Onions come in all shapes and sizes and a variety of colours, and their textures and flavours can be quite different. Different types of onions can’t necessarily be substituted for one another. So how do you know which onions are best for which dishes? From French onion soup to succotash, the onion varietal you use does matter! To help get your onions in order, take a look at the most common ones: white onions, green onions (scallions), pearl onions, red onions, shallots and yellow onions, among others.
Fleshy layers attached at the root end are covered with layers of thin paper skin that develop as the onion matures. The bite of raw onions is due to sulfur compounds. When an onion is cut, the crushing of the cells and contact with air releases allicin—which in turn causes one’s eyes to water.
Onions range in size from tiny—less than 2,5 cm in diameter—to jumbo—more than 11,5 cm in diameter. Onions are also seasonal, divided into two categories, although imported onions make most types available year-long. Yellow, white and red onions are available in both categories.
Spring/Summer onions (March through August in the northen hemisphere): With thin, lighter-coloured skin, these onions are typically higher in water content, which reduces their shelf life. These more delicate onions, range in flavour from sweet to mild. They are popularly used in salads, sandwiches, and lightly-cooked dishes.
Fall/Winter onions or Storage onions (August through May in the northen hemisphere): These onions have multiple layers of thick, darker coloured skin, are typically lower in water content, and thus have a longer shelf-life. These are heartier onions, ranging in flavour from mild to pungent. They are popularly used for savoury dishes that require longer cooking times and/or more flavour.
Bermuda Onions: These onions have white, yellow or red skin, depending on the variety. Most Bermuda onions cultivars have flat tops, white flesh and a mild, sweet flavour. Popular Bermuda varieties include white Bermuda, yellow Bermuda crystal wax, red burgundy and excel.
Cipollini Onions: These small onions are distinct, flattened flying saucer-shaped onions from Italy. They are unusually rich and sweet but more perishable than round pearls. You may also find red cipollinis at farmers markets and specialty stores.
Maui Onions: One of the world’s sweetest varieties, Maui onions lack the sulfur which causes the strong odour and sharp taste associated with onions. In addition to being very sweet, the Maui onion has a high water content, making it quite juicy. There are a number of ways to use these flavourful onions; baked, broiled or stuffed, the premium growing conditions on the Hawaiian island of Maui ensures that these onions have a sweet, delicate, unmistakeable flavour. Some people enjoy eating them raw out of hand, and they are also good when sliced thinly on salads, sandwiches, and other dishes. The onions can also be cooked, bringing out even more of the naturally sweet flavour; they are great grilled, barbecued on skewers with chicken, beef, or lamb, or when used in soups, stews, and casseroles, they can also be marinated with other vegetables for kebabs, included in stuffings, or used to make distinctive sauces. Store onions whole, unwrapped, in a cool, dry place for up to 2 months. Wrap cut pieces in plastic wrap and refrigerate for up to 4 days.
Pearl Onions: These tiny onions are smaller than boiler onions and contain a sweet, mild flavour. They are available in white, red and gold varieties. Because of its uniquely diminutive appearance and a taste sweeter than that of a common onion, it is used in dishes ranging from American casserole dishes such as succotash, sweetly flavoured onion relishes in Indian cuisine, creamed or pickled. Look for pearl onions that are firm, heavy for their size and have dry, papery skins. When selecting pearl onions avoid any signs of moisture, green shoots or dark spots. Keep in mind that humidity breeds spoilage in dry onions. Store whole pearl onions in a cool, dry place with good air circulation for up to two months. Once cut, tightly wrap any unused onion in plastic, refrigerate and use within four days.
Red Onions: Mild red onions have a beautiful dark-red to purple outer paper skin. Inside, their juicy, crisp and sweet white flesh is edged with colour. These onions are sometimes called purple onions, because of their reddish-purple colour. Red onions are available in regular and jumbo sizes. Add them to salads and appetisers for a little flare with the added reddish purple colour. Red onions are great raw, chopped, diced or sliced into salads, salsas, dressings and marinades, mixed with vegetables, roasted whole, or grilled, especially when sliced into thick rings. Simply brush with oil, sprinkle with salt and pepper, and let them cook about 3-5 minutes on each side. They are complimentary to any vegetable dish and are wonderful with heirloom tomatoes and basil. Red onions should have dry papery skins with no brown discoloration. Choose firm bulbs with even-coloured skins and no signs of sprouting; avoid any that look damp or smell musty. Store red onions at room temperature and use as desired. Onions will last as long as a few months.
