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Onions: Are You Supposed to Wash Them?

They say an onion a day keeps the doctor away. But that’s only true if you wash and handle it right.

Onions are one of the most versatile foods you can buy in the produce aisle of the grocery store. Whether sliced, chopped, or diced, they can be eaten in soup, caramelized and added to salads, breaded and fried into onion rings, or used as a tangy topping for burgers.

But a question arises, and it’s of the kind that TV chefs and cookbook authors fail to answer in their shows and recipes: Are you supposed to wash the onions and, if so, when?

At the store, look for whole onions with a firm bulb and dry skin. The roots should be free from mold, and the stem shouldn’t be sprouting. An off odor, excess mushiness, and brown spotting are all signs of spoilage.

At home, store onions at room temperature and in a cool and dark place, such as your pantry, the basement, or a root cellar. Areas lit by sun, like a windowsill, should be avoided.

Since dirt can harbor bacteria, it is important that you wash whole onions before peeling and cutting them. Run lukewarm water over the onions and scrub them with your hands, removing any visible dirt.

Despite lore to the contrary, all you need is lukewarm water and your hands. A brush is not only excessive, but can damage the surface of the onion. Produce should never be washed with soap or detergent, as, according to the USDA, the residue can give the onion a bad taste and make you sick.

Place the washed onions on a clean, well-sanitized surface, such as your cutting board. Do not keep them in the sink, which is often dirtier than your toilet, as all the bacteria from raw meat and produce is lurking in the shiny bowl.

Once washed, peel off the papery skin by hand. Set the onion on its side on the cutting board and cut off the roots and stems using a paring knife (in case you don’t have one, a chef’s knife will do).

Halve the onion with your knife and peel off the inner peel by hand. Then slice and voilà, you can eat or cook with it as desired.

Getting Cleanliness Right When It Comes to Produce

Pathogenic bacteria live in the dirt and on the surface of raw meats and uncooked produce. This includes Salmonella, E. coli, and Listeria, which the Centers for Disease Control and Prevention (CDC) says cause a large percentage of food-borne illnesses in the United States.

When you are prepping onions, it is essential to wash off the dirt before you cut them. Otherwise, the blade of your knife will get contaminated with the bacteria and transfer them to the inside of the onion when you cut it.

This is especially true if you’re preparing a salad with raw onion and/or a member of your family has a weakened immune system.

The History of the Onion

The cultivation and eating of onions seem to have originated in Central Asia about 5,000 years ago—though some food historians suggest they may have originated in the area where modern Iran and Pakistan now exist.

In any case, onions were probably harvested wild by hunter-gatherers even before they were cultivated. They showed up all over the world, in Egypt, Biblical Israel, India, Greece, Rome, and even Pre-Columbian America.

The Pilgrims brought the European variety of onion to North America onboard the Mayflower. Onions quickly became a cash crop in New England and, by the early 18th century, were sold as far south as Barbados and Surinam.

The Types of Onions

According to Taste of Home, six different types of onions exist:

Yellow Onions

Yellow onions can be used for just about everything, including as part of sauces or stews, sliced in a sandwich or hamburger, or part of a salad. These types of onions hold up very well in the caramelization process when pan-frying in oil.

Sweet Onions

Sweet onions, especially the Vidalia variety, go very well as part of a salad or as a garnish. The taste is very mild for onion with a pleasing hint of sweetness.

Red Onions

Red onions are great as part of a salad or sliced into a sandwich or hamburger. They have a sharp, peppery taste. Red onions can also be grilled as a side for barbecue meat.

White Onions

White onions are prime ingredients for a potato salad or a macaroni salad. They are also great as part of a number of Tex-Mex dishes, including nachos, fajitas, and tacos. White onions are ingredients for salsa and guacamole.


Shallots are used as ingredients for sauces and salad dressing. They are also used in many French dishes.


Scallions, chives, or green onions can be served raw as a side dish. They are also used in some Mexican and Chinese stir-fry dishes. Scallions tend to taste a bit milder than more conventional onions.

Cooking With Onions

Onions, either raw or cooked, are an important ingredient in a variety of dishes. But what about dishes in which the simple onion is the star? Here are some examples.

French Onion Soup

A site called Simple Recipes has a great recipe for French onion soup. The process is somewhat labor-intensive, requiring caramelizing the onions, a process that takes about 35 to 40 minutes on the stove.

The recipe also suggests using beef stock from a roast, but beef stock can be readily bought at the supermarket. The recipe also involves toasting slices of French baguettes topped with Gruyere and parmesan in the oven.

The cooking process takes about an hour and a half. Use red onions or white onions.

Onion Rings

Onion rings are a favorite side at fast food joints. Most people don’t cook them at home since it requires using a deep fryer and thus the potential, to make a mess.

However, the air fryer represents an opportunity to make onion rings quickly and easily. First, slice the onions and then separate them into rings. Dredge the onions in a mixture of flour, paprika, and salt, dip them in a buttermilk and egg wash, then coat with panko breadcrumbs.

Cook the breaded onions in a single layer in the air fryer at 400°F (200°C) for 11 to 15 minutes. Then extract them with a spatula and serve. You’ll likely have to air fry the onion rings in batches if you have a big crowd to serve, say for a game day.

Sweet Onion Pie

Sweet onion pie is not as familiar to most people as it should be. However, it looks incredibly easy to make, especially when using a premade frozen pie crust that you can get at the store. Cook the pie crust, lined with foil, in the oven for six minutes at 450°F (230°C).

Then allow the pie crust to cool on a wire rack. Meanwhile, you slice a couple of sweet onions and sauté them in butter for 30 minutes. Remove the foil off the pie crust and pour in the onions.

Top the onions with a cup of egg substitute, a cup of fat-free evaporated milk, and season with salt and pepper. Bake at 425°F (220°C) for between 30 and 35 minutes. Let stand for 5 to 10 minutes before cutting slices.

Grilling Onions

Grilled onions make a great side for any barbecue meat, especially considering that you will have your outdoor grill lit anyway. First, peel the onions and either slice them or cut them into wedges.

Brush the onion pieces with olive oil and apply any combination of spices you like. Try a combination of Italian herbs and spices: oregano, basil, rosemary, etc.

Place the onion pieces directly on the grill or, if you fear the onions slipping through the grates, place them in a grilling basket. Grill for five to seven minutes on each side and then serve.

White, yellow, red, or sweet onions work, but for taste and caramelization, sweet Vidalia onions are the best.

Onion Dip

Of course, you can always get onion dip from the store. However, it’s more fun to make some from scratch. Caramelize the onions in olive oil on the stove.

After allowing the onions to cool, mix in the rest of the ingredients, which include sour cream, mayo, kosher salt, white pepper, and garlic powder. Then refrigerate until you’re ready to serve.

Using Onions with Poultry

One great trick for cooking either a whole chicken or a turkey is to stuff an onion in the cavity. After washing the bird inside and out, peel and stem the onion and stuff into the cavity.

Tie the legs together. Roast the bird according to the instructions. The onion’s flavor should permeate into the bird. If you are going to make gravy from the drippings, cut up the onion and add it to the gravy.