A Beginner's Guide to Onions
Can you imagine a world without onions? These alliums—members of a family that also includes garlic and chives—are indispensable, adding a baseline of sweet and earthy flavor to many cooked dishes and contributing a spicy accent when served raw. But even if you use them almost every time you cook, onions can still be pretty bewildering. With about a dozen varieties readily available in most markets, as well as several less common types, it can be hard to know which kind of onion to choose for your marinara sauce and which to select for your pico de gallo. Never fear: let our ingredient guide come to the rescue.
Because they last so long in storage once they've been harvested—undoubtedly a major reason why onions are such an integral part of so many cuisines the world over—they're available (and tasty) year-round. But onions are still seasonal: spring/summer onions, available March through August, have been recently harvested, and therefore tend to be sweeter and milder, excellent for use in raw applications. Fall/winter onions come from the same plant as spring/summer varieties, but are left in the ground a few weeks longer: beneath the surface, the onions grow larger, losing moisture and developing a thicker skin along the way. Ideal for storing, they also tend to taste more pungent, and are usually most delicious when cooked. Read on to learn more, or jump to the onions you're curious about.
Onions You Should Know
One of the most versatile onions around, scallions are long and thin, typically no fatter than a finger. Sweet and mild with hardly any bite to them, they can be used raw or cooked and fit right in to any number of dishes.
What They Look Like: Bright white at the bottom with hollow, dark green tops, scallions are usually sold in bunches.
How They Taste: Scallions provide a gentle onion flavor, but are just as much about their texture: they're crunchy and juicy at the same time. Their dark green tops tend to have a bit more bite to them, and are best used as an accent, as you would fresh chives or parsley.
How to Shop and Store: Look for scallions from late spring to late summer, when they're harvested fresh and are at their peak. The onions' white sections should be firm and bright, without any moisture or sliminess, and the tops should be sturdy—avoid any bunches that have wilted tops. Never store fresh scallions in a plastic bags: their high moisture content will quickly lead to rot. Reusable mesh produce bags tucked into a crisper drawer are a great option: they allow air circulation, but keep the scallions from drying out. If your scallions still have roots, trim them slightly, stick 'em in a glass jar you've filled with a couple inches of water, and stash 'em in the fridge for up to a week.
How to Use Them: Along with garlic and ginger, scallions are indispensable to stir-fries. Flaky scallion pancakes are a quick, tasty indulgence, and fresh chopped scallions bring brightness to stuffed, grilled beef teriyaki.
Though spring onions resemble scallions in appearance and flavor, they're actually just very young storage onions—yellow, red and white—that are pulled out of the ground at an earlier date, when they're still thin-skinned and mild in flavor.
What They Look Like: Just like scallions—white bottoms and dark green tops—but with a bulb at the bottom, instead of completely straight.
How They Taste: Still mild in flavor, spring onions have just a touch more spiciness to them when eaten raw. When cooked, they're tender and sweet.
How to Shop and Store: For shopping tips, see scallions, above. For storing, reusable mesh produce bags are, again, the best option; if you don't have any, roll spring onions in a just-slightly-damp kitchen towel, secure with a rubber band, and store in the crisper drawer for up to one and a half weeks.
How to Use Them: Grilled spring onions are so lovely—charred yet sweet, tender but crisp—that they're one of the most prized dishes in Catalunya, the mountainous region on the Spain-France border. The exact type of spring onion grown in Spain isn't available here, but the idea remains the same): lightly oil the onions (with tops), grill over charcoal until soft, and serve with romesco sauce. Spring onions also take wonderfully to pickling; try them spooned over hot dogs as an alternative to sauerkraut.
Vidalia is the legally-registered name of the squat, ovoid, sweet yellow onion that's grown in and around the town of Vidalia, Georgia. Extremely low in pyruvic acid—which, when exposed to air, makes your eyes tear—Vidalias are among the mildest in the onion kingdom.
What They Look Like: Narrow at the stem and root, and wide around the middle, like a spinning top, with a thin, papery, light yellow skin.
How They Taste: Super-sweet and crisp, ideal for eating raw.
