How to Cut an Onion

An onion is a series of petals held together at the root. That root can be very handy as you cut the onion. By leaving as much of it intact as possible, you’ll hold the onion petals together, making them easier to chop. The rule with any round vegetable is to cut a slice off to make a flat surface. Place that flat surface down on the countertop so that the vegetable doesn’t roll around as you’re trying to cut it. 

Hold your knife by the blade between your thumb and the first knuckle of your first finger and wrap your other three fingers around the handle. Choking up on the knife blade like this gives you more control.

It’s important to make precise slices through an onion for a number of reasons. First of all, evenly-sized pieces of onion will cook evenly, which is important to the quality of your finished dish. Secondly, just hacking away at an onion will cause you to cry more. When you cut an onion a series of chemical reactions occur that unleash propanethial S-oxide – an irritant that causes the eyes to fill with tears. Fewer precise cuts will minimize this chemical reaction. To avoid crying when slicing onions, you can try wearing contact lenses, glasses or goggles, turning on your vent hood, placing the cut side of the onion down on the cutting board as much as possible or just cut the onion faster!

Quick Notes:

• Always create a flat side to work with so the onion doesn’t roll around.
• Try to cut an onion into evenly sized pieces so that they cook evenly as well.
• Cutting an onion produces a series of chemical reactions that unleashes propanethial S-oxide, an irritant that causes the eyes to fill with tears. Avoid tears by wearing contact lenses, glasses or goggles, turning on a vent hood, placing the cut side of the onion down on the countertop as much as possible or just cut it faster!
• Leave the peel on if you are only using half – the remaining half will stay fresher that way.
• Store onions at room temperature in a cool, dark place.

How to Cut an Onion