Fun fact: The original title of the Bob Marley classic “No Woman, No Cry” was actually “No Onion, No Cry.”
Okay, so maybe that’s not true, but it hints at a prevailing kitchen truism: If you’re gonna cut an onion, there’s gonna be some waterworks involved.
But oh little darling, don’t shed no tears: There are actually a few tricks to help keep your eyes dry through the onion cutting process. So grab your best kitchen knife – and put that hanky away.
So let’s get to it: Why do onions make you cry anyway?
Well, a lot of that has to do with allium, the same smelly substance that gives garlic, shallots, chives and leeks their unique odors and peppery kick. The compound works by drawing in sulfur from the soil as the plants grow underground, creating a group of chemicals inside the onion called amino acid sulfoxides.
Now, we must admit, we’re pretty big fans of the stuff: allium byproducts in plants like onions and garlic have been linked to a number of health benefits, including lower blood pressure and cholesterol levels, better cardiovascular elasticity and less fatty triglycerides in the bloodstream.
But the pungent secret ingredient of sulfur is also what triggers the tears when an onion’s cut open.
Since their strong smell attracts many would-be animal diners in the wild, the onion had to come up with an even stronger defense mechanism. What they settled on was a group of enzymes that break down their sulfur deposits into a few unpleasant elements, including syn-propanethial-S-oxide, the gaseous substance that gets released from an onion when it’s cut and sticks to the vulnerable membranes surrounding our eyes.
So how can we enjoy all the healthy goodness and earthy taste of an onion without weeping over how beautiful the whole process is? Well, we’re glad you asked!
For every tear-free onion cutting suggestion out there that actually works, there are at least 100 off-the-wall ideas and old wives’ tales, including everything from holding a piece of bread in your mouth through the process to covering your knife in lemon juice before the deed is done.
While these might be great strategies for weird and smelly times in the kitchen, they’re a little lacking on the tear-reduction front.
Unfortunately, there’s no perfect solution – short of a GMO sulfur-free onion – to keep the tears completely away. But there are a few tried and true methods that will help you get through the process on a limited number of Kleenexes.
The first cut is the deepest – so make it a good one.
The dreaded syn-propanethial-S-oxide is only released when damage is done to an onion’s cells, so minimize that damage by ensuring your knife is especially sharp, which will help you slice through those cells as efficiently as possible.
It’s also helpful to have a plan of attack before you start hacking away. Keep in mind whether you want your onion diced, sliced or ringed and make only the cuts you need to get there.
And while you’re going about the process, remain mindful of the exposed onion. You might want to only peel the parts you’re working with, and definitely keep any exposed cuts face down on the cutting board, or at least facing the opposite direction of your face.
Just be careful when chopping off the onion’s root – especially if you’re particularly sensitive to the sulfuric effects. The area holds the motherlode of syn-propanethial-S-oxide, releasing a huge bloom of the gas when it’s separated from its bulbous baby.
Another way to keep some sulfur at bay is by giving your onion a little bath before slicing it open.
Peeling your onion and allowing it to soak in a small bowl of water for a few minutes before making the first cut can help wash away some of the sulfuric compounds on an onion’s outer skin, reducing – but not eliminating – the plant’s irritating material.
Still, we’re admittedly not the biggest fans of this method, since the water also works to dilute that awesome oniony flavor, and could make the cutting process more slippery – and dangerous.
Another way to make water work in your favor is by freezing the amount of it found in an onion.
Popping your onion in the freezer before cutting into it does diminish the plant’s eye-dampening effects, with a lower inner temperature leading to a less volatile gas and a limited spread of the noxious stuff. (Thanks, science!)
But in order for the solution to work, you’ll need to remember to freeze your onion ahead of time – and not forget to take it out of the fridge. And a frozen onion will also be slippery and hard to cut, making the slicing process more difficult and potentially dangerous.
Perhaps the best solution is also the simplest.
If you’ve ever wondered what that big hood on top of your stove is for, it’s exactly moments like this. Inside the hood is an exhaust fan, which works to suck up anything from steam rising off a hot pan to – you guessed it! – any spare syn-propanethial-S-oxide floating around.
Place your cutting board nearby, flip the magic switch, and proceed on a mostly tear-free journey to onion cutting town.
Nearly every oven out there has one, but if yours doesn’t – or you just don’t have access to a stove at the moment – you can also try cutting your onion near a fan or open window (though this will be less effective).
But we hope you find some of these tips helpful at home, because cutting an onion without crying is such a beautiful experience, it may actually bring you to tears.