Onions 101 – About the Different
Types of Onions
Onions are one of the oldest known cultivated vegetables believed to be grown for over 5,000 years. They are a culinary staple in most kitchens. Onions are available in many sizes, shapes, colors, and flavor intensities, with each type having its own unique uses in food preparation. Onions are members of the allium family, a group of pungent plants that includes literally hundreds of species. Besides onions, this plant family also includes garlic, leeks, chives, ramps, and many other such foods. Each member has its own special characteristics. This article covers helpful information about the most common types of onions that you may find in your local grocery stores and farmers’ markets.
Storage onions are those that have been cured (laid out to dry) after being harvested. They can be kept fresh for months when stored properly. According to the National Onion Association, the best way to keep storage onions is in a cool, dry, dark and well-ventilated room, such as a pantry, cellar, basement or garage. The ideal temperature is 40-50°F. A dry, cool environment helps to keep them from sprouting or rotting. Ventilation helps to prevent molding and rotting. Avoid keeping them in a plastic bag since the trapped humidity and lack of ventilation will cause them to age faster. An open basket, bamboo steamer, mesh bag, netted bag, or even hung up in old pantyhose will work well for keeping storage onions. Keeping them in darkness also helps them to last longer. The lack of sunlight reduces temperature and humidity changes, which promote onions to age faster. Examples of storage onions include yellow, red, and white onions.
Characteristics. Yellow onions are a type of storage onion. They are sometimes referred to as brown onions because their skin looks light brown after being cured. They are cured after being harvested, and can be kept for months when stored properly. Yellow onions are excellent all-purpose cooking onions. Because of their relatively high starch content, they won’t become overly mushy when cooked for an extended period of time. Yellow onions range in size from small to large. The average, medium size yellow onion is 2 to 3 inches in diameter and weighs about 3.88 ounces (110 grams). Almost all (about 90 percent) of the storage onions grown in the United States are yellow onions.
Flavor. Yellow onions are generally the preferred onion for most applications because their flavor is moderately sharp when raw, being between that of a red onion (sharp flavor) and a white onion (mild flavor). The flavor is sharp when eaten raw, but mellows when cooked. The flavor actually becomes sweet when yellow onions are caramelized.
Best Uses. Since yellow onions are considered to be an all-purpose onion, they can be used any time a recipe calls for onions. If a recipe doesn’t call for a specific type of onion and you’re not sure which onion to use, yellow onions should be your automatic choice. They work exceptionally well in any dish that requires a long cooking time, such as stews, stocks, braises, and soups. They also work well in meat dishes, including roasts. Yellow onions can be used as a substitute for any onion. Yellow onions are the preferred variety for making onion rings, French onion soup, and Bloomin’ onion recipes.
Characteristics. Red onions are storage onions with a red-purple skin with white layers inside, each with a purple coating. They are sometimes referred to as purple onions or salad onions. The richly-colored skin is due to the presence of anthocyanins and flavonoids, which are valuable antioxidants with important health properties. Red onions lose their color when cooked, so many people prefer to use them in raw applications. Red onions make up about ten percent of the onion crop in the United States. Red onions may be used as a substitute for white onions.
Flavor. Resources have conflicting information regarding the flavor of red onions. Some state they have a milder flavor than yellow onions, while other say their flavor is sharper and spicier than that of yellow onions. Personally, I have found both to be true, with some red onions being mild in flavor, while others are extremely sharp. When using a red onion for a raw application, it is advisable to taste a small piece as you are preparing the onion. If the flavor is mild, use it as needed. If the flavor is very sharp and needs some taming for your application, soak it in a bowl of cold water as you’re doing your food preparation. Soaking will help to keep it crisp as you’re working with other foods, and will also tame the flavor making it more tolerable for being eaten raw.
Best Uses. Red onions are most often used in raw foods such as salads and salsas. They may also be sliced and added as a burger or sandwich topping. Red onions may also be pickled and grilled, where their inside will turn into a type of onion jam. Red onions may be cooked, although cooking tends to wash out their rich color, and also diminishes their flavor.
Characteristics. White onions are storage onions that are round, medium to large in size, and with thin, white, papery skins. They have a high water content, so they are very crisp. They are most commonly used in Mexican cuisine. White onions make up about 5 percent of the onion crop in the United States.
Flavor. White onions have a flavor similar to yellow and red onions, that is pungent yet mildly sweet. It has less of a lingering aftertaste than their yellow and red counterparts. If you find you need to tame the flavor, soak them in cold water for up to one hour.
Best Uses. White onions can be used as a substitute for yellow or red onions, both in raw and cooked applications. The texture of white onions makes them a perfect addition to salsas, chutneys, and other raw food applications. They can be diced and added to salads, sauces, guacamole, and wraps. Sliced white onions are excellent on sandwiches and burgers. They can be chopped and added to soups, stews, stocks, and casseroles. They can also be grilled and served with roasted meats, or used as a pizza topping. They are excellent when sauteed, lending an almost sweet-sour flavor to food. White onions pair well with tomatoes, jalapenos, carrots, parsnips, turnips, potatoes, garlic, fennel, meats, poultry, seafood, beans, rice, and herbs such as bay leaves, tarragon, rosemary, marjoram, cilantro, and thyme. They also pair well with spices such as cumin, cinnamon, coriander, anise, and cloves. White onions will keep for one to two months when stored in a cool, dry, and dark place.
