As a home cook, one of the best skills to learn is how to cut an onion properly. Tons of recipes call for the savory ingredient so it’s worth learning exactly how to chop and dice it up.
There are also many different types of onions like yellow onion, red onion, white onion, and sweet onion. Each type has its own unique flavor profile making them perfect for a variety of dishes.
Once you learn the basics of how to hold and properly cut an onion, you’ll be able to get different cuts like slices, diced, and other essential recipe shapes.
Safety Reminders
Use a sharp and honed knife: Because the onion is essentially a circle shape, you’ll need to make sure the knife you’re using is sharp and honed so you can properly cut it.
Where to cut on the blade: When you’re using a chef’s knife, the sharpest part is going to be right in the middle, maybe 3 or 4 inches from the tip. You always want to start your cuts at the center of the knife and move toward the tip to make clean and easy cuts.
Protect your fingers: Make sure that you are always using a cut-resistance glove when you are chopping or slicing your onions. This will help protect your fingers from any accidents that might occur while you are cutting.
Take Off the Ends
Using your knife, cut off about a 1/2 inch of the stem
If you are making sliced onion, cut just past the root end
If you are making diced onions, cut the root end while keeping the bulb intact.
Cut Your Onion In Half
Place the onion on the flat part you just cut. Cut the onion lengthwise down the middle so that you create two halves.
Chef’s Tip: If you immediately place the cut sides down they won’t release as much sulfur and cause you to tear up.
Peel Off the Skin
Using your fingers, peel away all the skin and papery layers. You might have to remove the first layer of the onion.
Slicing Your Onion (2 Methods)
Option 1) Cut Lengthwise: Cut the onion right down the middle following the grain. The onion will be more sturdy using this method. You’ll also have a milder flavor if you cut with the grain.
Option 2) Cut Crosswise: Cutting against the grain on an onion gives you arched pieces that have a stronger flavor. You are causing more sulfur compounds to be released. The onion pieces will also be more vulnerable because the fibers are cut.
Making Onion Wedges
Make sure not to cut the root end with this method so the onion layers stay together. Cut the onion in half lengthwise and place them cut-side down. Make radial cuts along the onion to produce wedge shapes.
Making Onion Rings
Cut off your root end about 1/2 inch and cut the stem about 1/2 inch using your knife skills. Cut the onion in half right through the middle. Place the onion on your cutting board with the middle-cut side down. Now, make cuts crosswise and you’ll create rings to your desired thickness.
Dicing Your Onions (3 Methods)
Option 1) Traditional Method: Cut your onion horizontally, parallel to your cutting board. Cut about 1 to 3 times but don’t cut through the root end.
Then, make vertical cuts starting at about 1/2 inch from the root end. You can determine how thick you want your diced onions to be. Make perpendicular cuts to create the diced onion.
Option 2) Angled Method: Make lengthwise cuts that are at about a 60-degree radial angle. You don’t want to cut through the center. Then, make perpendicular cuts to your desired size.
Option 3) Vertical Method: If you don’t like making horizontal cuts, you can start by cutting the onion in half. Then, cut the middle again to make four pieces. Working with each piece separately, make vertical cuts and flip them over onto the sides.
Continue making vertical cuts on the sides facing up. Slice onion horizontally to create your diced onion pieces.
Dicing vs. Chopping
Dicing your onion makes more uniform pieces and they all look like little square onions. If you want to make stews, soups, or stir-fries, this method is best.
Chopping your onion is slightly different and not all the pieces are uniform. You won’t care about how the onion pieces look with this method because the onion pieces usually go in a recipe like meatloaf or meatballs.
Diced Onion Terms
Minced: Smallest cuts you can make
Chopped Fine: Slightly larger cuts of onion, about 1/8 to 1/4 inch thick
Chopped Medium: About 1/4 to 1/2 inch thick
Chopped Coarse: About 1/2 to 3/4 inch thick pieces
Why Do Onions Make You Cry?
Onions are full of sulfur-containing compounds. When the knife breaks the cells in your chopped onion, it causes those compounds to mix together and release a gas that irritates the eyes.
If the onion is left uncut, there won’t be hardly any aroma or smells that emanate. The enzyme causing this distress is alliinase and it reacts with isoallin to make the common tear-causing sulfur compound.
The more you cut the onions the more they will make you cry. This is also true the longer you keep the onion out after it has been cut.
