Why Do Onions Make You Cry?

Why Do Onions Make You Cry?

There’s some pretty neat science happening when you chop onions. Understanding that science is the first step in preventing the tears. And who doesn’t want to cry less? Here’s the real reason onions make you cry.

Can you imagine having to cook without onions? For all the tears and all the burning eyes, they elevate so many dishes to the next level. So in order to understand what it is that makes you have such a reaction to them while you’re cutting them, let’s get scientific.

When onions grow, one of the things they absorb from the soil is sulphur. Onions then turn raw sulphur into an amino acid called sulfoxide. When you cut an onion, it releases this sulfoxide, creating a gas. Receptors in your eyes then recognize the presence of an unfamiliar gas, and communicate with your brain to start the tears flowing in order to help protect your eyes from this compound.

The gas is only released when you’re cutting onions, though, as the process of cooking them gets rid of all the gas, and causes the gas-forming molecules to become inert. And that’s when the real magic happens, as those same enzymes are partially responsible for giving onions their flavor.

Watch the video for the real reason onions make you cry!