How to Store Cut Onions

The refrigerator makes storing partial onions a breeze. All you have to do is cover your cut onions appropriately, and they can stay fresh until you are ready to use them up. Try these two techniques, depending on whether your onion has been diced or sliced in half.

How to Store Half an Onion
Store half an onion in the refrigerator, cut side down, wrapped tightly in plastic wrap or in a plastic bag. Leave the outer peel on if possible to reduce moisture loss.

How to Store Chopped Onions
Store chopped onions in the refrigerator in an airtight container or plastic bag.

Now that you know how to store cut onions in the refrigerator, you may wonder how long they will stay fresh. Storing leftovers in the fridge dramatically increases their shelf life, but they won't last forever.

Half of a cut onion will last up to two weeks in the fridge, when stored properly. The cut side may dry out slightly, so feel free to slice off and discard the dried part.

Chopped or sliced onions have a slightly shorter shelf life. They’ll typically stay fresh for 7-10 days.

Fresh onions are firm, smell fresh, and are free from brown spots and other discolorations.

If your chopped onions aren’t firm anymore or don’t have much odor, then avoid using them raw. They won’t taste very good raw, but they will be fine in a cooked dish (which relies less on the crisp texture and bright flavor of the onion).

If your cut or chopped onions are mushy or slimy, discolored (brown or black spots), leaking fluid, or smell rotten, then it is time to throw them out!

Fact or Fiction: Can bacteria be dangerous in leftover onions?
A recent internet rumor suggests that using leftover onions can be dangerous due to bacteria growth, but this is a myth! Onions can of course harbor bacteria that can make you ill, but it’s no more dangerous to use leftover onions than it is to use any other leftover vegetable. Simply follow proper food safety precautions, like keeping your vegetables and food prep area clean, storing food at the correct temperature, and throwing out leftovers when they no longer look safe to eat.

If the onion has only been in the fridge for a few days, you can use it as you would any onion. Use it in salads, on sandwiches, in recipes, and more.

If the onion stays in the fridge for a week or more, it’s best to use it only in cooked dishes for the best flavor.

If you need some inspiration, here are some of our favorite recipes that use a lot of onions! Try one today. They're all delicious and easy to make.

Multi Bean Soup with Caramelized Onions
Easy Pasta with Caramelized Onions and Spinach
Slow Cooker Pot Roast Loaded With Garlic and Onions
Baby Blooming Onions
Homemade French Fried Onions
Fried Onion Mashed Potatoes
Dump and Go Amish Casserole