Why Do You Cry When You Cut Onions?
Just cutting an onion for the onion soup or stew, and there goes the mascara streaming down your cheeks again. What’s going on with those things? What makes you cry so much? And does putting a piece of baguette in your mouth help?
When you cut an onion, you damage the onion’s cells. This releases a gas called syn-propanethial-S-oxide. That gas combines with the moisture in your eyes to form sulfuric acid, an irritating acid that makes your eyes water. And once your eyes start watering, there’s more moisture, which means even more sulfuric acid…
Don’t rub!
What can you do about it? Rubbing doesn’t help at all; it only makes things worse. But a sharp chef’s knife does help. The duller the knife you use to tackle the onion, the more cells you damage. Experts also advise putting the onion in the fridge or freezer for a while before cutting it. That syn-propanethial-blah-blah is then no longer gaseous, which means less eye-stinging.
Under the tap
If you cut the onion under the tap, the long-name gas binds to the tap water, so no more watering eyes. But we still need to figure out how to cut an onion neatly under a running tap. Do glasses help? Only partly, because glasses don’t completely seal off your eyes, of course. If you really don’t want to cry and have lots of onions to chop, swimming goggles, ski goggles or a full-face helmet could be a solution.
Mussel shells on your ears
Experts also recommend putting a piece of stale bread in your mouth, with part of it sticking out. No idea how that would work, and it reminds me of the chef who advised an intern not only to put a slice of bread in his mouth to prevent watery eyes, but also to put mussel shells on his ears and a plastic bag over his hair. ‘None of it helps, but it looks good on him,’ the big boss told the rest of the kitchen staff.
