Chopping onions often leave tears rolling down our cheeks. The tears come because our eyes are irritated by droplets the onion releases. It turns out when you cut an onion, it releases a gas called syn-Propanethial-S-oxide. These gases then get to your eyes and create a mild acid which irritates the eyes.
However, rubbing your eyes is a bad idea, since your hands are likely full of the tear making onion juice. The eyes tear up to protect themselves. Five ways to cut onions without shedding tears:
1. Cut while chewing gum
Sounds fancy, right? Well, it works magic! The theory is that having something in your mouth encourages you to breathe through your mouth, sucking in the droplets before they hit your eyes.
2. Freeze the onion
Put the onion in the freezer for about 5 minutes before cutting it. The theory with this is that the cold inhibits the onions’ release of its eye-irritating chemicals. However, it will be a little tougher to cut and it will be more difficult to remove the outermost layer.
3. Chop with a very sharp, stainless steel knife
Chop with a very sharp, stainless steel knife that has been run under water before starting to slice. If cutting a lot of onions or even a single large one, run knife frequently under water. The water will help absorb the sulphur compounds and a sharp knife will make a cleaner cut, bruising the onion cells less which theoretically means causing less reaction.
4. Light a candle nearby
It is believed that the flame will take away some of the onion fumes that cause tears. Cut onions as close to the flame as possible without danger of being burned. The heat will draw the sulphur to it and away from your eyes.
5. Cut the onion under water
Cutting an onion under water will prevent the sulphuric compounds from reaching your eyes and causing you to tear. However, an alternative to this is to cut the onion into two equal parts and soak them in water for about 5 minutes before chopping.
