Avoid Watery Eyes After Cutting Onions With This Unexpected Step

Few things push a person to the brink of absurdity like the quest to chop onions without crying. The hunt for relief has made people do all sorts of seemingly ridiculous things such as wear swimming goggles in the kitchen, chew mint-flavored gum, cut allium on a damp paper towel, or even place a spoon in their mouth while chopping onions – all because the internet swore it would work. Spoiler: it didn't. If you've given up on trying not to cry and just need a way to stop the tears fast, a trick you might actually want to try is sticking your head in the freezer. It won't make you look any less ridiculous, but at least the tears will stop.

Whether you're chopping them in bulk to make foolproof caramelized onions or stock your pantry with crispy fried onions, the first step to easing your post-chopping pain is understanding what's really going on. When you slice into an onion, you break into its cell walls and unleash sulfuric compounds into the air. One of them turns into a gas that reacts with the moisture in your eyes to create sulfuric acid, which triggers the familiar flood of tears. 

Like all enzymes, the one responsible for this chain reaction (alliinase) requires just the right conditions like a neutral pH and a temperature of about 104 degrees Fahrenheit. But stick your head in the freezer — or even chill the onion beforehand — and those ideal conditions vanish. The cold temperature slows the enzymatic reaction down, so it can't produce as much of the tear-inducing gas, giving your eyes a break.

You can also use the same science behind that freezer trick in a way that feels a little less absurd. Cold air provides instant relief because it slows down the irritation process, so you can get a similar effect without sticking your head next to the frozen peas. Try a cold compress, instead. Simply soak a clean washcloth in cool water, wring it out, and place it gently over closed eyes for a minute or two. The chill calms the burning and reduces inflammation, giving your eyes a much-needed reset.

If the sting lingers, there are a couple more things you can do. For example, try splashing your eyes with cold water to wash away any remaining irritants. If that's still not enough, use eye drops or artificial tears to help flush out the last of those pesky, sulfuric compounds. Otherwise, you can also mess with the onion's chemistry after it's been chopped to stop the irritation. 

Just like how lowering the temperature makes things harder for the tear-causing enzymes to flourish, so does dumping your chopped onions in a bit of vinegar. What happens here is that it changes the pH around the enzyme, making it less effective at producing the irritating gas. Basically, whether it's cold air or a splash of acid, all you need to do to stop the tears is disrupt the enzyme's comfort zone.