Have You Been Storing Your Onions Wrong All Along? Food Experts Clear Up the Confusion
Plus, here's how to tell if your alliums are past their prime.
Onions are seriously one of the most useful ingredients to have stocked in your kitchen. They can enhance the flavor of everything from soups to sauces and beyond. But as with every fresh ingredient, onions don’t last forever and can go bad quickly if you don’t store them properly.
The good news? You can keep your onions fresher longer by following a few key storage tips. Keep reading for advice on how to store onions from culinary pros.
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How Long Do Onions Last?
First things first: How long do onions last, really? “Depending on the storage conditions, whole raw onions can maintain their quality between three to six months,” says Melanie Marcus, RD, a culinary dietitian from the greater Charlotte, North Carolina area. On the other hand, cooked onions typically last three to four days in the fridge when stored properly, she adds.
How to Store Whole Onions
How to store onions depends on what type of onions you have. Got a bunch of whole raw onions? Elizabeth Shaw, RDN, president of Shaw Simple Swaps, suggests following the advice put out by the National Onion Association: “These growers recommend storing them in a cool, dry and well-ventilated environment like a pantry or cellar, ideally with an average temperature of 45 to 55 degrees Fahrenheit,” she says. “They also recommend avoiding placing the onions in a bag or with other produce that releases moisture as both these practices will reduce their shelf life.”
According to the National Onion Association, when stored properly like this, whole onions can last up to 180 days in the fall and winter months and up to 60 days in the spring and summer months.
Marcus suggests placing whole onions in a mesh bag or wire basket (not plastic) for best results. And don’t refrigerate whole onions with the peel either because “this allows for moisture from the fridge to settle into the paper layers and accelerate decomposition,” she explains. “If you must store them in the refrigerator to keep them cool, then wrap them individually in newspaper or paper towels to keep them dry.”
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How to Store Cut Onions
Now you know how to store whole onions—but what about peeled, cut onions? If you’re wondering how to store cut onions, here’s a good tip: “Peeled and cut onions should be stored in an airtight container in the refrigerator for seven days,” says Marcus. Shaw adds that you should make sure your refrigerator is set to 40 degrees Fahrenheit or below when storing cut onions.
How to Store Green Onions
Green onions make a great garnish for dishes like pasta, soup and salads, but if you’re curious about how to store green onions, Shaw recommends them in the fridge at under 40 degrees Fahrenheit for best quality. “I personally like to discard any outer parts that appear a little past their prime, then rinse the green onion under cool water, pat dry and wrap in paper towels to store in the refrigerator’s produce drawer for easy use throughout the week,” she says.
Marcus, meanwhile, shares this advice: “Treat green onions the same way you would fresh herbs,” she says. “Place the root end in a glass of shallow water then cover with a plastic bag to keep humidity in. You can also store them in the fridge in a zip-top bag with a damp paper towel to help maintain moisture.”
How to Store Potatoes and Onions
Wondering how to store potatoes and onions? Well, we hate to be the bearers of bad news, but you don’t want to store them together. “You should not store onions with potatoes or other vegetables since they do contain moisture and may cause the onions to go rancid quicker,” says Shaw.
Marcus says that onions emit ethylene gas that will make potatoes ripen quickly, while potatoes have a high moisture content that will make onions go bad when stored close together. “They both benefit from plenty of space and airflow during storage to prevent spoiling,” she says. “Raw potatoes will absorb the smell of onions when stored close together, which will come through in the flavor of cooked potatoes.” (PS—here’s how to store potatoes the right way.)
Related: 30 Tasty Potato Recipes
How to Store Cooked Onions
Storage for cooked onions is different than storage for raw onions. Here’s how to store cooked onions: “Like other leftovers, sauteed onions can be stored in an airtight container in the refrigerator for three to four days,” says Marcus.
Can You Freeze Onions?
Yep, you totally can freeze raw onions to make them last longer! Shaw suggests rinsing the onion under cool running water, then patting it dry, removing the outer layers and chopping as desired. Next, place them in an airtight container or resealable bag. “I personally like to place a paper towel inside the bag to absorb any moisture,” she says. Finally, label and date the bag and use the raw, uncut onions within a month, says Shaw.
Additionally, Marcus shares this tip for freezing raw, chopped onions: “Spread chopped onions into a single layer on a baking tray,” she says. “Then, place in the freezer for at least an hour before transferring to a zip-top bag. Store them in the freezer for three to six months.”
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How to Tell if Onions Have Gone Bad
It’s pretty easy to tell if an onion is past its prime. Shaw says you should be able to tell by the smell, first and foremost. “If it smells foul or off, then compost it or toss it,” she says. If there’s visible mold when you peel back the layers or the onion has a tender, squishy or slimy feel, then those are signs the onion has got to go, says Shaw. “To check whether an onion is still good, feel it with your fingers; the onion should be firm and not soft,” adds Marcus.
Sources
Melanie Marcus, RD, a culinary dietitian from the greater Charlotte, NC area
Elizabeth Shaw, RDN, president of Shaw Simple Swaps