How to Shop and Store: Look for Vidalias in the markets between late April and early September. Firm, medium-sized onions without any bruises will taste the best. To store, wrap each onion in a paper towel and store in the fridge; they'll keep for weeks.
How to Use Them: In late summer, when both Vidalias and tomatoes are at their peak, it's tough to beat a basic sliced tomato salad with slivered onions and a simple oil-and-vinegar dressing. When the weather turns cooler, this mac 'n' cheese recipe will do nicely. And Vidalias, when caramelized, add deep sweetness to rich, fluffy mashed potatoes.
Whether you can't get enough of them or think they're a wee bit overrated, there's no denying what ramps signify: spring, and the return of fresh, delicate produce after a long, cold, potato-filled winter. Count us in the ramps-loving camp: these wild spring leeks have a pungent garlic-onion flavor in their base, which softens and becomes mild in the leaves.
What They Look Like: Kind of like scallions, but with large, broad, flat bright-green leaves up top. The slender white bottom sections often have a dash of bright purple or magenta joining them to the leaves. While they're pretty expensive in many major cities, ramps grow like weeds in places like Appalachia and Quebec.
How They Taste: Like a cross between garlic and onions, with a pronounced funk that's almost cheeselike. The edible tops are notably milder and sweeter than the bulbs at the bottom.
How to Shop and Store: Often heralded as one of the first signs of warmer weather, ramps have a short season, showing up in farmers markets in late winter and only staying there until early spring. Their bottom sections should be firm, never slimy, and the tops should be bright without any wilting. Ramps don't store super well, but will keep in the refrigerator for a few days in reusable mesh produce bags tucked into a crisper drawer.
How to Use Them: Throw 'em on the grill. Or pickle them. Put ramps in your dumpling filling and your Mapo Dofu. Put ramps in your chorizo quesadilla. Add ramps to biscuits and frittatas. Make ramps into soup with fresh asparagus. Cook up an extra-rampy ramp risotto. And don't forget about ramp butter on toast.
Yellow onions are undoubtedly Americans' favorite: nearly 90 percent of onions grown in the US are yellow. Their deep but not-too-strong flavor 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.
What They Look Like: Ranging in size from golf ball to softball, with light yellow flesh and golden, papery skin.
How They Taste: Assertive when raw, deeply sweet when cooked.
How to Shop and Store: Yellow onions are available year-round: in summer and early fall, 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: an open basket or a bamboo steamer in a cooler part of the kitchen works. 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.
How to Use Them: How not to use them? Yellow onions are ideal for long-cooking in soups, stews and braises, and of course are sticky and delicious when caramelized. Feeling impatient? Check out Kenji's genius method for caramelizing onions much, much faster, and then make yourself some French onion dip.
Many cooks don't know the difference between white and yellow onions. The white versions are somewhat sweeter and cleaner in flavor, but don't store quite as well as yellow onions do.
What They Look Like: Ranging in size from baseball to softball, with white flesh and bright white, papery skin.
How They Taste: Milder in flavor than yellow onions, white onions can be eaten raw.
How to Shop and Store: 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.
How to Use Them: Because of their crisp texture and mild flavor, white onions are great raw slivered in salads, thinly sliced on your favorite sandwich, or scattered over a pizza. Popular in Latin American cuisines, white onions are a great addition to huevos rancheros, refried beans, and Cuban picadillo. Feel free to sub them for yellow onions in cooked dishes, too.
Though they can be pungent and spicy, red onions are great for eating raw, bringing crunchiness and brightness to a variety of dishes. You might see them all the time, next to the yellow onions on the supermarket shelf, but red onions only make up about eight percent of the onion market in the US.
What They Look Like: Ranging in size from golf ball to softball, with bright maroon flesh and dark red, papery skin.
How They Taste: Assertive and spicy when raw; still strong, but sweeter, when cooked.
How to Shop and Store: Red onions are available year-round: in summer and early fall, 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. Bulb onions should be stored in a dark, cool, dry location; see advice for yellow onions.
How to Use Them: Red onions take extraordinarily well to pickling, whether they're destined for the top of tacos or folded into a bright ceviche. Put red onions on your pizza and try them in a chopped salad with cherry tomatoes and bell peppers. We also love red onion jam as a burger topping or spread on crackers.
