How to chop an onion without crying
Why onions make you cry, and the four small adjustments that mostly stop it.
Lila Park
February 8, 2026
Why onions make you cry
Cutting an onion ruptures cells that release sulfur compounds. These react with the water in your eyes to form a mild sulfuric acid.
Your eyes flush it out with tears. This is reflex, not allergy — there's nothing wrong with you.
Four things that actually help
Chill the onion 15 minutes in the fridge before cutting. Cold reduces the volatility of the sulfur compounds.
Use a sharp knife. Dull knives crush more cells, releasing more compounds.
Cut near a running fan or open window — moving air carries the gas away from your face.
Breathe through your mouth, not your nose. Anecdotal but consistent: it shifts how the gas reaches your tear glands.
Things that don't really work
Goggles work — but you look ridiculous and they fog. Onion-cutting glasses are sold but rarely make it into regular kitchens.
Bread in your mouth, lit candles, holding water under your tongue — all internet myths with no real evidence.
People also ask
Are red onions less likely to make me cry?+
Slightly — they have a lower concentration of the offending compound. White onions are the worst offenders.
Does freezing onion stop the tears?+
Mostly yes, but frozen onion turns mushy when thawed. Fine for soup, bad for salad.
Why doesn't this happen to chefs?+
It does — they just work fast and the eyes adjust over time. Sharp knives plus practice.