Kitchen Confidence

How to Chop an Onion

By • July 10, 2012 • 23 Comments

Inspired by conversations on the FOOD52 Hotline, we're sharing tips and tricks that make navigating all of our kitchens easier and more fun. Today, how to chop an onion.


Chopping an onion isn't rocket science -- in fact, it's one of the first things you learn in the kitchen. Whether you're a first-timer or an old hand, today we have a primer on the various ways to chop an onion: dicing, slicing (two ways!), and a coarse chop. Merrill said something funny when we were discussing this Kitchen Confidence how-to: "It doesn't really matter how you cut an onion, but if you don't do that right, why do anything right at all?" We agree.

One thing we don't have an answer to is how to avoid teary eyes while chopping. Advice runs from the sensible-sounding (keep the root end, which contains most of the compound that makes your eyes water, as intact as possible) to the silly (chop with a piece of bread in your mouth, or wear special goggles). What's your best anti-onion-crying technique?

Dicing
When you're stumped for what to make for dinner, dicing an onion is never a bad place to start: by the time you're done, you're likely to have an idea about whether it'll be soup, a frittata, or anything else. Sharpen your best knife -- a sharp knife is actually less dangerous than a dull one, which you can easily lose control of -- and let's get started.


1. Peel and Prep - First things first: halve the onion through the root and tail ends. Chop off that tail end and discard, then remove all traces of papery skin.


2. Cut Horizontally - Being careful not to cut your hands, make 2-3 horizontal cuts through the onion, stopping before you reach the root -- again, a very sharp knife helps with this! What's the point of this step? You're cutting through the curvature of the onion's surface, making for evenly square pieces of onion when you finish.


3(a). Cut Vertically - Cutting from the just before the root to the tail end, make 5-6 straight cuts perpendicular to the horizontal ones. (Don't worry too much if slices on the side start to fall off because your cuts are too deep -- hold them together with your fingers and keep going.)


3(b). Cut Radially - Our Senior Editor Kristen's brother, Billy, prefers radial cuts when dicing his onions -- ie, angling along with the curve of the onion, which he claims makes for a finer dice afterward. We tried it and found the results to be more or less the same, but it certainly doesn't hurt to get geometry involved!


4. Ready to Go - After being cut every which way, this onion is ready for its final destiny.


5. Cutting Away - Starting at the tail and moving toward the root, cut across the onion to make tiny, evenly-sized pieces of onion: a true dice. (I look like I'm about to cut my fingers off in that first photo. Rest assured that I still have all 10 of them.)


6. Roll the Dice - Discard the root, and that's it -- saute-ready diced onions.

Slicing, Version 1
There are two ways to slice an onion. The first is easiest, and it's what you look to when pickling onions, topping a pizza, or slicing up chili garnishes. The first steps are the same: halve the onion, cut off the tail end, and peel it.


This is what happens when you skip everything about dicing an onion except that last step: even half-moons of onion that you can easily break up into semicircles from big to small.

Slicing, Version 2
When you're looking to caramelize a batch of onions -- to top mashed potatoes, garnish polenta, or make classic French onion soup -- you should slice a little differently. The method above produces unevenly-sized slices, which means that after 30+ minutes of slow caramelization, some of those slices will have entirely dissolved while others will still have their shape. For even cooking, it's best to slice a little differently: just turn your onion 90 degrees before going at it.


For this preparation, you'll want to cut off the root end of your onion as well when prepping it. Then with the root and tail parallel to your knife, start at one side and start slicing away.


See? Same-sized slices ready for a long, slow session in the skillet.

Coarsely Chopping
Sometimes it can be helpful to have large, evenly-sized pieces of onion: when making kebabs to thread onto bamboo skewers, for instance, or when making chicken stock to extract as much from the vegetable as possible. We saved the easiest preparation for last!


Take everything we said about slicing vertically and horizontally and toss it out the window: after halving and trimming the onion, make 3-4 cuts from root to tail, then 3-4 cuts from side to side. You're done!

Jump to Comments (23)

Tags: kitchen confidence, onions, chopping, how to, how-to & diy

Comments (23)

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7 months ago chris

There are two methods I like for slicing onions without tears. One is to place as much distance as possible between the onion and my eyes by cutting the onion on a low surface, such as a dining table versus a counter top.
The second method is to place the onion to be cut on a cutting board. Use a cutting board with slots for draining water. Next run a small drizzle of water over the onion while cutting. This works best. Do not allow the water to run too fast or your cutting board may not drain fast enough and you will have a bit of a flood. Happy onion cutting !

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about 1 year ago Rod

wowwwwwwwwwwwwww I am surprised you still have 10 fingers.... I hope you are not a qualified chef... if so who taught you that

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over 1 year ago Abby

I'd suggest a embedded video next time - much more useful, and elegant presentation. Unless your objective is to take up visual space, which this certainly does. Also, is your market people who have never cooked before? Cutting onions...really? Okay, if you say so, but I'd make put this under a tab called Kitchen Basics so you don't bore a more experienced audience. I like the concept of the website, but the content is lacking.

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over 1 year ago Jonathan Hoag

Best onion tear prevention?
First and easiest, use a sharp knife. It damages fewer cells, so less of the offending gas is produced, so there are less tears.
You should also ventilate the kitchen. You should do that anyway to handle the inevitable occasional smoke in there.
Also sweet onions produce far less of the offending gas, and they caramelize easily, if that's what you're looking for.