Where would be be without shallots? They're often seen in French cuisine, where they're featured in classic sauces such as mignonette. They're also indispensable to Asian dishes—often crisp-fried or ground into curry pastes.
What They Look Like: Shallots are available in a wide range of shapes and sizes. Western shallots, the kind you're most likely to encounter in a U.S. supermarket, are small, slender and lighter in color than red onions, with pinkish-orangey papery skin and light purple flesh. In an Asian market, you might find Asian shallots, which are very small and deep dark purple.
How They Taste: Milder in flavor than red onions, but more assertive than yellow, with a hint of garlic flavor.
How to Shop and Store: Available year-round, shallots' flavor intensifies throughout their winter storage. Look for firm, compact shallots with shiny, unblemished skin. Kept dry and stored in a cool, dark area of the kitchen, like a cabinet, shallots will keep for several weeks to a month.
How to Use Them: Thinly sliced and fried for topping Thai curried noodles, congee, or deviled eggs; minced into basic vinaigrettes for added crunch and flavor. You'll need shallots to make the Ultimate Thanksgiving Green Bean Casserole, and we love them roasted under a whole chicken.
Tiny and sweet, pearl onions come in yellow, red, and white varieties, with the latter being the most common.
What They Look Like: These cuties look just like regular onions but are about the size of a jawbreaker.
How They Taste: Much milder and sweeter than large bulb onions.
How to Shop and Store: Pearl onions are sold year-round, usually in small mesh bags—they're not easy to find loose, and can be difficult to find altogether, so frozen, pre-peeled bags of pearl onions are an appealing option. If buying fresh, store as you would large bulb onions.
How to Use Them: The biggest annoyance about using fresh pearl onions is peeling them: to do so quickly and easily, blanch them in hot water, then slip off the skins with your fingers. After that, simply glaze them, cream them in a bubbly gratin, orpickle them for use in a Gibson cocktail. They're lovely roasted with balsamic, too.
These little disc-shaped yellow onions, which might remind some people of visitors from outer space, were once reserved for the world of gourmet stores and fancy restaurants, but nowadays are pretty widely available in large supermarkets.
What They Look Like: Slightly larger than pearl onions, with a squat disc shape and pale yellow skin.
How They Taste: Extra sweet.
How to Shop and Store: Cippolini are sold year-round, sometimes in mesh bags. Store in a cool, dark place.
How to Use Them: I'll be honest: cippolini are kind of annoying to peel. You'll need to lop off their root and stem ends with a sharp knife, then use a paring knife to strip away remaining peel. Because of their high sugar content, cippolini take wonderfully to caramelizing. Roasted all on their own, they make a great holiday side dish. Try them, also, in sautéed green beans with mushrooms. Tossed with balsamic vinegar, they're excellent roasted under a mustard-rubbed ham.
Leeks look a lot like scallions, but in fact they're a totally different plant. Larger in size than their spring counterparts, leeks' white portions are tender and sweet, but their dark green tops are woody and best reserved for flavoring stocks.
What They Look Like: You might mistake them for big, overgrown scallions.
How They Taste: Extremely mild, with a pronounced sweetness. Because they're so fibrous, leeks generally aren't eaten raw.
How to Shop and Store: Leeks have been bred to survive the winter months, and are in season from late fall to early spring. Leeks can be pretty gritty and sandy: be sure to wash carefully before cooking. If you need to store them, trim off a portion of the dark green tops, place in a reusable mesh produce bag or roll them in a just-slightly-damp kitchen towel, secure with a rubber band, and store in the crisper drawer for up to one and a half weeks.
How to Use Them: Though too tough to eat when raw, leeks melt into wonderful softness when cooked. One of the most appealing ways to cook them is braised in stock and olive oil, then dressed with a lemony vinaigrette. Leek soup with lemon and dill is an economical winter warmer, and a beef and leek stir-fry is lightning-fast and delicious. Creamed leeks are lovely under seared fish, and sauteed leeks make a surprisingly excellent sandwich filling.