to 1 year if they’re cooked.
I always slice or chop before freezing them so they take up as little space as possible. This is excellent for meal prepping!
Freeze your raw onions in an airtight container, freezer bag, or wrapped in aluminum foil or plastic wrap. Cooked onions are best frozen in an airtight container or freezer bag.
🛑 How To Tell If They Have Gone Bad
Some signs of spoilage are obvious, while others can be misleading. Here’s what to look out for if you suspect your onions have gone bad:
- Off or unusual smell – Rotting often develop a strong, sharp smell. In contrast, whole uncut onions have a very subtle earthy scent. If they smell unusual in any way, it’s best to discard them.
- Soft or slimy – Fresh onions are firm to the touch. If yours feel soft, mushy, or slimy that’s a sure sign they’ve gone bad. If only a small area is affected you can get away with cutting the soft part or peeling the affected layers.
- Visible moldy or rotten areas – If you find a small spot that’s black, brown, or another color it’s usually okay to remove it and use the rest of the onion. Anything larger than that means it’s no longer safe to eat.
- Discolorations – Does your peeled onion look discolored? It’s probably gone bad. In this stage, it probably doesn’t smell good either.
Keep in mind the outer layer of an unpeeled onion always has a papery texture and has to be removed. In some cases, the first few layers can be dirty, coarse, and dry. Once you remove those, the rest of the onion is perfectly safe to eat and cook with.
Another thing you might come across is a brown dry layer inside the bulb. If that happens, cut the onion in half, take it apart, and remove the layer. Then, you can use the rest.
As long as you don’t notice any of the spoilage signs above, a sprouting onion is safe to eat. You’ll need to cut off the sprout and the green part it grows from inside the bulb, but the rest of the onion is usable.
Whole, raw onions last for 2-4 weeks, when stored at room temperature. Sweet onions make an exception as they contain lower quantities of pyruvic acid content, compared to most other varieties. They only last for about 1 week on the counter.
You can keep them in the fridge or a pantry with temperatures between 45°F-55°F which makes them last for 1-2 months.
Technically, yes, although you might have seen conflicting opinions on the topic. The USDA doesn’t recommend storing onions in the fridge because the low temperatures convert the sugar they naturally contain into starch. This will cause them to absorb moisture and become soggy.
In reality, the refrigerator is the only option for many people. If you don’t have a cool area in your home with temperatures between 45°F-55°F, and you live in a hot climate, the fridge is the best place to store your onions.
Make sure you keep them in the lower part of the fridge, ideally, in a perforated bin to encourage air circulation.
A common fungus in the soil called Aspergillus niger causes black mold on onions. If you remove the affected layers or cut off the affected area with some margin, the rest of the onion can be used.
As an exception, people allergic to Aspergillus niger should not use onions with black mold, even if the affected area was removed.
No, unpeeled raw onions shouldn’t be washed regardless if you store them in a pantry, or the fridge. Moisture causes onions to soften and eventually rot very fast.
They are best stored in a cool, dry, and dark place.
This layered veggie adds a touch of magic to many dishes and if you’re like me, you always have some in your pantry.
If you’re having with a surplus don’t forget it’s always great in a salad. Even if it’s a simple one with limited ingredients like my tomato, cucumber, and onion salad.
Sliced or diced onions are great as a topping in tacos, hamburgers, and sauces. And if you want to enjoy the amazing taste of onion in all its layered beauty, you have to try the Air Fryer blooming onion.
Knowing the shelf life of onions is the easiest way to make sure you never buy more than you can use.
By now, you’re hopefully no longer wondering how long does an onion last, or how to store it properly. Long-term, this will save you money and help you avoid waste at the same time.