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Why does chopping onions make you cry?
It's not tears of joy that you shed while preparing these beloved bulbs.
Fri, Apr 01 2011 at 10:36 AM
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Q: I was making my mother’s famous French onion soup the other night and had to chop six onions. Before I was even halfway through the first one, I started to tear up. By the time I was on the second, it was a full-on sobfest. It got me wondering: Why does chopping onions make you cry?A: Firstly — can I get that recipe?
Secondly — eek. I hate cutting onions for that very reason.
It’s interesting, isn’t it? You can have whole onions sitting around your house for days, even weeks, and everything is just dandy. And then one day, you unsuspectingly cut into one, and ouch! Stinging and burning and crying (oh, my!) like you wouldn’t believe. So what gives?
Allow me to explain: Lachrymatory-factor synthase, an enzyme that was discovered by Japanese researchers in 2002, is released when you cut into an onion. This enzyme converts the onion's sulfoxides into sulfenic acid. The sulfenic acid rearranges itself into an unstable compound known as syn-propanethial-S-oxide. Once this compound reaches our eyes, it irritates them, causing the crying reflex to kick in to flush out the irritants.
That’s about all the chemistry I can take for one day. Now, on to biology …
There are three types of tears — basal, reflex and emotional. Basal tears keep your eyes from drying out, like on a windy day. Reflex tears clear your eyes of irritants, such as when you get dirt in your eye. And finally, emotional tears can be a result of happiness, sadness or any other emotion that gets your cry on. (For me, it’s watching the last scene of “Garden State” … or “Bambi.”)
The kind of tears you’re producing when you’re chopping onions is reflex tears, because your brain is sending the message to your eyes to flush out the unstable compound mentioned above.
So is there anything you can do to prevent it?
Well, a scientist at New Zealand’s Crop and Food Research Institute by the name of Colin Eady is working on creating a tear-free onion. That’s right, folks — no more crying. Using gene-silencing technology, Eady was able to shut down the lachrymatory-factor synthase gene and create an onion that did not induce tears. The onion is a long way from grocery store shelves, but we could be on our way in the next few years.
Until then, here are some other things you can try:
First, try sticking your onions in the refrigerator for a few hours before you cut them. Or the National Onion Association (yes, there is one) suggests cutting the top end of the onion off and peeling downward, but cutting off the root end (the one with all the hair on it) last. This is because the cells that release the onion's bountiful sulfur are concentrated at the base.
It also might help to peel the onions under water.
Finally, if you peel and chop a lot of onions, it might pay to get a little exhaust fan from your local hardware store. Having the air blow on the onion scatters the sulfuric acid and makes the irritant less potent. Check out Chow.com’s nifty little how-to video here.
That’s about all I've got on the onion front. I sincerely hope they hurry up and get those tear-free onions to us soon. If I hear any news, you’ll be the first to know. Until then, good luck chopping!
— Chanie
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I stick my onions toward the back of the fridge if I'm cooking them, they freeze part way there. Then I chop them up while there still half way frozen-- tear free. I could stick my face in them if I wanted to.
Yes, I cry at the end of Gardenstate <3 love that movie.
Great article. Was really just wondering this!
i buy frozen onion...and use more onion powder.
After cutting each end of the onion off, dig out the root end (the solid spot at the bottom). Makes sence that the vapors would be coming through the roots. I'm a chef and I chop a lot of onions, this method works for me.
light a candle (even unscented ones) and place it in the area where you will be chopping onions. Works every time.
Try using (swimming) goggles. Always works for me!
chewing gum helps cause it makes you breathe through your mouth.
I wear contact lenses and cutting onions never seems to bother my eyes. I guess the plastic lense protects it.
I'd rather wear protective eye-wear than eat an onion that I know is genetically modified. I know other foods are modified, but I guess it's different knowing for sure that something is modified just because it irritates peoples' eyes.
Chewing gum while cutting also helps!
Just put a match between your teeth. I heard this in the moive "The Help", I went home and tried it, surprisingly it works... how?? I don't know, but I promise it works.
Me too! I tried too, it and it works. (Remember to place it the right way, the head of the match points out of your mouth)
If you breathe through your mouth instead of breathing through your nose, you are less likely to tear up! Hey, it works for me!
All you have to do is rinse the onion with cold water before you start cutting.
Try sharpening your knife right before cutting an onion. This also helps in reducing eye irritation. The sharp knife cuts more precisely not breaking open the parts that release the irritants. I've tried it and it definitely helps. I learned this in the book "The Sharper Your Knife, The Less You Cry."
Simply have fan blowing across the area you are cutting the onions in and away from you. No tears..
try the glass of salts in front of you while cutting the onions, it worked!
Squeeze lime or lemon juice onto your onions before cutting them.
It Worked So Well
Cut near an open flame. The chemicals will burn up. Also, use a VERY sharp knive. The sharper the knive the less likely you'll cause these pockets of chemicals to exploded.
There will be no tears if you keep a pair of goggles in the kitchen and wear them while peeling onions, I always use them to protect my eyes whenI cook uaing ingredients that splatter. oil
I wonder if they will also elliminate the great taste when they elliminate the "crying" chemical?
I was wondering how I will be offending crying, but no bitting. Tanx for the lecture mother nature. lol
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