Why do Onions make you cry, and how do you stop it ?

Answer 1

Onions ....

Onions contain a substance called a lachrymator, which is released into the air when the vegetable is peeled or cut. When these vapors combine with moisture from your eyes, sulfuric acid is formed, resulting in a painful burning sensation and tears. There are several ways to prevent " onion tears. "

You can cook pearl onions whole, before peeling, for example. When this technique isn't practical, try peeling the onion while holding it under cold running water. Generally, if you use a sharp knife and make quick work of chopping onions, tears won't be a problem. And , indeed, soft vegetables like onions are best chopped by hand. If you use a food processor, pulse gently off and on to avoid mashing the onion.

Good luck! _;-)

Answer 2

As any chef knows, cooking an onion produces a very strong aroma that most people enjoy. But cutting up an onion stings your eyes and makes you tear up uncontrollably. If you love to include onions in your dishes, you're probably frustrated by this all the time. So just what is it in onions that make them such an ordeal to prepare?
When you slice through an onion, you break open a number of 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 (this is why our eyes sting when we slice onions). The brain reacts by telling your tear ducts to produce more water, to dilute the irritating acid so the eyes are protected. Your other reaction is probably to rub your eyes, but this will actually make the irritation a lot worse, of course, if you have onion juices all over your hands.

Oddly enough, this volatile compound is also responsible for a lot of the great taste in onions, as well as the pleasant aroma when you cook the vegetable. You'll also get sulfenic acids by cutting up garlic, chives and leeks, among other vegetables, but they don't form the same irritating gas, just a strong smell.

There are all kinds of remedies for dealing with this irritating phenomenon, some more effective than others. As a general rule, move your head as far away from the onion as you can, so the gas will mostly disperse before it reaches your eyes. If you really can't stand the tears, the simplest solution might be to wear goggles. This measure is very effective, but it may seem a bit extreme to those around you, and if your kitchen is steamy, you might not be able to see what you're doing (never a good idea when you're using a knife).

Peeling the onion and then chilling it in the refrigerator before you slice it will minimize the release of gas somewhat, because the change in temperature alters the compounds in the onion. Cooking an onion before you slice it will work also, for the same reason. Another easy solution is to cut the onion under water or run the tap over it as you slice.

Some people say if you hold a lemon, piece of bread or a sugar cube in your mouth, the food will absorb the gas before it reaches your eyes. Breathing with your mouth, instead of your nose, might also help because as you inhale, you suck the gas in and as you exhale, you blow it away. This keeps a lot of the gas from ever reaching your eyes.

Answer 3

As onions are sliced, cells are broken open. Onion cells have two sections, one with enzymes called alliinases, the other with sulfides (amino acid sulphoxides). The enzymes break down the sulphides and generate sulphenic acids. Sulphenic acids are unstable and decompose into a volatile gas called syn-propanethial-S-oxide. The gas then dissipates through the air and eventually reaches one's eye, where it will react with the water to form a dilute solution of sulphuric acid. The sulphuric acid irritates the nerve endings in the eyes, making them sting. The tear glands then produce tears to dilute and flush out the irritant.


Supplying ample water to the reaction prevents the gas from reaching the eyes. Therefore cutting the onions under running tap water or completely under water can help, as can rinsing the onion and leaving it wet while cutting. Chilling the onion will prevent the enzymes from activating, which will limit the amount of gas generated. Some people will freeze their knives to enhance this effect. Finally, using a sharp knife will limit the cell damage, and therefore prevent the release of enzymes.

Different species of onions will release different amounts of sulphenic acids, thus some will cause more tear formation and irritation than others.

The characteristic odor of onions can be removed with lemon.

Answer 4

I forgot what the chemical is that's the onion juice , but that's what gets us. I've heard(didn't work for me) that a glass of water next to the onion,while you're cutting it helps..Some are stronger than others.If I can get some ventilation, & not be directly over the onion when I'm cutting it, that helps. Also , if you use a SHARP knife it goes thru the onion easier & does'nt squeeze as much juice out

Answer 5

I am not sure what it is in the onions that make you cry. But my mom always put a piece of bread in her mouth when she chopped onions. I used to think it was silly until I tried it one day--it works! Just tear off a small piece of bread and hold it in your mouth when you are cutting up onions and you will not cry.

Answer 6

I have heard a lot of ways but most dont work - I tried this once and it does work even though u look stupid doing it. Wear a mask (snorkel and mask type) it prevents anything getting to your nose or eyes and it doesnt burn ur eyes or make them water.
Some other things i heard of are to put things in ur mouth - a lit match (not actually lit though), a piece of bread, fruit - apples, lemon and there are a lot more but i dont think a lot of them work. There was something that you put i ur mouth - cant remember what it was - that was meant to absorb the stuff coming from the onions so it didnt get to your nose or eyes - think it was a lemon or some sort of fruit. Hope this helps

Answer 7

they don't really make you cry...they burn your eyes because the smell is strong, and your eyes just water a little. i used to work at Subway, and would cut onions two hours a day, but if you put onions in water for a few minutes before you cut them, that works great.

Answer 8

Try cutting a small slice from each end of the onion and then place in plastic wrap or baggy and refrigerate. You won't tear from the onion then. Works, try it.

Answer 9

I keep the onions under cold running water in a bowl or something whilst im chopping them...it works 4 me.

Answer 10

Not sure why they make you cry but if you wear contact lenses your eyes don't water when cutting onions.