Why Onions Make Us Cry...and Other Food Mysteries Solved

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Why do onions make us cry?

Do you regularly experience stinging eyes and tear up uncontrollably while chopping onions? Don't worry, you're not alone. This phenomenon all comes down to biochemistry. When slicing into an onion, you're triggering a chain of chemical reactions, and certain molecules in the onion's tissues turn into an unstable sulfur-containing gas known as allicin. This gas interacts with your eyes, creating that awful burning, itchy sensation and making your tear ducts overflow. And apparently, this chemical response is simply the onion plant's way of protecting itself from damage.

So how can we prevent this unpleasant chemical response? Always use a sharp knife and try peeling, halving and chilling your onions beforehand. Cold temperatures are known to make the gas less volatile.