Soft onions are more delicate than storage onions. They should be kept (unwashed) in the refrigerator to extend their storage life. Store them in a perforated bag or wrapped in paper towels within a plastic bag in the crisper drawer of the refrigerator. They should be used within 4 to 5 days of purchase. Examples of soft onions include sweet onions, green onions (AKA scallions), and Spring onions.
Characteristics. Sweet onions are medium to large in size. With their light brown papery skin, sweet onions look very much like yellow onions. However, they contain less sulfur and more water than yellow, red, and white onions. Because of that, they are milder and crisper than the storage onions. Sweet onions are usually named for the region where they are grown, such as Washington’s Walla Walla Onions, Georgia’s Vidalia Onions, and Hawaii’s Maui Onions. Such onions are often available only seasonally. They may be used as a substitute for yellow onions.
Flavor. Sweet onions are crisp yet tender, and mild in flavor. They are sweet without the sharpness of the common storage onions.
Best Uses. Sweet onions may be used in both raw and cooked applications. They are excellent when eaten raw on salads or sandwiches, fried into onion rings, or stuffed like you would a mushroom or tomato. They are also excellent when caramelized or used in dishes where onion is the main flavor, such as in onion soup. Sweet onions are excellent when roasted with other vegetables, blended into dressings, dips, and pesto, and roasted with meats. They pair well with basil, mint, cilantro, rosemary, fennel, garlic, chives, tomatoes, citrus fruits, avocado, apples, ginger, meats, seafood, legumes, pasta, cheese, cinnamon, and cloves.
Characteristics. Green onions are also called scallions, bunching onions, and sometimes erroneously called Spring onions. They are small to medium in size and grown in clusters of elongated, straight leaves with narrow, slender bases. The dark green leaves are smooth, stiff, and hollow with small, central tubes. The white base is dense, succulent, and firm with small white roots attached. They are milder and softer than any of the storage onions. Some people believe the white ends are not edible, but they actually are not only edible, but delicious! If you’re a gardener, save the root ends because they will regrow when planted.
Flavor. Green onions are crisp and juicy with a grassy, sweet, slightly pungent flavor. Green onions have a much milder flavor than mature yellow and red onions. Their mild flavor allows them to easily be used in many raw applications. The whiter ends have a stronger, more oniony flavor than the green leaves. Because of the flavor differences, many people will use the green leaves for raw applications and save the white ends for adding to cooked dishes.
Best Uses. Green onions are excellent in both raw and cooked applications. They are delicious when served raw, such as sprinkled on a green salad. They are also often used as a garnish in soups and chili cheese fries. Green onions are often used in Asian and Latin American cooking. Green onions make an excellent addition to any recipe calling for raw onion. Try them in stir-fries, sauteed, roasted, and grilled dishes. Add them to pizza, pasta, casseroles, stews, and curries. Add minced green onions to deviled eggs, savory pancakes, salsa, biscuits, and sandwiches. Green onions pair well with sweet peas, Swiss chard, collard greens, broccoli, snow peas, carrots, radishes, bell peppers, citrus fruits, eggs, meats, and seafood. Green onions will keep for up to five days when wrapped in paper towels within a plastic bag, tucked in the crisper drawer of the refrigerator.
Characteristics. Spring onions are nothing more than very young storage onions. They have small, round globes attached to a straight, layered stalk of overlapping leaves. The bulbs are smooth, firm, crisp, and have colors from white to red hues, depending on the variety. The dark green tubular leaves have a stiff, thick, and crunchy consistency. They are usually harvested early to give the other, nearby bulbs room to grow. As true to their name, they are very seasonal.
Flavor. Spring onions have a sweet, mild, mellow flavor. This is due to the fact that they have not yet developed the gases that are in more mature bulbs. The leaves have a stronger flavor, with herbaceous, pungent, and grassy notes.
Best Uses. Since Spring onions have a fresh, sweet, and subtle flavor, they are excellent for both raw and cooked applications. Both the bulb and leaves are edible, with the leaves having a stronger flavor than the bulb. The onions can be thinly sliced and added to salads, sandwiches, grain bowls, and slaws. They can also be added to soft cheeses, dips, and spreads on appetizer trays. Spring onions are excellent when grilled, roasted, simmered, sauteed, or braised. Spring onions can be a wonderful addition to soups and stews, baked in casseroles, used as a pizza topping, added to stir-fries, cream-based sauces, vinaigrette dressings, and egg dishes. They pair well with asparagus, sweet peas, lettuce, mushrooms, radishes, citrus fruits, potatoes, and meats.
