8 Ways to Help Chop Onions Without Tears
Eight science-backed methods to chop onions without crying, making your cooking experience comfortable and tear-free.
Chill the onion before cutting
Use a sharp knife
Chop under running water or in a bowl of water
Use a fan or kitchen hood for ventilation
Cut the top first and save the root for last
Light a candle nearby
Wear protective kitchen glasses
Use a food processor for quick chopping
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Chopping onions is one of the simplest cooking tasks — yet it’s the one that makes even experienced chefs tear up like they’re watching the saddest movie ever made. While onions taste amazing in almost every dish, they also release a gas called syn-propanethial-S-oxide when cut. This gas irritates the eyes, triggers tear glands, and turns meal prep into a watery struggle.
The good news? You don’t need goggles, magic tricks, or superhuman tolerance. There are practical, science-based ways to cut onions comfortably and tear-free. Here are eight easy methods that actually work — no crying required.
1. Chill the Onion in the Fridge or Freezer Before Cutting
Cold temperatures slow down the release of the tear-inducing gas inside the onion. That’s why chilling your onion before chopping can drastically reduce irritation.
How to do it:
Place the onion in the fridge for 30–60 minutes, or
Put it in the freezer for 10 minutes if you’re in a hurry
Cold onions release fewer vapors, making chopping much more comfortable. Just don’t freeze them solid — it alters the texture.
2. Use a Sharp Knife to Minimize Cell Damage
A dull knife crushes the onion instead of slicing it cleanly. This crushing releases far more irritants into the air.
Use a sharp knife because it:
Cuts clean edges
Damages fewer onion cells
Reduces the amount of gas released
Makes slicing faster and smoother
A sharp knife isn’t just safer — it’s your best defense against onion tears.
3. Cut the Onion Under Running Water or in a Bowl of Water
Water attracts and dissolves the irritating compounds before they reach your eyes.
Two easy methods:
Rinse the onion and slice it under a thin stream of running water
Or keep a bowl of water and chop the onion inside it
Yes, it’s slightly messier — but extremely effective. Many home cooks swear by this technique.
4. Keep a Fan or Ventilation System Running Nearby
Airflow disperses onion fumes quickly, preventing them from rising toward your face.
Try placing:
A small electric fan behind your cutting board
Your cutting station near an open window
The onion directly under a kitchen hood or extractor fan
The airflow pulls gases away from your eyes, giving you a tear-free chopping experience.
5. Cut Off the Top First — and Save the Root for Last
The root end of the onion contains the highest concentration of tear-triggering compounds. Cutting it first releases a big wave of irritants.
Instead, follow this order:
Slice off the top (stem end)
Peel the onion
Cut it into halves
Chop normally
Leave the root end intact until the very end
This technique significantly reduces exposure to irritants.
6. Light a Candle Near Your Cutting Board
This old kitchen trick is more scientific than it looks. A candle flame helps burn or absorb some of the irritating gas molecules before they reach your eyes.
How to do it:
Place a candle or tea light near the cutting area
Make sure it’s positioned safely
Chop as usual
The flame acts like a mini “fume filter,” reducing the amount of onion vapor around your face.
7. Wear Simple Kitchen Glasses (Not Goggles!)
You don’t need professional goggles — even basic kitchen glasses or clear protective eyewear help block the irritants from reaching your eyes.
Benefits:
Protects eyes without fogging
Lightweight and comfortable
Cheap and reusable
Works for chopping multiple onions
If you cook often, keeping a pair of glasses in the kitchen drawer can save you a lot of tears.
8. Use the Food Processor for Fast, Minimal Exposure
When you want chopped onions but don’t want the fumes, a food processor is a lifesaver.
How to use it effectively:
Roughly chop the onion into chunks
Pulse a few times until you reach the desired size
Quickly open the lid away from your face
Minimal knife contact means minimal gas release — and minimal crying.
Why Onions Make You Cry (Quick Science)
Onions contain sulfur compounds that become irritating gases when their cells are broken. These gases react with the moisture in your eyes, creating mild sulfuric acid — which your eyes flush out with tears.
The more cell damage, the more gas.
The more gas, the more crying.
That’s why proper technique makes such a big difference.