What happens if you eat a bad onion

Wondering “What happens if you eat a bad onion?

Have you ever experienced chopping some onions for your beef steak recipe and suddenly noticed you accidentally purchased a bad batch? 

If you answered yes to both questions, then you’ll certainly find this guide useful.

Onions are a staple in many households, and they also happen to be one of the most commonly used vegetables.

Whether you’re a vegetarian or enjoy cooking meat dishes, onions are indeed a must-have ingredient for your kitchen.

And on top of that, they have so many health benefits;

They contain phytonutrients that may help prevent cancer and other diseases and of course even provide relief from allergies (especially hay fever), asthma, atherosclerosis.

Not only this, but onions can bring your dish to a whole other level too, thanks to all the flavor that’s packed in this tiny ingredient.

However, regardless of how amazing onions may be, we can’t help but think about what happens when we eat bad ones.

Well, you don’t have to think about that much longer because…

We’ve taken the time to answer all your questions and concerns!

(Pretty awesome right?)

Now without further ado,

Let’s start with…

Do Onions Go Bad?

do onions go bad

Before we start answering your question, you need to first understand onions and their chances of spoiling.

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It can be confusing to know if onions go bad especially when you’ve not personally dealt with one.

Many people claim that onions don’t go bad, while some don’t agree with this. However, to give you a better understanding, you need to know that:

Onions are one of the vegetables that hold high water content since it’s a vegetable that’s grown in the ground as opposed to on a vine.

Moist vegetables contain water and are considered perishables because they can spoil more quickly than dry goods like whole grains or beans.

Generally speaking,

Onions do go bad and this happens because of the water content they contain.

This vegetable is 90% water and can become moldy when there is too much moisture because of excessive exposure to air or if they’ve been cut for a long time without being used immediately.

There are many ways to determine if an onion has gone bad and these are:

Mold spots on the Outer Layer

mold spot

Among the most common sign that the onion has gone bad is if it starts to grow mold on the outer layer.

This is an indication that this particular onion has been sitting around for a while and bacteria has set in, causing it to rot from within. Usually, this bacteria is from the soil that the onion was grown in.

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You can simply remove the layer in which you notice mold developing and place your onion inside your fridge if you don’t plan to use it any time soon.

However, if you see that molds are developing inside the onion already, it’s best to discard the onion as it is not safe for consumption.

Dark Brown Streaks

Onions are either white or purple. However, if you notice brown streaks on the outer layer of the onion that look like wood grain, it means that the onion is overripe and should be discarded.

Brown streaks happen when the moisture inside the onion has already turned to sugar and oxidized.

dark brown streaks

Don’t worry though! There’s no need to throw away an entire onion just because of brown streaks.

You can usually peel the outer layer with the brown stains and have a good-quality, flavorful onion on your hands.

A Putrid Smell

We all know that onions have a strong smell that might be a bit annoying to some people.

However, if you start noticing a putrid smell coming from the onion, it means that it has gone bad and you should get rid of them immediately.

A putrid smell can form because of rotting or because the onion has  been left out for too long.

The best thing to do would be to cut off the rotten part of the onion and try again.

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If this happens to your onions, don’t worry: there are some other ways you can use them in cooking before they go too far.

When all of these signs show up,

It’s best to know which ones to keep and which ones to discard because undesired things can happen when bad onions are consumed

And we’ll all talk about it in the next section

Which is….

What Happens If You Eat a Bad Onion

what happen when bad onions go bad

Nothing’s worse than preparing your favorite cheesy baked onion only to realize that your onions in your pantry have already gone bad.

It’s too late to head to the grocery store and you need to have dinner ready in a few minutes.

You then wonder if eating bad onions is harmless…

Well, to address your concern, if you decide to eat bad onion, you’ll end up with some nasty side effects.

You may experience stomach discomfort and nausea, and you’ll most likely have an unpleasant taste in your mouth for the next couple of hours.

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And trust me, water won’t be able to wash that taste out!

Bad onions can also lead to bad breath, as bacteria will start producing hydrogen sulfide gas when it reacts with sugar found on destroyed cells inside the onion.


Eating bad onion can not only affect your health but also the outcome of your dish since bad onion will make your food smell and taste bad.

So if you don’t want your family members to start throwing up during dinner,

We recommend you discard any onions that are wilted, slimy, or have black spots on them because they may not be safe for consumption.

Luckily, there are ways to ensure that this doesn’t happen to your precious vegetables

And we are all going to discuss it

But first, let’s have…

The New Learnings

It’s certainly a relief to know a thing or two about your everyday vegetable right?

You’re pretty much aware now that onions:

  • Go bad because of the high water content.
  • Have signs you need to look out for to determine if it’s bad.
  • Can give you unpleasant side effects when consumed.
  • Make your dish smell and taste bad.

With this learning, you can now ensure the safety of yourself and your family.

You won’t ever have to risk your lives eating a bad onion because you’ll know how to catch one before it makes its way to your dish!

Now that we’ve got that settled,

Let’s head on to…

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How to Properly Store Your Onions

how to properly store an onion

Just like any perishable goods, onions need proper storage to ensure they stay fresh for as long as possible.

If you don’t want to constantly end up with bad onions, proper storage must be strictly observed.

When it comes to storing, an onion’s mortal enemy is humidity, heat, and air exposure. These elements can highly affect onions and make them go bad much sooner.

When ignored, you’ll surely end up wasting both your vegetable and money!

In order to preserve the freshness of an onion,

It is highly recommended that you store them in a cool and well-ventilated area such as a pantry with low humidity levels.

If you don’t have either one of these places available, just use your cabinet since putting onions in a cool and dark place can also be just as effective.

You can also store it in the refrigerator, make sure to store it tight to a plastic bag or container so that your refrigerator won’t stink!

In addition, it is also a good idea to remove the outer layer of each onion since this part tends to be too moist and will make them go bad faster than if they were left on.

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Also, make sure you keep your onions away from light to avoid spoiling due to oxidation. If you fail to do so, environmental elements such as bacteria, fungi, and germs can start to grow on them.

Moreover, it can make your entire kitchen stink too!

And we wouldn’t want that, won’t we?

Now that we’ve got it covered,

We can proceed with the next section which is…

How Long Do Cut Onions Last

It’s a common mistake for people to cut too much onion, perhaps even more than they could ever use. 

If this has happened to you, then you’ve most probably wondered how long will those cut onions last.

To answer your question directly, cut onions could last up to one week and three months when placed in the fridge.
cut onions

So if you want to keep them for a longer time, just chop and store your onions in an airtight container and place it in your fridge.

This life hack is practiced by many people around the world and you can even dice your onions so you don’t take much time preparing them for a dish.

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After three months, they will start to go bad but that’s still way better than throwing them away right after cutting them!


We can’t deny the fact that we’ve learned so much in this section.

You now know how to properly store onions and how long cut onions would typically last.

With this learning, you’re sure to prolong the life of your precious vegetable so you get the most out of your money!

Before you try out all your new acquired learnings,

Let’s finally have the…

Last Words

Indeed, the onion is one of the best ingredients you can ever put in a dish.

It’s versatile and offers every user countless benefits, whether it’s health or even flavor.

In this article, you’ve finally learned

  • How to check if the onion is bad.
  • What happens when you eat bad onion.
  • The proper way to store onion

How long a cut onion lasts.

And along with that learning, you can be confident with every dish you set out because…

Gone are the days of risking your health and wasting onions.

Be sure to keep this guide in mind so you can make the best out of those onions!