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Save halved & cut onions for later without losing freshness
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If you only need to cook with a portion of an onion, you may be wondering what to do with the rest. Fortunately, it’s safe and easy to store cut onions in the fridge or freezer. Simply place the halved or chopped onion in an airtight bag or container and keep it in the fridge for 1 week or the freezer for up to 8 months. We spoke with plant and gardening specialist Olivia Choong to learn the best ways to store cut onions, how to use them, and other ways to preserve onions. Read on to find out more!

Best Ways to Store Cut Onions

Wrap half an onion in plastic wrap and keep it in your fridge’s crisper drawer for 7-10 days. Or, store large and small pieces in an airtight container. To freeze onions, chop them and place them in a freezer-safe bag or container. Keep them for up to 8 months.

Section 1 of 4:

Storing a Cut Onion in the Refrigerator

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  1. Minimize exposure to harmful bacteria by preventing cross-contamination with uncooked meat and dairy products. Wash your hands before cutting the onion, use separate cutting boards for meat and produce, and ensure your knife is clean. [1]
    • If you have space, set up dedicated areas for produce and meat preparation so you don’t spread germs while cooking.
    • Avoiding cross-contamination is especially important when preparing food for storage because storing food gives bacteria time to grow.
  2. If you have half of an onion remaining or a few large wedges, wrap the cut side tightly in plastic wrap. Plastic wrap insulates the onion from the outside air while helping it retain moisture. [2]
    • Tear off a piece of plastic wrap big enough to cover the cut onion. Place the cut side down on the plastic and wrap the excess over the rest of the onion.
    • The plastic wrap also helps prevent onion odors from stinking up your refrigerator.
    • Tip : Keep the skin on the rest of the onion. The papery shell helps protect onions from drying out. [3]
    • There are also new, silicone products designed to stretch over and cover the exposed side of cut produce. Exercise caution when using these with onions. These products might not fully cover the onion, which can cause your refrigerator to smell.
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  3. Watermark wikiHow to Store a Cut Onion
    Both onion halves and chopped pieces store well in airtight plastic bags. Simply place the pieces in the bag, press out the excess air, and seal the bag closed. [4]
    • Do not use cloth storage bags, as these are intended for whole produce and will not protect a cut onion from exposure to air.
  4. Watermark wikiHow to Store a Cut Onion
    Glass and plastic food storage containers are great for storing onion halves, slices, and chopped pieces. Add the onion into the container and press or snap on the lid so it’s airtight. [5]
    • Make sure the container you use has an airtight seal. An airtight seal helps the onion last longer and prevents smells from escaping.
    • Opt for glass storage containers when possible, as they do not absorb odors, unlike plastic containers. [6]
  5. Aluminum foil works similarly to plastic wrap, protecting onions from air exposure and preventing smells from seeping into your fridge. Tear off a strip of foil, place the cut side of the onion face down, and wrap the rest of the foil over the piece. [7]
    • For extra protection, wrap the onion in plastic wrap and then cover it with aluminum foil.
  6. Place cut onions inside onion-saver containers as an alternative. Onion-savers are round, airtight containers made specifically to store halved and cut onions. Simply place your onion pieces inside and twist or snap on the lid.
    • These containers are helpful to have as they can prevent your other food storage containers from absorbing onion odors.
  7. Always store cut onions in your refrigerator instead of at room temperature. Place them in your fridge’s crisper or vegetable drawer to keep them cold and protect other foods from absorbing onion odors. Just use them within 1 week of storing them. [8]
    • Make sure your refrigerator is set at or below 40° F (4° C). Low temperatures inhibit bacterial growth and allow you to safely use the onions later.
    • Store all cut onions for the same amount of time regardless of variety. Even though you may find different storage recommendations for different onion varieties—such as yellow, white, red, pearl, or Vidalia—these recommendations are relevant only for whole onions, not for cut ones.
    • Warning : Ignore any storage recommendations that suggest cut onions can be stored at room temperature. Some common tips include storing onions in a bowl of water on a countertop. This approach only promotes bacteria growth. [9]
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Section 2 of 4:

Freezing a Cut Onion for Extended Storage

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  1. Watermark wikiHow to Store a Cut Onion
    Large pieces of onion—like an onion half or wedges—do not freeze well. To freeze cut onions effectively, chop your remaining onion into small pieces, preferably 1 4 inch (6.4 mm) cubes. [10]
    • Smaller onions freeze more evenly whereas larger sections often become freezer burned.
  2. Watermark wikiHow to Store a Cut Onion
    Choong says to put the chopped onions in a plastic freezer bag or a freezer-safe container made of either glass or plastic. Just make sure the onion is spread out as thinly as possible in the storage container you use. [11]
    • The thinner you spread the onion, the more evenly it will defrost when you’re ready to use it.
    • Choong says that you don't have to blanch onions beforehand if they're chopped.
    • Optional step : Place the chopped onions in a single layer on a baking sheet and freeze for 1 hour before placing them in a bag or container. This can keep them from sticking together. [12]
  3. Watermark wikiHow to Store a Cut Onion
    If you’re using a plastic bag, write the date directly on the bag. If you’re using a container, write the date on a label or piece of tape and stick it on the container. [13]
    • It’s easy to forget when you put something in the freezer. Having the date written on your onion container will ensure that you don’t lose track of when you stored it.
  4. Freezing chopped onions helps them last longer, but they’ll still degrade and go bad with time. Just set the bag or container in your freezer and make sure to use them within 8 months for the best taste and quality. [14]
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Section 3 of 4:

