Jacques Pépin's Ultimate Tip For Cutting Onions Without Tears

It's an age-old problem that affects all cooks, from the novice to the 50-year professional veterans: Onions make people cry. Not with soul-crushing insults or belly laughter — but with chemistry. And we're usually willing to give onions a pass since they create the basis of so many delicious dishes. 

Healthline explains that onions contain a pretty effective way of protecting themselves from hungry rodents that may disturb their roots when they are maturing underground (and above ground when faced with a hungry human). Certain natural enzymes and sulfenic acid release when their protective skin is pierced or disturbed, creating propanethial S-oxide, a compound that turns into sulfuric acid when it touches moisture, i.e., the water in your eyes. What results is that burning, tear-inducing sensation you are all too familiar with.

Cooks have been attempting to gain an upper hand in this chemical warfare for years, suggesting many home remedies to keep the tears at bay. From holding an unlit match between your teeth to placing a piece of bread in your mouth, per Christy Davis Interiors, each method is an attempt to provide a sob-free onion-cutting experience. 

Cookbook author, television host, and French cuisine extraordinaire, Jacques Pépin takes a different approach that involves nothing extra. It's just you, your knife, and your frenemy — the onion.

Sharpen those knives

According to the Institute of Culinary Education, Jacques Pépin explains that your best defense mechanism is to disturb the onion as little as possible, which might sound impossible considering the fact that you intend to dice or slice it into small pieces. But if you use a sharp knife, you're actually causing less disturbance to the flesh than you would if you were using a dull tool, having to saw or crush the onion, thus releasing more irritating gasses.

Pépin isn't the only chef who believes in such a theory. Professional chefs and knife shop purveyors Jacqueline Blanchard and Brandt Cox tell Food & Wine the same concept that a sharper knife will cause less juice to seep out of onions. Ree Drummond, also known as The Pioneer Woman, also confirms that a sharp knife will do the trick, although chilling your onions may also help. 

Still, other professional, familiar names in the food world have their own methods of keeping their eyes dry when slicing onions, like Alton Brown, who insists that using a fan to waft away the onion fumes is fail-proof. Even if none of these tricks work for you, tearing up may be a small price to pay for creating the many wonderful dishes that require onions.