Why do onions make you cry?

Man crying while chopping onions
Is that a tear in your eye or is it just the onions? (Picture: Getty)

Onions are one of the most popular vegetables for cooking, with the bulbous plant used in everything from Italian to Indian cuisine.

But for many people, chopping the humble onion is a painful experience – with an eye-watering stinging sensation a common problem.

It seems cruel that such a delicious food staple makes us shed a tear.

But why does this root vegetable make us cry, and how can we avoid turning on the waterworks when cooking with them?

Why do onions make you cry?

Onions contain sulfur compounds – a natural smelly chemical also found in garlic.

When sliced or cut into, the vegetable releases one of these compounds as a gas, called propyl sulfoxide, which is an irritant.

Child is practicing to cut onions.
Onions release an irritant gas when cut into that stings our eyes. (Picture: Getty)

This chemical works as a defence mechanism in nature to ward off animals from eating the onion.

But when we chop them for cooking, the gas reacts with the water in our eyes and we shed tears to flush the chemical out.

Some people have more sensitive lacrimal glands, the tear ducts in your eyes, than others, which is why not everyone is affected by chopping onions in the same way.

The onions that contain the most sulfur compounds are the yellow, red, and white ones, meaning these are more likely to make you cry.

Onions of different varieties
Yellow, red and white onions are more likely to irritate your eyes. (Picture: Getty)

Sweeter green onions have less sulfur and therefore could be a good option for those who are particularly sensitive to the sting.

For those who don’t want to risk it, Waitrose is going to start selling a type of onion that doesn’t make you cry – called Sunions.

How can you chop onions without shedding a tear?

There are a few tips and tricks you can try to stop yourself from getting weepy while dicing and slicing.

One option is to chill your onions for 30 minutes or put them in iced water before cutting into them, as the cold apparently stops the sulfur from being released into the air so easily.

A woman cutting an onion wearing goggles to stop herself from crying.
Goggles can offer some protection when cutting onions. (Picture: Getty)

Another idea is to cut off the root end first, as this lets most of the irritant gas escape, before you peel the skin off and get chopping.

Using a sharp knife is also recommended, as blunt ones do greater damage to the onion’s cells which makes it release more eye-stinging chemicals.

TikTok user @partyshirt went viral on the platform in 2021 for their genius onion hack.

They suggested putting a wet paper towel down on the cutting board – the idea behind this is that the acid onions release is attracted to a water source, and so goes to the towel instead of the tear ducts in your eye.

The TikTokker successfully demonstrated the hack in their video, with bone-dry results.


Onion hack? via @cerealeatingghost

♬ original sound – PARTY SHIRT

An alternative fool-proof way to fend off that nasty sulfur, you can try using goggles to cover your eyes. Contact lenses offer some protection too.

Hopefully one of these methods will make your next onion chopping experience a little less emotional.

MORE : McDonald’s worker reveals the different types of onions used at the fast food chain

MORE : Woman reveals easy method to make crispy onion rings without using a deep fat fryer

Follow Metro across our social channels, on Facebook, Twitter and Instagram

Share your views in the comments below

Leave a Reply

A note to our visitors

This website has updated its privacy policy in compliance with changes to European Union data protection law, for all members globally. We’ve also updated our Privacy Policy to give you more information about your rights and responsibilities with respect to your privacy and personal information. Please read this to review the updates about which cookies we use and what information we collect on our site. By continuing to use this site, you are agreeing to our updated privacy policy.

%d bloggers like this: