Hack #31: How to Chop an Onion (quickly, easily, and without crying!)

posted in: Food, Hack | 0

Oh, onions! I love their taste, how they smell when they’re slowly caramelizing in the pan, and I use them in most of the hot meals I make. Not to mention, they rank pretty high on the healthy scale too. This antioxidant-rich vegetable is packed with vitamins C and B6, and have been known to lower blood sugar, cholesterol, and high blood pressure. Even better, they are a low calorie, fat-free, and sodium-free food.


But…I absolutely loathe cutting up and onion. When a recipe calls for diced, minced, or chopped onion, I usually put it off until the very end. Not long after peeling an onion, my eyes start to sting, then burn, and finally tear up, sending me out of the kitchen to recover.

That is, until I learned how to cut an onion. I developed a process using tips and tricks I’ve gathered throughout the years, and while I am still rather impartial to cutting onions, this process makes it so much more bearable.


Onions contain sulfur dioxide. A lot of it. As you are slicing and dicing, the onion’s juices are releasing this tearful gas, which rises up into your eyes, mixes with your tears, and creates an acid that makes your eyes sting and burn. To combat this gaseous tear-jerking effect, you can do two things:

1. Use the sharpest knife possible. Most knife blocks come with a knife sharpener that typically just sits there and gathers dust. Use it! A sharper knife ensures you’re cutting through the onion, whereas a dull knife will squeeze down on the onion before breaking the flesh, which releases more of that sulfur dioxide.

2. Cut the onion near an open flame. This is the biggest tear-saver there is. The heat from the flame draws in the gas and burns it up before it can reach your eyes. Some suggest a candle, but I find candles a bit weak. I prefer to set up my cutting board on the front burner of my gas stove and turn on the back burner as I cut (do be careful when choosing this method). Alternatively, you can set your cutting board up on the countertop next to the stove and turn the front burner on.


Let’s talk about the most efficient way to cut an onion. The natural lines in the onion’s flesh make for an easy cut, if cut strategically. This method works best if you need a chopped or diced onion.

Step 1: Cut one of the ends off the onion. It doesn’t matter which end, but I typically cut off the stem end (the pointy end, opposite of the root). Then, turn the onion on its freshly cut end and cut a thin slice off the side of the onion. This will ensure that your onion won’t roll around while you’re cutting it.



Step 2: Lay the onion on its flat side and, while holding the root end of the onion, make several lengthwise (from stem to root) cuts that don’t cut all the way to the root. You want the root to stay intact so that you can keep your slices all in one place.




Step 3: Turn your onion 90 degrees and make crosswise cuts (from side to side) that are perpendicular to the first set of cuts you made. Keep cutting until you’ve reached the root.


That’s it! If you do it right, the onion pieces should just fall on to the cutting board. You may need to break up pieces that are stuck together, but it should not require much more cutting, unless you’re going for a minced onion.


Here are a few extra dos and don’ts when cutting an onion:

-Avoid using a fan or vent when you’re cutting the onion. You want the open flame to burn up the sulfur dioxide, and using a fan only sucks the gas away from the flame and up toward your eyes.

-When you’re finished cutting, rinse or wash your cutting board right away. The juices will stick around and keep releasing gases until you wash them away.

-Keep your hands away from your eyes during and after cutting an onion. Rubbing your eyes and touching your face will cause you to tear up. Also wash your hands with warm water and mild soap immediately after cutting an onion.



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