Why do onions make your eyes water?!

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I cook a lot with onions, and something that saved me was to get a really sharp knife (the duller your knife is, it will crush rather than cut the fibers, releasing the fumes). They go for about 50 - 80 dollars each (Such as J.A. Henckels) But they are so worth it! The day I got it, my eyes didn't even water a bit! You just have to have it sharpened every few months though and many chef/cutlery shops will offer this for free or little money once a month or so.

Another thing you can do is whistle while you chop! This helps prevent the fumes from getting in your eyes. Something else that can make it worse is if you are chopping directly over a floor vent, it can blow the fumes right in your eyes!

Good luck!

Onions are part of the plant genus Allium, which means it absorbs sulfur in the earth, which helps form a class of volatile organic molecules called amino acid sulfides, which make you tear up once you cut in!

You can keep from crying by refrigerating your onion before cutting it (slows reactions and changes the chemistry inside the onion) or by cutting the onion under water.

Enzymes that are released when you cut the onion cells react with your tears to produce sulfuric acid. Refrigerating the onion first may reduce the effect.

http://chemistry.about.com/od/chemistryf…