We humans have a complicated relationship with onions. On one hand, we enjoy their sweet caramelized flavor in soups and on burgers; we appreciate the crisp bite they add to salads and sandwiches; and we crave the melt-in-your mouth fried onion ring. But ask someone to cut one up and the fight-or-flight instinct kicks in.

The fact that the technique of cutting an onion is unknown to so many, combined with the inevitable tears that follow (both because of the onion fumes and the existential stress factor), seems to leave people in a state of “I’ll buy the pre-cut at Trader Joe’s.” Please fight this urge, I’m here to help.

ONIONS: MYTH OR LEGEND?

The onion is one of the oldest cultivated vegetables, with evidence dating back to 5,000 years. It’s believed to have originated in Central Asia—specifically in today’s Iran or Pakistan. Archaeological findings suggest that civilizations such as Egypt, Mesopotamia and India were using onions not only as flavor but also for medicinal purposes. Onions are a hardy root and can grow in a variety of climates, making them a staple in early agriculture.

Onions have also figured into mythology and folklore through time. In ancient Egypt, onions were considered symbols of immortality and eternity. Their layered structure was seen as a representation of the cycles of life, death and rebirth. Onions were often placed in tombs and burial sites as offerings, with the presumed belief that they would provide protection or spiritual benefits in the afterlife. In folklore, onions have been attributed with various health benefits, including warding off evil spirits, curing ailments and promoting fertility (bad breath not withstanding). They were also regarded as a talisman against bad luck in various cultures.

Onions are a well-traveled staple; in fact, they are found across nearly every continent. They traveled through migration to become a part of global cuisine. The ancient Greeks and Romans brought onions across Europe, and they became integral in Mediterranean cooking. With European colonization, the vegetable spread to the Americas, where it quickly adapted to our agricultural conditions. Today we find the onion as part of French onion soups, Indian curries and Mexican salsas. It’s a vegetable that seems to make friends wherever it lands.

IT’S CHEMICAL

So, why are onions friends when we cook them but foes when we cut them? Well, we cry due to a chemical reaction. Onions contain a sulfur compound called propanethial S-oxide. When we cut through the body of an onion, we break its cells open, releasing an enzyme called alliinase. Long story short, these enzymes convert the sulfur into a gas that evaporates into the air and reaches your eyes. When it meets the moisture in your eyes the sulfuric acid causes irritation, which triggers your eyes to produce tears in an attempt to flush out the irritant.

How do we prevent this? Folks, I’ve seen it all. I’ve seen a prep cook sitting in the walk-in refrigerator wearing a pair of goggles and a grin. He was half right. Eye protection is a good idea, but during a family holiday I’m sure we don’t want to be photographed wearing swim or ski goggles, unless that’s the legacy you want to leave.

Ultimately, there is no sure-fire way to prevent this chemical reaction. A very sharp knife will cut more cleanly and damage fewer cells in the onion, thus decreasing the chemical conversion. Contact lenses seem to help, in my experience, but I’m not sure I can back that up with empirical evidence. At the end of the day, try to have a sharp knife and a window open with good ventilation. If you do end up tearing up, walk away (outside is best). And if you’ve been wanting to vent some emotions or expletives, now would be a good time.

THE RIGHT ONION FOR THE JOB

There are several common varieties of onions, each with its own unique flavor, color and use in cooking. Here are the most popular ones:

YELLOW ONIONS

Flavor: Strong and pungent. Flavor mellows and sweetens when cooked.

Uses: Most common onion for cooking. Ideal for sautéing, caramelizing and adding depth to soups, stews and sauces.

RED ONIONS

Flavor: Milder and sweeter than yellow onions when raw, with a bit of a sharp bite.

Uses: Great for salads, sandwiches or grilling. They’re often used raw in recipes because of their color and mild taste but can also be roasted or caramelized.

WHITE ONIONS

Flavor: Slightly milder and more crisp than yellow onions, with a sharper bite.

Uses: Often used in Mexican and Southwestern cuisines, ideal raw for fresh salsas, guacamole and salads, but also good for cooking.

SWEET ONIONS
(Vidalia, Walla Walla, Maui)

Flavor: As the name suggests, sweet onions are much milder and sweeter compared to other types. They have a high water content.

Uses: Perfect for raw dishes, such as salads or sandwiches, as well as caramelizing for a sweeter flavor. They’re also ideal for making onion rings.

SHALLOTS

Flavor: Mild, delicate and slightly sweet flavor, with a hint of garlic.

Uses: Common in French cuisine, shallots are often used in dressings, sauces and vinaigrettes or finely minced in dishes where a subtler onion flavor is preferred.

GREEN ONIONS
(aka scallions)

Flavor: Mild, fresh flavor with a bit of sharpness from the white part and a mild sweetness from the green tops.

Uses: Commonly used as a garnish, in salads and in stir-fries. They’re also great for adding a fresh, crunchy element to soups and tacos.

SPRING ONIONS
(immmature yellow, white, or red onions picked in the spring)

Flavor: Slightly sweeter and milder than regular onions, with a more rounded flavor.

