Why Does Chopping Onions Make You Cry?

Dicing onions

Onions are a great addition to any recipe since they add to the taste and give wonderful texture. But anyone who has ever worked with onions can attest to what a painful experience it can be. When you are tasked with chopping or dicing them, it is a race against the clock. If you rush it, you might end up cutting yourself and if you go too slow, the inevitable tears start to stream down your face. If you ever wondered why onions have this effect on people, then you are not alone.

Onions, together with many other plants such as garlic that belong to Allium species, absorb sulfur from the soil as they grow. When you cut the juicy edible part of the onions known as scales, you end up breaking cells within it, releasing certain enzymes. Consequently, the released enzymes react with the absorbed sulfur to create amino acid sulfoxides. These, in turn, create a substance known as syn-propanethial-S-oxide that is highly unstable. When this substance, in a gaseous state, gets in contact the moisture present in your eyes, it causes a burning sensation.

Tears in your eyes are normally controlled by lachrymal glands that are positioned just above your eyelids. Once your brain gets a message that there is such an irritant in your eyes, which is causing a burning sensation, it signals the lachrymal glands to secrete tears in order to flush the irritant out of your eyes. However, cooked onions do not produce such an effect since the process of cooking them inactivates the enzymes responsible for making the syn-propanethial-S-oxide. Therefore, you can comfortably chew cooked onions without getting teary-eyed.

Tips To Avoid The Tears

Fortunately, there are several proven ways that will stop onions from watering your eyes as you chop them.

Refrigerate onions for at least 10 to 15 minutes prior to cutting them

By chilling or cooling the onions, the sulfoxides/enzyme reaction rate is slowed down. This, in turn, minimizes production of the syn-propanethial-S-oxide. This process will have zero effect on taste. Alternatively, you can just run water over the onions as you chop them.

Use a super-sharp knife when chopping the onions

The enzymes are usually released when the cells within the onion are crushed or broken. A very sharp knife will slice through the onion instead of crushing and therefore, fewer enzymes are released. In fact, it is recommendable to use a very sharp knife every time you cut onions regardless of the different tactic you want to apply.

Use a food processor

If you buy this appliance for just one cooking task, then cutting onions would be the main benefit. Not only can you avoid knife mishaps and tears, but it will tremendously speed up your food preparation for the most arduous recipes. Anything that involves a lot of slicing, dicing or chopping can great benefit from one of these machines. You can check out reviews of the top food processors and see that they can do a lot more than saving you from the wrath of the onion. These are a godsend to have in the kitchen and well worth the investment for anyone who loves to cook.

Soak the onions in water before cutting them

When you soak the onions in water, you create a water-air boundary which inactivates the enzyme. This tactic is especially helpful for those who do not own a freezer or refrigerator. However, this process may eliminate some flavor and will also make the onion a little more slippery than normal.

Wear a gas-tight mask or onion goggles

You can use onion goggles or even your pair of swimmer’s goggles that perfectly fit your face. Since they are gas-tight it means that the gaseous substance will not get into your eyes.

Cut onions next to a window or a fan

Cutting the onions close to a fan or a window helps pull the gas away from your eyes.

Some of these will work better than others. The top two ways are to chill your onions or to use a food processor. While using goggles might work, you might find the whole idea rather silly.  Onions are quite a popular vegetable, and for good reason. There are ways around the crying that should let you enjoy them even more. Don’t be afraid the next time your recipes call for chopping some onions.