Why Do Onions Make You Cry?
The Reason Chopping Onions Makes You Cry—and 7 Ways to Prevent It
You are in the zone—preparing dinner like a professional chef. You are salting meats with finesse, flipping veggies in the pan with a flick of the wrist and maybe even dancing your way to the refrigerator. But then it hits you. Waves of tears start pouring down your face. It happens every time, but you don’t know why. It feels like there is no way to stop it. The dreaded onion strikes again! The act of chopping onions can make even the most experienced chef cry and completely derail a dinner party. But why do onions make you cry in the first place? The team at Visionworks explains the reason behind those dreaded onion tears and offers tips on how to cut an onion without crying.
Here’s Why Onions Make You Cry
You’ve researched the best foods for eye health and started to prepare a healthy meal rich in Vitamin A, omega-3 fatty acids and leafy greens. Dinner prep is going smoothly when BAM. You start tearing up as soon as you cut into an onion. But why? Carrots don’t cause us to tear up, so why do onions make us cry?
It turns out that the reason onions make us cry starts below ground. While onions grow in the soil, they absorb sulfur, which they use to produce amino acids. When we cut into an onion on the chopping block, we break open the fibers and release the liquid contents inside. Enzymes and sulfur-rich amino acids then meet and form sulfenic acids, which produce a chemical called syn-propanethial-S-oxide. This chemical is volatile and quickly evaporates into a gas, moving from the cutting board up to your eyes. When syn-propanethial-S-oxide gas comes in contact with the eyes, it causes a burning sensation. So, the brain triggers a response to rinse away the irritant and produces tears. So, chopping onions releases a gas that can burn the eyes and to protect them, our brain makes us cry.
To summarize, onions make us cry because:
- Onions absorb sulfur when they grow.
- Chopping onions releases enzymes and sulfur, which combine to form sulfenic acids.
- Sulfenic acids produce syn-propanethial-S-oxide gas, which irritates the eyes.
- The brain triggers a tear response to protect the eyes from irritation.
7 Ways to Cut an Onion Without Crying
There are many theories on the best ways to cut an onion without crying. Our team at Visionworks has seven suggestions.
Substitute Another Seasoning for Onions
The best way to avoid tears is to cut out onions all together. To bypass crying at your dinner party, try other seasoning options like garlic, chives, leeks, scallions or fennel. These vegetables offer similar flavors without all the tears. In some recipes, try using onion powder or dried minced onions to get a rich flavor without all the chopping and crying.
Use a Sharp Knife
Onions make us cry because the liquid inside produces a chemical that irritates our eyes. Using a dull knife to cut an onion rips the onion, which then releases more of the tear-inducing gas. Instead, try using a sharp knife to make a clean cut, thus reducing the amount of syn-propanethial-S-oxide produced.
Put Your Onions in the Fridge First
Cold temperatures can make syn-propanethial-S-oxide gas less volatile, which means fewer tears. Try chilling your onions in the fridge before peeling and chopping them. It may seem like a strange hack, but it totally works! Make sure to refrigerate your onions for at least 30 minutes.
Open a Window
Give your eyes a break by opening the kitchen window for better airflow. Opening the window can help disperse the syn-propanethial-S-oxide gas. Plus, you can enjoy the beautiful weather outside!
Cut Your Onions Under a Vent Fan
If you don’t have a window in your kitchen, don’t worry. Stove vent fans can also help vent away syn-propanethial-S-oxide gas and protect your eyes from irritation. Turn on your vent hood and chop onions nearby to get relief from teary eyes.
Wash Your Hands
When working in the kitchen, it is always important to wash your hands. After chopping an onion, make sure to clean your hands well and try rubbing your palms with a lemon wedge in addition to soap and water. Thorough washing helps remove any lingering acids on your fingers and prevents more tears.
Protect Your Eyes
One of the best ways to relieve eye irritation is to prevent it before it starts. Wearing protective eyewear, glasses or sunglasses can help prevent the syn-propanethial-S-oxide gas produced by chopping onions from entering and irritating the eyes. Before you reach for the cutting board, grab your glasses!
How to Protect Your Eyes and Prevent Onion Tears
Prescription glasses, sunglasses and even custom safety glasses help shield your eyes from irritants, including syn-propanethial-S-oxide gas made from chopping onions. Wearing one of these forms of eyewear while chopping onions is a great way to prevent tears.
Schedule an eye exam near you with a top eye care professional at your local Visionworks store to get a new pair of glasses. Once you have an updated prescription, you can shop hundreds of eyeglasses and sunglasses styles both in-store and online.
Professional chefs value precision. Protect your eyes and get the clear vision you need to chop onions like a pro!
Information received through Visionworks® content is for informational purposes only and does not constitute medical advice, medical recommendations, diagnosis, or treatment. Always seek the advice of your eye doctor, physician, or other qualified health provider with any questions you may have regarding a medical condition.
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