News Physics These simple knife tricks stop onion tears instantly Sharper knives in slower hands may prevent crying when cutting onions ⏸ Chopping onions releases a tear-induing chemical into the air. Careful cutting techniques stop it. chiinka/Getty Images By Carly Kay October 27, 2025 at 11:00 am Read another version of this article at Science News Explores Share this:Share Share via email (Opens in new window) Email Share on Facebook (Opens in new window) Facebook Share on Reddit (Opens in new window) Reddit Share on X (Opens in new window) X Print (Opens in new window) Print It’s your kitchen. You can cry if you want to. But with sharper knives, you might not need to. Cutting onions slowly with sharper knives slashes the number of tear-inducing droplets the vegetables eject into the air, researchers report in the Oct.