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How To Tell If An Onion Has Gone Bad

When it comes to telling whether or not a food item has gone bad, it can sometimes be a somewhat tedious and difficult task, especially if it’s not obvious whether or not something has gone bad, and if you don’t know what signs to look out for, then you could very easily end up using something which should have been thrown out weeks ago.

How To Tell If An Onion Has Gone Bad

One of the food items in question is onions, as people have difficulty trying to figure out whether or not they’ve gone bad or not.

So, if you’re looking for a guide on how to tell if an onion has gone bad, then look no further, as we’ll provide you with all of the signs of a bad onion, as well as how to store your onions to ensure that they don’t go bad too quickly! 

How To Tell Whether An Onion Has Gone Bad Or Not

Although it’s usually pretty hard to know whether or not your onion has gone bad, or simply has marks from its storage and travel to the grocery store, there are three key factors that will help you to determine whether or not an onion has gone bad. 

The first of which is  the smell, and although it’s fair to say that onions aren’t particularly the best-smelling vegetable out there, when they begin to go bad, their scent does begin to change as they begin to go off, and it’s noticeably different from that of a ripe onion. 

The second way to tell whether or not an onion has gone bad or not is to check whether or not your onion has begun to develop dark spots, which is another major indicator of an onion going bad (see also “How To Check If An Orange Is Bad“).

These dark spots later go on to develop into mold, which is a particularly clear sign that something is wrong with your onions! 

Finally, the final way of telling if an onion has gone bad or not is its texture and feel, and if you’re purchasing your onions individually, then it’s worth giving them a feel before you decide to go ahead and purchase them (see also “Signs That A Tomato Has Spoiled“).

Onions that are beginning to go bad will often have soft or mushy spots, so if you have suspicions that your onion has gone bad, then be sure to check for any soft spots. 

How Long Do Onions Last? 

So, now that you know how to tell whether or not your onions have gone bad (see also “How Can You Tell If Broccoli Is Bad?“), why not learn a little bit more about how long onions last, which will ensure that you always use up your onions before they go bad! 

As a general rule, whole onions will last anywhere from 2 to 3 months when stored in a cool, dry place, which means keeping them in somewhere like your pantry, or your cellar, will provide the perfect conditions for your onions. 

Some people may prefer to store their onions in the refrigerator, where they’ll actually last for the same amount of time, although they’re likely to go slightly soft due to the extra moisture. 

If you have to keep your onions at room temperature though, then unfortunately they’ll go bad quicker, and will only last 4 weeks before they need throwing away, but this is still plenty of time to use them up! 

How To Store Cut Onions

If you’ve cut or peeled your onions, then you might be wondering exactly how you can store them to ensure that they’re still okay when you’re ready to use up the rest of the onion.

Thankfully, storing your partially used onions is much easier than you might think! 

Place your onions into a resealable plastic bag or airtight container and place them in your fridge, and they’ll be able to last another week to 10 days, so you can easily use them the next time you cook with onions. 

If you’ve cooked onions and have leftovers, then place them in an airtight container and into the refrigerator, where they’ll last for four days before you need to throw them away, which is plenty of time to eat them! 


So, whilst many people find it hard to distinguish between a good onion and a bad onion, by looking for the three key signs, which are the smell, texture, and dark spots, you’ll easily be able to tell whether your onions are good to eat or not. 

Onions will typically last for two to three months if stored properly, or at least 4 weeks when stored at room temperature, so you shouldn’t have to worry about using your onions too quickly once you’ve bought them!

Justin Roberts