How to cut an onion properly

I've received many questions about how to cut an onion, and I wanted to share my method with you. There are many ways to cut an onion properly, and I even discovered some new techniques in my recent research. However, I will share the method I learned in culinary school, which is great for home cooks. (Video tutorial at the bottom of the post!)

It might take some practice to get it right, but when we're cooking them down and eating them up, why stress over it?! Bonus: this is a great way to get started organizing your cooking process for a more successful outcome! Let's start with a little information about onions.

Jump to:

• Types of slicing onions
• Don't cry about it
• Tools for the job
• How to cut onions properly - two ways
• Video tutorial for dicing and slicing onions
• Practice this how-to with these recipes
• 💬 Comments

Types of slicing onions

Here are a few of the most common types of onions found at the grocery store.

• Yellow onion - It has brown, thicker, papery skins and it's white on the inside. Round in shape, it ranges in size from a lemon to a large softball. It is the least expensive and most commonly found and used onion.
• White onion - These onions have white papery skins and are also white on the inside. They are less pungent than yellow onions. They are good for raw onion applications and cook well, too.
• Red onion - This type of onion has dark reddish-purple skins and is purple and white on the inside. It is good for raw onion applications, but it can take over the flavor of a dish if you're not careful. Hint: Soak cut onions in water for 10+ minutes before using.
• Sweet onion - This onion is light-colored, with thin, flakey skin and a sweet flavor. Its shape is less round than that of other onions. Hello, onion rings! These are great raw or cooked.
• Shallot - A teardrop-shaped vegetable with pinkish brown thin skin and white and purple inside; it is commonly minced and added to a cooked recipe along with garlic or as a garlic substitute. It is also nice added to cold salads and fantastic fried and frizzled. It is milder than a red onion but similar in flavor.

Don't cry about it

We all know this happens, and most of us have experienced the pain through the process. Whether you cut an onion properly or not, avoiding the onion tears is hard!

• Use a sharp knife (paid link) - This helps by not only getting the job done faster but it prevents "smashing" the onion as you chop it, which releases more of that pesky compound.
• Cover your eyes - No, not completely! Though I've been known to cut with my eyes closed due to so much pain after 8, 9, 10 onions later. (Serious knife skills required!) But really, I hear wearing contacts helps, as well as onion goggles.
• Old wives tales - Some say holding a matchstick between your teeth, tip side out, works. I've had luck a few times chewing gum. I'm not going to explain why these work because they really are old wives' tales. But I'm always down to try something new, and gum has worked for me in the past.
• Refrigerate or freeze the onion before cutting - I have had better luck slicing refrigerated onions and recently read that freezing an onion for 10 minutes before cutting also works. I believe what is happening is the onion is a bit dryer after the cold air. You'll notice less white milky substance while cutting. Therefore, fewer enzymes/acids.
• Breathe through your mouth while chopping - This is Mom's suggestion! And probably the easiest to implement. Try it out, what do you have to lose??

Tools for the job

• Cutting board
• Sharp knife (paid link)

How to cut onions properly - two ways

Here are the two most common ways to cut an onion: diced or sliced (julienned).

Diced onions

• Start out by slicing off the root end and tip. Then, slicing from pole to pole, go right down the middle.
• Lay the onion cut side down with the root end facing away. With one hand formed like you're holding a lime, palm side down, set your fingertips onto the onion with your middle knuckle protruding the farthest. This is your stabilizing hand.
• Starting on one side of the onion, touch the tip of the knife almost to the root end, but not all the way. For balance, the flat side of the knife may touch your middle knuckle. Then, slice it down into the cutting board. Pull the knife out and move it slightly over to do this again. Repeat these motions until the onion is in several strips still attached at the root.
• Then, turn the onion slightly so your knife can cut across the strips to create diced cuts. This will create a nice pile of acceptable pieces for cooking.
• OPTIONAL: If you want a bit more perfection, add one or two horizontal slices before step four. To do this, hold the knife parallel to the cutting board. Hold the onion down from the top with your stabilizing hand and watch where the knife will end up after slicing so you don't get your fingertips. Pull the knife through the onion horizontally halfway down from the top. Be careful not to go through the root. Do this twice for a larger onion.
• Proceed with slicing across the strips using your stabilizing hand to hold the onion strips in place while cutting.

Julienned (sliced thin)

• Start out by cutting off the root end and tip. Then, slicing from pole to pole, chop it right through the middle.
• Lay the onion cut side down with one of the ends in front and the other facing away. With one hand formed like you're palming a small ball, palm side down, set your fingertips onto the onion with your middle knuckle protruding out the farthest. This is your stabilizing hand.
• Set the middle of the knife blade onto the very end of the curve of the onion and slice down into the onion towards the cutting board.
• Move your stabilizing hand over just slightly and bring the knife with it, touching the side of the blade to your middle knuckle, and slice again. Continue to work your way across until the entire onion has been thinly sliced.
• Julienned slices are best for caramelized onions.

Video tutorial for dicing and slicing onions

Here's a quick look at how to do the steps above to properly cut an onion!

Practice this how-to with these recipes

Here are a few opportunities to dice and slice your way to success!