Scallions: Also known as spring onions or green onions. This long, thin varietal is commonly found in Asian cuisine. Scallions are pulled while the tops are still green and before a large bulb has formed. They are mild and need little to no cooking time. Scallions may be cooked or used raw as a part of salads, salsas, or Asian recipes. Diced scallions are used in soup, noodle and seafood dishes, as well as sandwiches, curries or as part of a stir fry. In many Eastern sauces, the bottom half-centimetre of scallions roots is commonly removed before use.
Shallots: These are used in fresh cooking in addition to being pickled. Finely sliced, deep-fried shallots are used as a condiment in Asian cuisine. Shallots taste somewhat like a common onion, but have a milder flavour. Shallots appear to contain more flavonoids and phenols than other members of the onion genus. Fresh shallots can be stored in cool, dry area for six months or longer.
Tropea Onions: The football-shaped, red torpedo onion from Tropea, Italy is a particular variety of red onion which grows in a small area of Calabria in southern Italy near the city of Tropea. This onion has a stronger and sweeter aroma and the inner part is juicier and whiter than other red onions. In Calabria these red onions are eaten raw in salads; cooked in sauces; roasted or grilled; placed on top of pizza or in frittate; made into jam, and even added to ice cream!
Vidalia Onions: The onions are named Vidalia because of where they are grown, Vidalia, Georgia. The different varieties are unusually sweet, due to the low amount of sulfur in the soil in which the onions are grown. The unique flavour of the sweet Vidalia onion is attributed to their low pungency and high sweetness levels. Vidalia onions are considered by many chefs to be the “premium” among sweet onions as they are very versatile and can be used to add flavour and sweetness to a wide variety of chef-inspired recipes from salads to side items, to dressings, dips and yes, even desserts. They are great for onion rings, or baked with butter until they're soft and served as a side dish.
Walla Walla Onions: These sweet onions were brought to Walla Walla, Washington, from Corsica at the beginning of the 20th century. These “French” onions were developed over several generations to be exceptionally sweet, jumbo-sized, and round, with an elongated neck and dry, paper-thin skin. They have a higher water and sugar content than storage onions, making them more susceptible to bruising, and must therefore be handled with care. Since Walla Walla onions are available for only a portion of the year, sweet onion lovers buy them in quantity and store them for extended enjoyment. The key to preserving these sweet onions (and to prevent bruising) is to keep them cool, dry, and separated. Walla Walla onions have a distinctly different flavour – milder and sweeter – than any other onion, so they are excellent in salads and sandwiches where hot onions would be overpowering. You might want to try some of these favourite methods of storage. (Storage tips from Walla Walla River Packing Co)
Place Walla Walla onions in the legs of clean, sheer pantyhose. Tie a knot between each onion and cut above the knot when you want to use one. Hang in a cool, dry, well-ventilated area.
Place Walla Walla onions in the refrigerator, wrapped separately in paper towels or newspaper. This method is expensive and takes up precious refrigerator space, but can preserve these sweet onions for a longer period of time.
Place Walla Wallas on elevated racks or screens, not touching and in a cool place.
Walla Walla onions can be chopped and dried in the oven. Use the lowest setting and remove from the oven when thoroughly dry but not brown. Store at room temperatures in airtight containers.
Walla Walla onions can also be frozen. Chop and place in a single layer on a cookie sheet in the freezer. When frozen, remove and place in freezer containers or bags and seal. This method allows you to remove the amount you want when you want it.
NOTE:Freezing changes the onions' texture, so frozen onions should be used for cooking only. Whole frozen Walla Wallas can be baked.
If stored properly in a cool and well ventilated location, Walla Walla onions will stay fresh for 3–6 weeks or they can be frozen for use well into the year.