Uses: They are often used raw in salads or as a garnish, but can also be grilled or roasted.

HOW TO SELECT A FRESH AND FLAVORFUL ONION

Look for Firmness: Gently squeeze the onion to make sure it feels solid with no soft spots or squishy areas. Softness may indicate an old onion that is starting to spoil.

Check the Skin: The outer skin should be dry, papery and free of wrinkles. Avoid onions with visible bruises, blemishes or sprouts. The skin should be intact without any large, moist areas, which could signal rot.

Choose a Uniform Shape: Opt for an onion with a nice round shape. Bulging or unevenly shaped onions might indicate internal problems.

Color: Depending on the type of onion, the color should be vibrant. Yellow onions should have a golden-brown skin; red onions should have a deep purple skin; and white onions should have a pale, papery white skin.

Smell: Fresh onions should have a mild, slightly sweet aroma. If they smell strong or unpleasant, they could be overripe.

Weight: The onion should feel heavy for its size, indicating it’s still fresh and full of moisture. Light onions may be dried out.

ONION CUTTING TIPS

Set up your workspace with a sharp chef’s knife and a cutting board.

PEEL THE ONION

• Cut off the top (stem end), leaving the root end intact.
• Place on the cutting board with the flat cut side down.
• Cut a small slit into the outer skin along the side and peel off the papery skin layers.

TRIM THE ROOT

• After peeling, you’ll see the root end of the onion, which is the part that holds the layers together.
• Leaving the root end intact will make the cutting process easier.

CUT THE ONION IN HALF

• Place the onion flat side down.
• Slice the onion in half vertically from the top to the root end.

MAKE HORIZONTAL CUTS

• Take one half of the onion and place it flat side down.
• Hold the onion steady and, with your knife parallel to the cutting board, make a series of horizontal cuts. Depending on how fine you want the onion pieces, you make 1–3 horizontal cuts.
• Do not cut all the way through the root end; this keeps the onion layers intact.

MAKE VERTICAL CUTS

• Rotate the onion 90° so the root end faces you.
• Slice vertically from top to root, creating evenly spaced cuts. These will determine the size of your diced pieces.

DICE THE ONION

• Finally, hold the onion together and slice across the vertical cuts. This will create diced onion pieces.
• Continue slicing until you reach the root end.
• Discard the root
• Once you’ve finished dicing,discard the root end, as it tends to be tough and fibrous.

COOKED TO PERFECTION

Sautéed onions add flavor to many dishes. Heat some butter or oil in a pan, add the onions and stir occasionally until they become fragrant but have not started to brown. You can also give them a taste. There shouldn’t be any crunch; if there is, lower the heat and cook longer.

To caramelize the onions, continue to sauté, adding a tablespoon of water every now and again to deglaze the bottom of the pan and transfer that beautiful fond, or crust, into the onions.

If you’re thinking about using onions raw, consider using red or white onions but rinse them in fresh water after cutting to help ease the bite from the juice left from the cut. Green onions or shallots work very well for garnishes and don’t require the rinse.

A simple roasted onion is a joy. Cut the onion in quarters or in rings and place on a roasting pan with oil and salt. Roast at 350°F until soft and lightly caramelized. For a grilled onion repeat these steps but instead of allowing it to finish in the oven, transfer to a high-heat grill and let cook until soft and charred to your liking.

A FRIEND INDEED

If we can get past the part where onions make us cry every now and again, they have a lot to offer.

Rich in Nutrients: Onions are low in calories but high in vitamins and minerals. They are a good source of vitamin C, vitamin B6, folate and potassium.

Antioxidant Properties: Onions are packed with antioxidants, such as quercetin and sulfur compounds, which help fight oxidative stress in the body, potentially reducing the risk of chronic diseases.

Anti-Inflammatory Effects: Compounds in onions may help reduce inflammation, which can be beneficial for conditions like arthritis and other inflammatory diseases.

Support Heart Health: Onions may help lower blood pressure and reduce cholesterol levels due to their high levels of antioxidants and sulfur compounds. Regular onion consumption can contribute to better cardiovascular health.

Boost Immune System: Due to their vitamin C content, onions help strengthen the immune system and may assist in fighting off common illnesses like colds and flu.

Improve Digestive Health: Onions contain prebiotics, particularly inulin, which promotes the growth of beneficial gut bacteria and supports digestive health.

Blood Sugar Regulation: Some studies suggest that onions may help regulate blood sugar levels, which could be beneficial for people with diabetes or those at risk of developing it.

Promote Bone Health: Onions may help improve bone density and reduce the risk of fractures due to their high levels of antioxidants and sulfur compounds.

Antimicrobial Properties: Compounds in onions may help fight bacteria and viruses, potentially aiding in the prevention of infections.

May Have Cancer-Fighting Properties: Some studies suggest that the sulfur compounds and antioxidants found in onions may play a role in reducing the risk of certain cancers by inhibiting the growth of cancer cells.