How to Cut an Onion Without Crying
Use a sharp knife: A sharper knife helps to make cleaner cuts and you won’t damage as much of the cell wall of the onion.
Wear eye protection: Any eye protection will help the sulfur from reaching your eyes. Contacts are great but even protective goggles will work.
Turn on a vent: Turn on your stove vent while cutting onions so the sulfur compounds get sucked away.
Leave the root end intact: More sulfuric compounds are concentrated in the root end of your onion. If you leave this part intact or cut it off altogether, you’ll have less eye irritation.
Cover the cuts: Limit your exposure by keeping the cut sides of your onion facing down on your cutting board.
Chill it: Putting your cut pieces in the fridge slows the process of enzymes breaking down. You can keep the onion in the fridge for about 30 minutes or freeze it for up to 15 to 45 minutes.
Choosing Your Onion
A mild onion will be filled with more water and, as a result, be softer, have thin skin, and have broader necks. A smelly onion will be dry, heavy, and firm.
Storing Your Onion
You want to ideally use your onions within about 7 to 10 days if you store onion in an airtight container in the fridge. A resealable bag will also work but if you were to stick the bag in a container then your onions won’t stink up your fridge.
You can also freeze your onions for up to 6 months and you don’t even need to defrost them.
Different Ways to Use an Onion
French onion soup
In meatballs
Caramelize them for toppings
In stews or soups
FAQ
Which end of onion do you cut off first?
You always want to start with the stem side so that you have a sturdy base to place your onion down on.
Should you remove the center of an onion?
The center of the onion is where a lot of flavors are because of all the flavor precursors. It may add more flavors to your dish if used but it can be strong for some people.
Does the way you slice an onion affect the taste?
Absolutely, since all the sulfur compounds are stored in the onion walls, the more you slice it the more flavors and pungency will be released. So if you want a milder taste, use a sharp knife that makes clean cuts.
Soaking Your Onion in Water
When you are done dicing or slicing your onion you can soak it in water for up to 15 minutes. This method helps to get rid of some of the sulfur compounds that are being released. The water also creates a slight protection from the enzymes and helps the activity decrease.
How To Cut An Onion (Multiple Methods)
Learn the best ways to cut an onion in this easy-to-follow step-by-step guide. You'll get multiple methods and never have to cry from an onion again!
For Slices – Starting lengthwise, slide your onion all the way from the root to the end. Follow the grain of your onion to get a milder flavor. For stronger flavors, cut crosswise against the grain and repeat the process with the other onion half.
For Wedges – You'll start by making radial cuts that are toward the center of the onion. This will produce a wedge shape. You can make 2 to 3 cuts for larger pieces and 3 to 4 cuts for medium-sized pieces. It will take about 4 to 5 cuts for smaller pieces.
For Rings – Cut the onion lengthwise down the middle about 1/4 inch slice. Put the cut-side on the board and then make crosswise cuts through the equator of your onion.
To Dice an Onion
Traditional Method – Cut the onion in half. Make horizontal cut about 1 to 3 of them horizontally towards the root end. Don't cut all the way through. Then, make vertical cuts lengthwise until about 1 inch from the root end. Rotate your onion so the root end is now facing the back. Now, make perpendicular slices that create a diced onion.
Angled Method – Make lengthwise cuts on a halved onion that are about 60-degree radial cuts. Make sure they are not in the center. Then, make perpendicular cuts to your desired sized.
Vertical Method – Create quarter pieces of your onion but cutting it in half and then cutting in half again. Then, work on each piece separately and start making vertical cuts about 1 inch from the root end. Flip the onion so the cuts are horizontal. Then, make vertical cuts again about 1 inch from the root end with the sides that are facing up. Push your two quarters together and slice horizontally to create the diced onion pieces.
Notes
Yield: A 2" wide onion will produce about 1/2 cup. A 3" wide onion will produce about 1 cup. A 4" wide onion will produce about 2 cups.Diced Sizes: Minced onions are about 1/8 thick or smaller. Fine onions are about 1/8 to 1/4 inch thick. Medium-cut onions about 1/4 to 1/2 inch thick. Coarse onions are 1/2 to 3/4 inch thick.Storing: Place your cut onion pieces in an airtight container or a resealable bag. You can even place your bag in an airtight container for better preservation. Refrigerate them for up to 7 to 10 days or freeze them for up to 6 months.
