Know Your Onions: Why Chopping Them Makes Us Cry

Why does chopping onions make you cry?
Why does chopping onions make you cry?

There are times in the kitchen when wearing glasses – or even swimming goggles – can be an advantage.

As a fashion statement it might not be “The Look” of choice; but it is preferable to having your face smeared with long black streaks of mascara. While for weeping male chefs, there is the danger of being considered a tad too much in touch with their feminine sides.

Yes, you’ve guessed it, we’re talking about the perennial problem of onion-chopping here. Whether it is for winter soups, autumn sauces, spring or summer salads; onions are the mainstay of any kitchen store cupboard. With many varieties to choose from, these versatile vegetables have one thing in common: they make your eyes water. And their preparation is a constant source of anguish for any cook with half way sensitive eyes.

Over the years I have tried several cures for the problem – from slicing with a hunk of bread in my mouth, to doing the chopping with wet hands … all with limited success. In my kitchen in Spain we have an onion rota system which involves always having one onion in the fridge and remembering to replace it after use. Even the super-fiery Spanish onions are slightly more eye-friendly after a cool down before chopping.

But why do onions – and even some of their close relatives from the garlic family – make us cry?

Apparently it is all to do with a very mild sulphuric acid which is released when onions are cut. As the gas escapes into the atmosphere it irritates the surface of the eyes. This is when our tear glands go into over drive to wash away the irritant and the rest is – as they say – is culinary history: streaming eyes but a very tasty meal.