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over 1 year ago Jonathan Hoag

None of these is the best and easiest approach. With one simple method (not gadget), you can have a mince, thin strips (julienne) or evenly cut dice. With ease.
As with these others, begin with peeling. Then trim away any green or brown at the top. Cut away most of the root, but leave the very bottom intact. It will make cutting easier.
Slice the onion in half from the top/green end to the bottom/root end.
Here's the cool part. Take one half and slice it lengthwise, radially.
Is that confusing? Make several slices from the outside towards the center.
To be more specific, lay your knife almost horizontally at just above your cutting board, and slice the onion from the round outer peel side towards the core. Try to make this slice, and every slice until you've gone all the way around, reach all the way to the center of the core.
So from here you would turn your knife a little bit towards vertical, and make another slice to the core.
With just a little practice, you will be able to slice one half or one quarter of an onion like this easily, depending on the size of your hands and the size of the onion.
At this point you have thick or thin slices, depending on how you cut. You tried to make them even, how'd you do? It's up to you and what you want from this onion. Do you want big slices to cook with liver? Or do you want a fine mince for topping a fish taco (use purple for this)?
Anyway, onions are great, and if you now just cut crossways, your slices become a dice.
This method is really easy. People will be impressed with your knife skills.
You can apply a very similar method to carrots, celery, potatoes, anything.

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over 1 year ago Peter Jacobson

I have found keeping onions in the fridge reduces the amount of gaseous compounds released, tears are a thing of the past if you get the job done fast !

Stringio

over 1 year ago Henry Balfour

Your finger postioning is dangerous - you appear to realise this. Curl your fingertips in under the length of the finger, and use the broad width of that santoku to butt up against the shortened fingers .... raise and lower the santoku against the 'fence' of the fingers. The way I see your fingers here, it's only a matter of time until one gets nicked, or worse. As for tears ..... just keep working, they don't hurt and they don't last long.

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over 1 year ago max havoc

No joke, I wear my scuba mask. , yes with the snorkel but I don't use it. Looks ridiculous and works.

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over 1 year ago judy harless

When I cut up onion I strike a match blow it out and put it between your teeth. I buy the long kitchen matches.

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almost 2 years ago BlueLineGal

Best anti-onion-crying technique? I've found that breathing through the mouth (and not through the nose) while chopping prevents watery eyes. Perhaps because you inhale more of the onion's gases through the mouth (versus nose) before they reach your eyes or inhaling through the nose draws the gas closer to the eyes, thus creating more irritation.

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about 2 years ago Pegeen

Pegeen is a trusted home cook.

Goggles, for sure (or an old pair of sunglasses). I've tried everything else except contact lenses.

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about 2 years ago AntoniaJames

AntoniaJames is a trusted source on Bread/Baking.

I've worn contact lenses since I was in my early twenties and have not cried while working with onions since. It's one of the few advantages of being nearly blind. (Actually, I can't think of any others . . . ) ;o)

Gator_cake

about 2 years ago hardlikearmour

hardlikearmour is a trusted home cook.

Contacts are awesome for cutting onions. If I'm wearing my glasses I will light a couple of short candles and try to keep them between the onions and my tear ducts. It definitely helps but is not nearly as effective as wearing contacts.

Noz_photo

about 2 years ago nzle

I've always found the opposite to be true -- when I wear contacts, I not only have teary, painful eyes, but also the added pain of contact lenses irritating my eyeballs!

Cakes

about 2 years ago Bevi

Is there any truth to "the sharper the knife, the less you cry"?

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about 2 years ago davidpdx

Probably. A Sharp knife slices the onion cells cleanly, leaving more of the sulfuric compounds inside the cells; a dull knife crushes the cells, exposing more of their contents to the air and, hence, to your eyes. In addition, I think Cooks Illustrated assessed that the Slicing, Version 2 above (longitudinally) results in fewer damaged onion cells and fewer tears.

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about 2 years ago Pegeen

Pegeen is a trusted home cook.

Very clear and accurate instructions. Thank you! I'm on it with the onions, but often must explain some basic techniques to less experienced personnel (nieces, nephews, neighbor's kids). This great link will be added to my Evernote "how to cook" notebook. (Now there's a category to add to the site - features related to basic cooking techniques. Not that you haven't been thinking about that.)

Regarding onion tears: In the magnificent film "Like Water for Chocolate," Tita shows us how to cope: simply wear a slice of onion on top of your head while chopping one. (Personally, I like wearing the root end - it gives a little height, like a chic top knot.) That and sunglasses... well now we're in an Italian film.

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about 2 years ago nzle

I'm so glad you found this helpful! And I like your chic top knot idea.

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about 2 years ago aargersi

Abbie is a trusted source on General Cooking.

You forgot a step - log on to Amazon and buy goggles! They rule. You can also wear a dive mask.

Kandm

about 2 years ago Kristy Mucci

Kristy is an expert at making things pretty and a former Associate Editor of Food52.

I've heard that goggles are the only things that really work! I've also heard that cutting an onion by an open flame is effective, but I've never tried it.

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about 2 years ago aargersi

Abbie is a trusted source on General Cooking.

I just realized that the goggles ARE referenced above - seriously they are the only thing I have found that works. I also wear them when grilling / smoking to keep my eyes functional. Fly your dork flag proudly!!!!!

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about 2 years ago hardlikearmour

hardlikearmour is a trusted home cook.

The open flame does work pretty well, but really only if it's between your eyes and the onions, so it does require a little extra care!

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about 2 years ago nzle

Between your eyes and the onions -- now it makes sense! I basically always have a pot on the stove going when I'm chopping onions and my counter is right next to the stove, so I've always wondered why the trick didn't work. Maybe I'll get a tall candlestick and try my luck.