While chopped onion is kept in deep freezers for a longer time and then kept at room temperature inside an airtight container it still remains good

  • 7
    Hello, and welcome to Stack Exchange. While your title is clear, the body of your question doesn't make any sense. Would you edit it to make what you're trying to say clearer? Mar 10, 2017 at 12:59
  • 3
    If your intent was to answer your own question, you can ask a question and then provide an answer, or provide an answer as you ask the question - both of these are preferable over writing the answer in your question, as it makes the question itself very confusing.
    – Zibbobz
    Mar 10, 2017 at 13:44
  • related : cooking.stackexchange.com/q/6658/67
    – Joe
    Mar 10, 2017 at 17:45
  • This one's been around for 6 weeks in a plastic bag: twitter.com/HalfOnionInABag
    – miken32
    Mar 10, 2017 at 17:46

4 Answers 4


Keep the skin on a full half, seal it, and store it face down in the fridge.

Cooks Illustrated

Other half same thing but no skin.

  • The rolling around is a bad argument, since you can store it upright. But the moisture kinda makes sense, Mar 10, 2017 at 19:30
  • @IsmaelMiguel I make no rolling around argument.
    – paparazzo
    Dec 10, 2017 at 16:47

The onion should be stored in cool, dry conditions (e.g., the inside of a refrigerator). It should not be exposed to air, as this will cause it to oxidize (i.e., react with the oxygen molecules present in air). We can combat this issue by placing the cut onion in an airtight plastic ziploc bag, or encasing it in plastic wrap. The plastic-covered cut onion should then be placed in the refrigerator, where it will preserve its freshness for up to two weeks. If you begin to notice dark spots, then the onion is beginning to spoil. These dark spots can be removed by simply slicing them off; alternatively, you can avoid spoilage altogether by freezing the cut onion in an airtight plastic encasing until its ready for use.

  • This is somewhat of a relief to me, as I'm used to putting my onion halfs in ziplock bags and putting them in the fridge - I've always been worried about whether or not they'd be fresh a week later, and now I know!
    – Zibbobz
    Mar 10, 2017 at 13:45
  • Even better than a Zip-Loc bag: vacuum-seal the onions (works for most other cut vegetables, too).
    – user21524
    Mar 10, 2017 at 16:01

As with nearly all vegetables, if you want to maximize fridge life of cut raw onions, make sure you use well-maintained tools that cut cleanly - sharp knives, or if machines are used, sharp and good quality blades. Rough tools (blunt machine blades, serrated knives...) will rip the top layer of the cut pieces apart, causing more water loss, more enzymatic activity and more oxidation.


We do it this way. Cut onion amount you need off. Leave skin on the rest. Place in a small plastic butter cup like butter comes in from the store. Put on lid. Set on top shelf in the fridge door so it gets used first before starting a new onion. Chopped onion can be stores same short term in fridge door. Easy to grab & use there.

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