Onions come in different varieties and shapes. They can be yellow, white, or red onions. They also come in bulb forms or in shoot form like scallions. But do onions go bad? How do the two types differ?

Quick Answer

Onions last longer than many vegetables, but they can spoil quickly if not stored properly. Whole onions have a shelf life of 4-6 months if kept out, or 1-2 days if chopped or sliced. Freezing chopped onions will keep them fresh for 6-8 months. Whole onions have layers and a paper-like shell that protects it from moisture. Cut onions spoil faster due to being exposed to moisture once their shell has been punctured or removed.

Like most fruits and vegetables, moisture is the enemy of onions. Depending on how well you protect against moisture determines how long onions can last.

Do Onions Go Bad? How Long Do Onions Last?

An onion has added protection from the elements due to its surface and layers, but they will spoil if not protected from moisture and heat.

How Long Can Onions Be Left Out?

Whole: Whole onions can last between 4-6 weeks if kept away from moisture in a relatively cool temperature. Onions are made up of layers that protect the vegetable from moisture and thus can be kept out for longer than other vegetables.

Chopped / sliced: Cut onions are a different story. If left out, they won’t last more than 1-2 days before beginning to spoil.  Without its protective outer skin, chopped or sliced onions are exposed to moisture.

Scallions: Scallions may last up to 2 days on the counter. Scallions also share a similar counter life due being made up of water.

How Long Do Onions Last In The Fridge?

Whole: Raw onions last about 1-2 months in the fridge. Onions are one of those interesting vegetables that don’t necessarily last longer in the fridge. In a refrigerator, the cold temperature converts the starch present in onions into sugar. The starch is what keeps onions firm, so breaking down the starch softens onions.

Chopped / sliced: Chopped or sliced onions will last from 5-7 days when stored in the fridge. The refrigerator is chopped onion’s friend when it comes to keeping it fresh.

Scallions: Scallions will last about 1-2 weeks in the fridge, similar to chopped onions. This is in part to the water content present in scallions.

How Long Do Onions Last In The Freezer?

Whole: It is not advised to freeze whole onions, due to their freezer space and prepping them to them beforehand. Whole onions must be blanched, boiled in water for 7 minutes if put in the freezer.

Chopped / Sliced: They can last from 6-8 months if kept in an airtight container or freezer bag.

The freezer works wonders for chopped or sliced onions. 

Scallions: Scallions also benefit from freezers, having a shelf life of 6-8 months. It is best to chop them prior and freezing in bulk for ease of use.

Onions last relatively longer than other vegetables. With whole onions, cool and dry areas are best. Airtight containers work best for chopped or sliced onions.

What Are The Signs Of A Rotten Onion?

There are several signs that can reveal whether an onion has turned rotten.

 Color: Check the onion for any discoloration. If you see any brown or black spots, then the onion has started to spoil.

Texture: Feel for soft spots. A fresh onion should be firm with no soft spots anywhere. When the whole onion becomes squishy or moist, the onion is spoiled and should be discarded.

Layers: With any onion, it’s normal to peel off a few of the outer layers that may have lost their firmness. If you find that you have to remove several layers, say more than 4, then it’s a sign that the onion is old and should be tossed.

Mold: Black streaks of mold may appear on the surface of the onion. This is normal and can be washed off and stored in the fridge. Take care to not have the onion make contact with any other vegetable.

White Liquid: If there is a discharge of a white or creamy liquid, this is normal. The liquids are stored water being released. Check to make sure the onion is still firm.

How Should Onions Be Stored?

Whole: Raw onions will last longer if kept in a cool, dry place. The best place to store them would be in the pantry, away from the sink or oven.

Chopped / Sliced: Keep onions in an airtight container or bag. Depending on quantity and use, you can store them in the fridge or freezer. Opt for the fridge if you plan on using them for meals within a week. Choose the freezer if you have a large quantity of onion and plan on using them later.

Scallions: Scallions are best left in the fridge in an airtight container or sealed bag.

Is Freezing A Good Choice For Onions?

Yes, freezing is an excellent choice for chopped or sliced onions and scallions. They will last for quite a while, up to 8 months, if kept in an airtight container or freezer bag. They are not an ideal option for whole onions as they need to be blanched before freezing. Also, because of their size, they take up valuable space in the freezer.

Frequently Asked Questions About Onion’s Shelf Life

My onion has green sprouts growing out of it. Is it safe to eat? Yes, the onion is still safe to eat. The sprouts are not a sign of spoiling and are edible. Remove the shoots from the onion, cut the onion in half, and remove any remaining sprouts. Remember to check for firmness as a sprouting onion may indicate it is close to spoiling.

Can I Freeze Whole Onions? It is not recommended to store whole onions, but it is possible to do so. To freeze a whole onion, they must be blanched before placing in the freezer. To blanch an onion, place in boiling for 7 minutes and immediately after, place in ice water.

What’s the best way to store onions at room temperature? Place them in a mesh bag or paper bag with holes to let the onions breathe. An old pantyhose is another option that can be used. Any bag that isn’t sealed can suffice. Make sure onions are unpeeled and intact. Any perforation into the surface will allow moisture to enter and accelerate spoiling.

Wrap Up

Taking care of onions will not only prolong their shelf life, but allow you to create tastier dishes for longer periods of time. Whether you’re freezing them or leaving them in the fridge, always check their texture and taste for spoiling.