Why do onions make you cry, and how can you prevent it from happening? They’re made up of a tunic of outer leaves (the brown layer), scales (the white firm juicy edible part), and the basal plate (often called the “hairy part” or the “root”). When you cut the basal plate or shoot, they release an enzyme. That enzyme reacts in the rest of the onion to release a gas. When that gas combines with water, it creates an acid. If that water is in your eye, you have acid in your eye.
TIP: use chopped onions within 24 hours. They become infested with bacteria and can make you quite ill especially for immune repressed person.
- Use a very sharp knife when cutting onions. The enzymes are released when cells are broken or crushed; using a sharp knife slices through the onion rather than crushing and thus, fewer enzymes are released. Regardless of whether you employ different tactics too, use a sharp knife in every onion-cutting situation. It’ll go that much quicker!
- Chill the onions in the freezer for 10 to 15 minutes before cutting them. This reduces the amount of the acid enzyme released into the air and has zero effect on taste. This was found to be the most effective way to reduce tears by the television program Food Detectives.
The fridge can do it, too; just make sure not to keep them next to apples or potatoes, or leave them in there for too long (20 minutes should do it) — they can cause odors if you do.
- Cut the onion under water. This is an effective method, but the problem is that it’s a bit difficult to maneuver. In the water, the onion bits go every where unless you hold onto them and then scooping them up and draining out the onion water and it can all just not be worth it if you don’t execute it right. If you choose this method, plan out your attack beforehand.
Some say to do it under running water, but this is a bit tricky, too, obviously. The gushing water makes everything go a little haywire in your hands.
- Cut the onion near hot running water or a cloud of steam. Steam from a kettle or pan of water will do the trick. The science here is that the steam will draw out the vapors from the onion, dissipating them.
- Breathe through your mouth and stick your tongue out. This draws the gas over your wet tongue. The olfactory nerves, which are closely located to the tear duct nerves, will be by bypassed and there will be no tears generated. This is easily confirmed when you forget and breathe through your nose. Instant tears!
- Soak the onion in water. The enzyme is denatured by the water-air boundary. However, do know that this eliminates some flavor and that the onion is a little more slippery than normal (making it harder to deal with). If milder onions are okay for you, give this method a shot.
- Point your knife away from the tubes. Because onion “flesh” is tubular in construction, pointing the tubes away from you while cutting will keep the onion from spraying in your eyes.
Of course, a breeze of any kind can send the fine, misty spray toward your eyes, so pay attention to air currents too. Turn that fan on — and point it in the right direction!
- Whistle while you work. Whistling makes a significant airflow, specifically away from your face, which keeps the onion mist away from your eyes. Just pick a catchy tune that you won’t want to stop whistling and you can cut as many onions as you need.
- Stick a piece of bread in your mouth. Many people report that chewing, especially bread, helps avoid tears when cutting onions. Chew very slowly, letting the bread hang out of your mouth a little. Your mouth will water, which will be a little uncomfortable, but your eyes won’t! Others say to chew gum. There’s no real reason this might work, but you could give it a shot!
- Wear gas-tight goggles or a mask. If you have a pair of swimmer’s goggles or chemistry goggles that fit your face, this is one of your best bets. No onion air will be getting in there! But if they don’t fit your face, you’re just cutting an onion with weird glasses on, crying all the while. Be wary of the one-size-fits-all onion goggles you can find online. The odds of them fitting aren’t 100%. And if you have glasses? You’re better off with a different method.
- Cut the onion next to a strong draught from a fume hood, fan, or window. This is so that the gas is pulled away from your eyes. Get to chopping on your stove and use the vent (be sure to blast it at full power) that comes up above. Or just get next to an open window or get outside and enjoy the breeze.
- Wear contact lenses. They create a barrier between the surface of your eyes and the gas. If it’s this or glasses, definitely go for lenses!
Use some type of acidic solution. An ionic or acidic solution can denature the enzyme. Here’s a couple home remedy solutions from around the house:
- Put vinegar on the chopping board. The acid denatures the enzyme.
- Soak the onion in salt water. The ionic solution denatures the enzyme. But do know that this can change the flavor.
- Use the candle method. Light a candle and set it near the cutting board before cutting the onion. The gas released by the onion is drawn into the flame of a candle. Not your best bet, however. Some say it just masks the smell and doesn’t actually work. But hey, your kitchen will smell nice! Remember to blow it out after you’re finished cutting the Sweet onions, like Vidalias, are less cry-inducing. Consider using these instead.
- This is my personal favorite! While wearing kitchen gloves zest a lemon and place it within where you are cutting your onion. Or put a small amount of juice in a nearby bowl. The acid from the lemon draws the smell of the onion away fom your eyes. Then I add a bit of the zest or juice to whatever I am making to draw the flavor out into the dish!
What do you do to stop the tears?
This article is part of the Tips That Help in the Kitchen Series, Tip Friday.