These are simply varieties of onions that are small in size. Store them in a cool, dry, and dark place with good air circulation. Use within one to two months. When cut, store unused pieces, sealed in plastic wrap or an airtight container in the refrigerator. Use cut pieces within four days. Examples of small onions include shallots, Cipolline onions, and pearl onions.
Characteristics. Shallots are small varieties of storage onions. Their size varies from small to large, depending on the variety. They are oblong with a rounded center and tapering ends. The bulbs have dry, papery, thin skin that flakes when touched. Colors range from copper, gold, and pale pink, to red. After being peeled, the interior consists of clusters of cloves, divided into individually wrapped segments, like garlic. Small shallots will average two or three cloves, whereas larger varieties may contain up to six cloves. The semi-dry flesh is off-white to translucent, firm, and dense, with light purple or red rings. Shallots are aromatic with a blend of spicy, sweet, and pungent flavors. They are crisp and not as pungent as yellow onions. The bulbs keep for one month when stored in a cool, dry, and dark place.
Flavor. Shallots have a typical onion flavor, but are not as strong as storage onions. They are very mild and sweet. Shallots can be used any time you don’t want an overpowering onion flavor. When raw, shallots are crisp and astringent. When cooked, they have a delicate, sweet, and savory flavor, reminiscent of garlic.
Best Uses. Since shallots are rather mild in flavor, they can be used both raw and cooked. They can be added raw to salads, bruschetta toppings, and blended into sauces, guacamole, and vinaigrettes. They may also be roasted, pickled, sauteed, cooked with meats or vegetables, added to stews, blended into curries, baked into casseroles, stir-fried with rice, added to pasta, and sliced thin and fried. Shallots may be used in any cooked application and may be used as a substitute for any onion. Also, they can be used as a substitute for garlic, lending a slightly milder and sweeter flavor to the dish. Shallots pair well with beets, tomatoes, mushrooms, green beans, spinach, garlic, capers, meats, fish, cheeses, and herbs such as parsley, thyme, rosemary, tarragon, and mint.
Cipolline (or Cipollini) Onions
Characteristics. Cipolline onions look like small, squatty yellow onions. They are petite and squat, almost like saucers. They have thin, papery skin that adheres tightly to the flesh. To easily remove the skin, quickly place them in boiling water for about 30 seconds, then transfer them to an ice water bath. The skin will be much easier to remove. The firm, juicy flesh of these onions is white and almost translucent. The bulbs will keep up to two months when stored in a cool, dry place.
Flavor. Cipolline onions are sweeter than the larger storage onions. When raw, Cipolline onions have a mild aroma with a semi-sweet, pungent flavor. When cooked, they sweeten and soften into a tender, almost melting texture.
Best Uses. Because of their natural sweetness, Cipolline onions are ideal for both raw and cooked applications. They may be roasted, baked, sauteed, and pickled. Their high sugar content makes them excellent candidates for caramelizing. Add them whole to stews, roasts, and casseroles. They may be chopped and mixed into mushroom tarts, pasta, potato salads, and kabobs. Cipolline onions pair well with balsamic vinegar, mushrooms, chives, green onions, fennel, parsley, thyme, tomatoes, ricotta cheese, parmesan cheese, potatoes, olives, red wine, and cured meats.
Characteristics. Pearl onions are sweet and small, averaging only one to four centimeters in diameter. They are round with slightly pointed ends. They can be found in red, white, and yellow varieties. Pearl onions have a thin, papery skin that flakes off easily. The flesh is firm, juicy, and crisp. The skin is often removed by boiling the whole onion for 2 minutes, then plunging them into ice water, cutting off the ends, then pinching the flesh out from under the skin. Sometimes pearl onions may be found (already peeled) in the freezer section of many grocery stores.
Flavor. The flavor of pearl onions is mild with a savory, sweet, and slightly less pungent flavor than full-sized storage onions when cooked.
Best Uses. Pearl onions are well suited for both raw and cooked applications. They may be creamed, roasted, pickled, and glazed. The small bulbs are commonly used whole. They may be included in stews, gratins, casseroles, braises, soups, stocks, added to meat and vegetable dishes, and even served alone. Pearl onions are an excellent option for being skewered with meats and vegetables and grilled for a caramelized finish. They pair well with parsley, basil, Dijon mustard, potatoes, green beans, peas, beets, turnips, tomatoes, paprika, red wine, mild flavored vinegars, meats, fish, and assorted cheeses.
Julia W. Klee (Judi) began her journey enjoying “all things food” in elementary school when she started preparing meals for her family. That love of food blossomed into a quest to learn more and more about health and wellness as related to nutrition. She went on to earn a BS Degree in Food and Nutrition, then an MS Degree in Nutrition. She has taught nutrition and related courses at the college level to pre-nursing and exercise science students. Her hunger to learn didn’t stop upon graduation from college. She continues to research on a regular basis about nutrition as it relates to health. Her hope is to help as many people as possible to enjoy foods that promote health and wellness.