How To Store Onions So They Last Longer

Onions are incredibly versatile. They can be pureed into soups, chopped up to add crunch to tacos or sandwiches, and add delicious flavor to just about anything. Because they can be used in so many dishes, it's a great idea to buy them in bulk. That means fewer trips to the store and potential savings at checkout.

Which brings us to another point: The other thing that makes onions a great candidate for buying in bulk is their long shelf life. When stored properly, onions can last weeks, even months.

So put that Costco membership to use, and stock up on onions—but first, make sure you know how to store them properly.

The Best Way To Store Onions

If you want to make sure your onions will last as long as possible, follow these tips.

1) Store onions in a well-ventilated place

The National Onion Association says it's imperative you store onions in a well-ventilated area. Otherwise, they'll mildew quickly.

If you buy your onions in a plastic bag, be sure to remove them as soon as you get home. A paper bag, basket, or cardboard box will provide better ventilation. Make sure they're stacked loosely so air will have a chance to circulate around them.

2) Store onions somewhere cool and dry

Whole onions will deteriorate faster if they're exposed to excess moisture. This means it isn't a good idea to store them in your refrigerator. According to the National Onion Association, the optimum storage temperature for onions is 45-55ºF. A basement, garage, or anywhere where they'll be protected from heat or sunlight will generally be the best fit.

3) Do not store onions with apples or potatoes

Potatoes release moisture, which will cause your onions to deteriorate more quickly. In addition, apples and potatoes are prone to absorb the pungent aroma of onions, so unless you want your apple pie to have a hint of onion, it's a good practice to make sure they are stored separately.

How To Store Cut Onions

Although you shouldn't store whole onions in the refrigerator, once you cut into an onion, you'll want to store the remainder in the refrigerator. Just make sure to place leftover onion pieces in an airtight container, like a plastic storage bag, or risk your entire fridge smelling of onion.

How To Freeze Onions

If you are looking for a longer storage solution for your onions, turn to the freezer. We don't recommend freezing whole onions, but chopped or sliced onions can be frozen (and will be ready to use straight out of the freezer).

Place your chopped or sliced onions in a freezer bag, and remove as much air from the bag as possible before freezing.

Freezing does slightly alter the texture of onions, so use frozen onions in cooked dishes like soups and stews, and avoid using them in raw applications, such as a topping for chili or hot dogs.

How Long Do Onions Last?

According to the National Onion Association, whole onions will last an average of one to three months if you store them properly. Cut onions on the other hand, only last one to two weeks. In the freezer, chopped onions can last about eight months.

How Can I Tell if Onions Are Bad?

If you're wondering whether your onions have gone bad, rely on visual cues. First, look for dark spots. This is usually a precursor to mold and a good sign your onion is starting to turn.

A good onion should be firm to the touch. If you feel soft spots, the onion is past its prime.

If your onion has started to grow sprouts, that is also an indication it has gone bad. Lastly, give it a good sniff. If it smells "off" then it's probably a good idea to dispose of it and reach for a fresh one instead.