White Onions: These onions are an all-purpose onion, they are commonly used in white sauces, pasta salad, potato salad, and in Mexican and Southwestern cuisine. As they’re an all-purpose onion they work in any recipe that calls for onions. They are suitable for sweating onions or sautéing them for a sauce or stew. White onions are somewhat sweeter and cleaner in flavour, but don't store quite as well as yellow onions do. They range in size from baseball to softball, with white flesh and bright white, papery skin. Milder in flavour than yellow onions, white onions can be eaten raw. White onions are available year-round and taste the same throughout the seasons. Look for firm, unbruised onions that are heavy for their size. Bulb onions should be stored in a dark, cool, dry location.
Yellow Onions: Also referred to as brown onions are the best type of onion for caramelising, cooking brings out this variety’s nutty, mellow, often sweet, quality. Their deep but not-too-strong flavour makes them endlessly versatile in cooking. Larger, slightly sweeter yellow onions labeled Spanish onions are often found right next to plain old yellow onions; they're a milder choice that works well for raw applications. Yellow onions range in size from golf ball to softball, with light yellow flesh and golden, papery skin. They are assertive when raw, deeply sweet when cooked. Yellow onions are available year-round: in summer and early autumn, when they haven't been in storage long, they taste sweeter, with their sharpness intensifying through the winter months. Look for firm, unbruised onions that are heavy for their size. If you plan on using your bulb onions within a few weeks, they can be stored at cool room temperatures in a dark place. If you plan on storing them longer, wrap them individually in paper towels or place them in a breathable vegetable storage bag and keep them in the refrigerator. Cut or peeled onions can be stored, wrapped in plastic, in the refrigerator for only a few days before they go mushy. Yellow onions are ideal for long-cooking in soups, stews and braises.
Pickling Onions: Sometimes called “boilers”, are small tender white or yellow onions with a mild flavour. They range in size from 1,25–2,5 cm in diameter. Their small size and mild flavour sets them apart from the typical yellow onion. Pickling onions can often be found during summer and autumn in the produce department of grocery stores.
Pickled Onions: These consist of onions pickled in a solution of vinegar and salt, often with other preservatives and flavourings. The onions are pickled peeled, but whole. English-style pickled onions are very crisp and crunchy, and have a very sharp taste that stands up well to sharp, full-flavoured English cheeses. They are brownish, because they are pickled in malt or apple cider vinegar, with brown sugar, salt and black pepper added to the mix. North American store bought pickled onions tend to be quite bland compared to the English ones made commercially. Plain, white vinegar is used, giving a harsh taste. They tend to be soft; some can be almost spongy. In the United Kingdom they are often eaten alongside fish and chips or as part of a ploughman's lunch. Full sized onions, e.g. Spanish Onions, can be pickled if sliced first. In the Southern United States, pickled Vidalia onions can be served as a side dish.
To lessen crying, chill an onion before chopping and use a very sharp knife.
Peel away the papery outer skin and any blemished layers.
If the onion will be chopped, trim off the top and peel the outer layers while leaving the root end whole. (The root end contains the most sulfuric compounds.)
Note: To cut down on sharpness when serving raw onions, place in a bowl of ice water for 30 minutes and then drain.
Walla Walla onions add a distinct sweetness to any dish, but they are delicious all by themselves, baked or raw.
Use thick slices on hamburgers or with grilled steak.
To enjoy a raw Walla Walla, we recommend placing a whole, raw, unpeeled onion in the refrigerator. Chill for approximately one hour before serving, or peel and cut into slices and place Walla Wallas into a bowl of ice water for approx 30 minutes – then drain on paper towels. Either of these methods will help bring out a sweeter flavour when eating raw Walla Wallas.
To bake a Walla Walla, peel and then cut off the top and bottom of the onion to make it sit flat. Place a pat of butter on the top, then microwave for 7 minutes on high. To prepare in a conventional oven, wrap securely in foil and bake at 180°C (350°F) for 45 minutes or until tender.
Marinate pearl or cipollini onions and thread on kebabs for grilling.
Roast whole small onions at high heat till they are caramelised (peel before or after roasting).
Top sandwiches, salads, or burgers with slices of red, white, or yellow sweet onion.
Make pink onion pickles by soaking sliced red onions in ice water and vinegar until the onions turn pink, then drain and serve.
Onions complement any savoury food.