I Wonder Why – Why Onions Make Me Cry?

Why do onions make you cry?

● When you slice through an onion, you break open several onion cells. Some

of these cells have enzymes inside of them, and when they are sliced open, the

enzymes escape.

● The enzymes then decompose some of the other substances that have escaped

from sliced cells. Some of these substances, amino acid sulfoxides, form sulfenic

acids, which then quickly rearrange themselves into a volatile gas.

● The gas reaches your eyes and reacts with the water that keeps them moist. This

changes the chemical’s form again, producing, among other things, a mild

sulfuric acid, which irritates the eyes. The nerve endings in your eyes are very

sensitive and so they pick up on this irritation.

● Peeling the onion and then chilling it in the refrigerator before you slice it will

minimize the release of gas.

● Another easy solution is to cut the onion under water or run the tap over it as you

slice.