I have sensitive eyes. Or so I thought while furiously chopping onions on my cutting board to avoid the waterworks that
quickly ensue. I cook a lot and since onions are the backbone of many recipes, I chop a lot of onions. Recently it struck
me—with tears dripping down my face—that rushing blindly through my chopping, wielding a very sharp knife, was perhaps not a
brilliant idea. That got me thinking about the best (and the safest!) way to chop an onion to avoid tearing up.
There are a lot of suggestions out there: Some people swear by holding a piece of bread in your mouth while cutting onions.
Others say cutting them next to a candle or under running water helps. I’ll admit, I haven’t tried all the tricks.
After trial and error, below are a few tips I’ve found that really work:
1. Dice, Don’t Chop, Your Onions
Dicing and chopping are two different things. Dicing is neater and more calculated (see below) and chopping is a little more,
well, rough. And as it turns out, rushing through the chopping process haphazardly was costing me a lot of tears. In my
attempt to make the situation better, I actually made it worse. Here’s why: The chopping action damages the cell walls of the
onion, causing a cascade of events—including the release of the “onion lachrymatory factor” or LF—the chemical that irritates
your eyes. The more membrane damage to the onion there is, the greater amount of the chemical is released. You can minimize
the cell damage (and the tears) by dicing the onion instead. Cut the onion first in half through the root and flower end.
Peel back the skin and slice the onion halves vertically almost through to the root and flower ends using the natural “lines”
of the onion as a guide. Then make a few cuts horizontally (your knife will be parallel to the cutting board), again almost
through to the root and flower ends. The final step is to cut the onion vertically again, perpendicular to your first cuts,
giving you a perfect dice. Cutting it this way leaves more membranes intact and, hence, less tearing.
2. Chill Your Onions Before Cutting
Onions don’t like to be stored in very cold places, but before you cut into one, you may want to consider letting it cool off
a bit. In On Food and Cooking, Harold McGee suggests letting the onion sit in a bowl of ice water for 30 to 60
minutes before cutting into it. The cold slows down the LF factor, making it easier to chop tear-free. You can also try
sticking your onions in the freezer for a half hour or so before you’re ready to cut—just don’t forget about them!
3. Wear a Barrier
Ever notice that your contact-wearing friends shed less tears when they tackle onions? That’s because they have a physical
barrier that protects part of their eyes from the onslaught. For non-contact-wearing folks, onion goggles are a good choice.
I use them a lot when we’re testing recipes in the Test Kitchen, where we might have more than one person chopping onions at
the same time. They’re basically slimmed-down safety goggles. They may look a little funny, but they work!