Using Refrigerated or Frozen Onions

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  1. Watermark wikiHow to Store a Cut Onion
    Check for signs that the onions have gone bad. Throw away any onions that appear cloudy, mushy, slimy, or moldy. Then, smell the onions to make sure there is no unusual odor. If they smell strong or unpleasant, put them in the trash. [15]
  2. Watermark wikiHow to Store a Cut Onion
    Sauté, roast, grill, or caramelize your cut onions and serve them in dishes like normal. Or, serve the onions raw on top of sandwiches and salads. [16]
    • It is safe to eat cut and refrigerated onions raw. [17] However, they may taste more harsh or even sour compared to fresh onions.
    • If you’re concerned about food safety, cook refrigerated onions instead of eating them raw. The heat helps kill off any potentially harmful bacteria that grew during storage.
    • Note : The cut side of the onion may dry out in storage. Simply cut off a thin slice to remove the dried pieces.
  3. Onions lose their crunchy texture when frozen and can become soft and mushy when cooked. So, cook frozen onions in stews, soups, casseroles, and other dishes where the onion’s soft texture is less noticeable. [18]
  4. Don't worry about thawing your frozen onions before cooking them. In fact, defrosting onions before cooking can lead to a mushier texture. [19]
    • If you only need to use a small portion of your frozen onion and the pieces are frozen together, run the container under warm water until you can separate the amount you need.
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Section 4 of 4:

Other Ways to Preserve Leftover Onions

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  1. If you don’t want to store leftover cut onions in the fridge or freezer, pickle them! Pickled onions keep well for 6 months in the fridge when unopened and last 2 weeks in the fridge when opened. [20]
    • To pickle the onions : [21]
      • Slice the onions into ¼ inch (0.6 cm) rings or pieces.
      • Heat 1-2 c (237-473 ml) of water to a boil.
      • Bring 6 tbsp (88 ml) of apple cider vinegar, ¼ tsp (1 g) of sugar, and ¼ tsp (1.5 g) of salt to a simmer.
      • Place the onions in a sieve and slowly pour the boiling water over them.
      • Put the onions in a sterilized jar (such as a canning or mason jar).
      • Pour the vinegar mixture into the jar. Choong says, “ensure that there is an inch [2.5 cm] of headspace” between the liquid and the top of the jar and “no air bubbles.”
      • Seal the jar and let the mixture cool before putting it in the fridge.
  2. Use dehydrated onions in place of fresh ones in recipes, or pulverize the dried flakes to make onion powder. Just store the dried onions in an airtight container in a cool, dry place for up to 1 year. [22]
    • To dehydrate onions : [23]
      • Choong says to peel off the skin and slice the onions thinly, about â…›-¼ inch (0.3-0.6 cm) thick.
      • Heat your dehydrator to 130-140° F (54-60° C).
      • Place the onions in a single layer on the dehydrator rack.
      • Dry the onions for 3-9 hours.
      • Let the onions cool and pour them into a clean, airtight container.
      • Check for moisture in the jar every day for 1 week. If you see moisture, dehydrate the onions again. [24]
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Community Q&A

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  • Question
    How do I store Vidalia onions uncut, with the skin on?
    Community Answer
    I would just put them in a dry, dark place. Keep them in the packaging they came in, or store them in a plastic container.
  • Question
    How can I store several kilos of cut onion?
    Community Answer
    If you have the room in your freezer, then that´s an effective method. If you can, freeze the onion spread out on a sheet and then place it in containers, that way you can pick out the exact amount you need later.
  • Question
    Can I chop onions in advance?
    Community Answer
    Yes! I always chop one or two onions into small pieces and store them in a Ziploc bag; they'll keep very well for a week or so. You can store them in plastic containers if you prefer, but it can be a challenge to get the onion smell out of the container.
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      Tips

      • It is a myth that cut onions are poisonous or bacteria magnets. Leftover onions are safe to eat when cut with clean tools on clean surfaces and stored in airtight containers in the fridge. [25] In fact, onion juice has antibacterial properties. [26]
      • Store all cut onions the same, regardless of variety.
      • Make sure to select onions that are in good condition so they last longer when stored. Avoid onions with dark marks, bruises, or soft spots.
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      Warnings

      • Don’t confuse storage instructions for cut and whole onions. Cut onions need to be stored in the fridge or freezer, while whole, uncut onions are stored in a cool, dry, and dark place.
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      About This Article

      Article Summary X

      To store a cut onion, start by wrapping large pieces of the onion in plastic wrap. Put smaller pieces in a resealable bag. Put the onion in your fridge and use it within 7-10 days. If you want to store a cut onion for longer, start by chopping it into small pieces and putting it in a freezer bag. You can store the onion in a freezer for 6-8 months.

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