Want to tell if your onion is bad? You’re in luck. Well, not actually, since your onion went bad, but there’s lots of easy ways to tell if your onions are spoiled.

Soft, Mushy Texture

Brown color onion

One of the biggest giveaways of a rotten onion is the texture. Even if it doesn’t smell terribly, you definitely don’t want to eat a mushy onion.

If the whole onion is mushy, that’s a dead giveaway. If there are soft and mushy spots throughout, you’re better off not eating it.

However, one or two tiny soft spots might not be the end of the world. You could cut them off and cook the rest of the onion.

Dark Spots or Mold

Onions in a state of decomposition.

While mushy spots aren’t a death sentence, dark spots and mold are a really bad sign. If it’s gotten to the inside, you’re better off tossing it.

However, if the spots are really small and only on the outer peel, remove them and continue. As you’re peeling, keep an eye out for more black spots.

The best way to remove this mold is by rinsing it. To be on the safe side, give all your onions a quick rinse before cooking with them.

Unpleasant Odor

2 hands peeling an onion

Onions aren’t necessarily known for their pleasant smell. However, there’s a few specific scents to watch out for when trying to tell if an onion is bad.

A sour-smelling onion, for example, is not an onion you’ll want to eat. If it’s been rotting for a while, you’ll smell it before you slice it open.

Fortunately, the smell of a rotting onion isn’t subtle. You should be able to tell as soon as you start cutting, if not immediately after picking it up.

Sprouting

Growing red onion shoots

Sprouting doesn’t necessarily mean that the onions have gone bad. While they’re still edible in this state, it’s a sign that they’ll be rotting soon.

If your onions are sprouting, you should eat them as soon as possible. Simply chop off the sprouts and continue cooking them as usual.

You could also cook with them, if you’d like. Dice the sprouts, sautée them in a pan, and use them to garnish your next meal.

Dry or Wrinkled Skin

Red and gold bow

Like the sprouts, this isn’t the worst sign. The outer layer of an onion is supposed to be much dryer than the rest.

It becomes a problem, however, if it looks super dried out and wrinkly. Onions like these are still cookable, but won’t be for much longer.

If your onions look like this, then they might be getting old and close to rotting. Still, they haven’t gone bad yet. Cook them quickly.

Visible Insects or Eggs

Colorful Green housefly using its labellum to suck banana meat

If there’s insects crawling over your onions, do not eat them. People might joke about “extra protein,” but you don’t want to go down that road.

To make sure your onions are safe, check the root for white eggs. Those are laid by onion flies. (I feel nauseous just writing about this).

If there’s no eggs in your onions when you buy them, you’re all set. Store them in a secure place inside of your refrigerator to prevent this.

Discoloration of the Flesh

Closeup of many organic bulb onions on the shelf display for sale in the local grocery store for background.

You onion might be going bad if the first couple of layers look darker than usual. This is often accompanied by changes in texture.

As is the case with occasional soft spots, you can cut out brown spots on onions. Be quick to cook discolored onions, since they’ve almost gone bad.

If the whole onion is discolored, though, then it’s probably not good to eat. You can cut open the onion if you want to double check.

Slimy Outer Layer

Details of a sprouted onion, on a white background, with drops of water.

Slimy layers are a telltale sign that your onion is bad. You should be able to feel any slime as soon as you touch it.

If only a few spots are slimy, then your onion may be salvageable. This is especially true if slime is the only sign of spoilage there is.

However, if the inside layers of your onion are slimy, combined with discoloration or other indicators, then it’s a no-go. That’s a clear-cut case of a bad onion.

Off Taste

young woman in a gray aprons cuts red onion.

Onions have a pretty distinct taste. If they start tasting differently, then that’s not a good sign. If your onion is bad, it might have a bitter aftertaste.

That distinct taste is incredibly unappetizing. You almost can tell right away. Obviously we went over visual ways and using smell, but taste will give it away as well.

The texture itself changes but the spoiling is what really affects the taste. A “spoiled” taste is usually quite easy to point out.

Conclusion: Telling if an Onion is Bad

The onions started to sprout green

Onions are not an easy vegetable by any means. You have to be careful with it, be mindful of it, and always keep it stored properly. Never be sparing with onions though! They are just too good.