Have you ever looked at a new recipe that called for onions and wondered what kind you should use? Or, have you wondered if one type of onion could be substituted for another without significantly altering the end result of a dish? If you know just a little bit about different types of onions and what their flavor profiles are, you should be able to choose the right onion, or substitute one for another, without having to run to Google for help.

Yellow onions

yellow onion Yellow onions are usually safe bet to use if a recipe doesn't specify which kind of onion to use. (Photo: Thanthip Homs/Shutterstock)
Yellow onions are the workhorse onions of the kitchen. They're usually the kind you find in mesh bag of onions in the grocery store at a reasonable price. Chances are, if you keep one type of onion on hand, it's yellow onions. Why? They are incredibly versatile. According to the National Onion Association, 87 percent of the onions grown in the United States are yellow.

Yellow onions have a bite when eaten raw, but when cooked, they turn mellow and become sweeter. As they are cooked, the softer and more translucent they become and the mellower they get. Yellow onions are great to use for caramelized onions, becoming soft and sweet with low, slow cooking.

If a recipe calls for onions and doesn't specify which type, yellow onions are a safe bet. Use them anytime a recipe calls for the holy trinity of vegetables — or mirepoix as the French call it, which is diced onion, carrot and celery, usually in equal amounts. Use them in these dishes, unless the recipes calls for a different type:

  • Soups
  • Stews
  • Sauces
  • Casseroles
  • Roasted beef, lamb and poultry — put them around or under the meat to add flavor

Red onions

red onion  With their sharp taste, red onions can add lots of flavor but aren't for every recipe. (Photo: Bukhara Yurii/Shutterstock)
Red onions are crisp with a mild flavor but they can become more sharp and pungent with age. There are different varieties of red onion, and some are sweeter than others. Mainstream grocery stores usually don't label the variety of red onion, so it's not always easy to know if you're getting a sweeter or sharper onion.

Many people think red onions are the best to eat raw and the best to grill in slices. They can be used in these dishes, unless the recipe you're using calls for a different type:

  • Guacamole
  • Salads
  • Burgers
  • Sandwiches
  • Ceviche
  • Pizza topping

White onions

white onion Sharper than the yellow onion, the white onion has multiple uses. (Photo: Francesco Messuri/Shutterstock)

White onions are sharper than a yellow onion, and that needs to be taken into consideration when using them. When cooked, they mellow and get sweeter, so they can be used as a substitute for yellow onions, but be aware they may still be a bit more pungent. When raw, they are definitely more pungent than yellow onions and the difference will be more noticeable. Not only with the flavor be different, white onions will be crunchier.

Use them in these dishes, unless the recipe calls for a different type:

  • Mexican food
  • Stir-fry
  • Chutney
  • Potato, pasta or egg salad
  • Salads

Sweet onions

vidalia onion Sweet onions like this Vidalia aren't always distinguishable by the way they look. (Photo: David Dea/Shutterstock)

There are various types of sweet onions. Vidalia, a type grown around Vidalia, Georgia, is the most well-known. Other common varieties include the Sweet Spanish and the Walla Walla. They don't look all that different from yellow onions, but they should be labeled either by their variety type of simply "sweet onions" at the grocery store.

As their name suggests, sweet onions are one of the sweetest types of onions and they have a very mild flavor. They're good raw because of their mildness, and are extra sweet when caramelized. Because they get more sweet as they are cooked, they will add a lot of sweetness to a dish, so if you aren't looking to add sweet, they aren't a good choice. They can be used in these dishes unless the recipes calls for a different type:

  • Battered onion rings
  • Salads
  • Sandwiches
  • Burgers

Green onions and scallions

green onions Green onions are the shoots of onions before the bulb has fully developed. They're mild and versatile. (Photo: sucesso images/Shutterstock)

Green onions and scallions are the same thing. They are onions that have been picked right before the bulb begins to form. Both the green and white parts are used. The darkest green ends have more of a bite than the lighter green parts or the white parts, but the bite isn't harsh. Overall, they're mild and on the sweeter side. They can be eaten raw or cooked.

Green onions/scallions can be used in these dishes unless the recipes calls for a different type:

  • Dips
  • Chinese dishes — stir fries, scallion pancakes, soups
  • Cornbread
  • Salads
  • Baked potato topping
  • Pasta, chicken or egg salad

Shallots

shallots Shallots are a type of onion that have cloves, like garlic, and have a mild flavor. (Photo: Nares Soumsomboon/Shutterstock)

Shallots taste like mild onions, and some people can taste a little bit of garlic flavor in them. They break apart into cloves. When a recipe calls for a shallot, it means the entire bulb with all of the cloves. They can be used in many dishes that call for onion, but they will be milder than a yellow onion. They're good to use in dishes for people who say they don't like onion, including:

  • Vinaigrette
  • Sautéed with mushroom to put on a steak or burger
  • French foods
  • Deviled eggs
  • Scalloped potatoes

Of course, there's always room for experimentation, so if you want try something like using a red onion in soup, go for it. Maybe make a small batch, though, so if it isn't to your liking you don't waste too much time and food.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.