You've been chopping onions all wrong—and science plus a chef reveal the tears-free secret
Onions have a notorious reputation for making eyes sting. A professional chef, Ian Sutton, has a counterintuitive routine that starts before you touch the knife. “Once chilled, the onions can be halved and chopped,” he said, explaining that storing peeled onions in an airtight container in the fridge slows the release of the sulphur compounds that trigger tears. “The cold temperature slows down the release of sulphur compounds that make you cry.” This method is about more than temperature. It’s a precise sequence of prep and timing designed to minimize onion juice reaching your eyes.
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Prep for tears: chill, seal, then dice
Ian Sutton recommends peeling the onions while they are still whole and storing them in an airtight container in the fridge before you cut. When you’re ready to dice, halve the chilled onion and chop. Keeping the root end intact helps hold the onion together and reduces tears because the root contains the highest concentration of sulphur compounds.
Sharp knives and roots: the technique that protects your eyes
A very sharp knife is essential. A blunt blade can crush cells and squeeze out more tear-inducing juice. “A blunt knife will often mean that the chef is pressing down too much and squashing the onion and rupturing the cell walls.” Leaving the root end intact during cutting also helps with stability and tear reduction. The message is simple: clean cuts, careful technique, and less tear spray.
A maths detour into onion slicing
Dr Dylan Poulsen, an associate professor of mathematics at Washington College, uses calculus to suggest a center-point below the onion’s center as the ideal target for even pieces. “Using calculus, I found that to minimise the variance of the area of the onion pieces, a chef should aim at a point under the centre of the onion that is 0.55730669298566447885... onion radiuses beneath the centre of the half-onion.” In plain language, this means aiming roughly halfway down the onion’s height rather than at its exact center. “If you try to hit that point with your cuts, rather than aiming at the centre of the onion, the resulting pieces will be more even.” Poulsen notes the ideal is based on an unrealistically infinite number of layers; real onions typically have seven to thirteen layers, and most cooks make no more than ten cuts. Separately, Cornell University researchers found that sharper blades reduce spray: “Blunter blades increase both the speed and number of ejected droplets,” and “Faster cutting also resulted in more juice generation, and thus more mist to irritate the eyes.”
From tears to texture: patience and another kitchen hack
Sally Abé, a Michelin-starred chef, shares a crucial secret for perfect scrambled eggs: patience. “To end up with silky pillows of scrambled eggs, patience is key.” Her method is simple: crack two eggs per person into a small bowl and whisk until yolk and white are fully blended. Season with salt and pepper, then melt butter on gentle heat until it just starts to bubble. Add the eggs and stir with a spatula, letting them rest for 10–15 seconds before continuing to stir until they form soft pillows. Remove from the heat when the eggs are three-quarters cooked and give one final stir before serving—the residual heat will finish cooking them. For extra richness, stir in a spoonful of crème fraîche.
