Home › Home & Kitchen › Kitchen & Dining › Cutlery & Knife Accessories › Chef's Knives How to Cut an Onion Without Crying Published: July 9, 2026 · Updated: July 9, 2026
Photo: Michael Browning CC0 1.0 Source
Chill the onion in the fridge or freezer for 10–15 minutes, use a sharp knife, and leave the root end intact until last — that's where the tear-causing compounds are most concentrated. A sharp blade crushes fewer cells so it releases less of the irritant, and cutting near an open window or fan carries the fumes away from your eyes.
Recommended Chill the onion, use a sharp knife, keep the root intact, and cut in moving air — Onions make you cry because cutting ruptures their cells and releases an enzyme that forms a volatile sulphur gas; it drifts up, reacts with the moisture in your eyes to form a mild acid, and stings. Everything that helps works by making less of that gas or moving it away. Chilling the onion in the fridge or freezer for 10–15 minutes slows the reaction and lowers how much gas escapes. A sharp knife is one of the biggest helps, because it slices cleanly instead of crushing and bursting cells the way a dull blade does. Most of the irritant sits in the root (basal plate), so leave the root end on, cut around it, and slice it last. Keep the fumes away from your face with moving air — chop next to an extractor fan or open window, or aim a small fan across the board. Other tricks that genuinely help: cut near a lit candle or gas flame, which burns off some of the gas, and wet the knife or rinse the onion. If you're very sensitive, sealed goggles are the only sure fix, and working quickly means less time in the fumes.
