MUNDANE MYSTERIES: Why Does Chopping Onions Make You Cry?

Hand cutting red onions on cutting board.

MUNDANE MYSTERIES: Why Does Chopping Onions Make You Cry?

This happens to me every time I make guacamole. EVERY TIME! That’s really the only thing I chop onions for. But why do they do that?

Onions actually produce a chemical irritant known as syn-propanethial-S-oxide. As you cut the onion that gets into the air and stimulates the eyes’ “lachrymal glands”. As they become irritated that’s what produces the tears!

So to recap, a chemical you probably can’t even pronounce is what makes you turn into a weeping baby over your cutting board.

 

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