An Onion Primer

Onions are one of those foods that every cook needs in their pantry. They are the basis of so many savory dishes. All the different types of onions can mean that such a simple vegetable can become confusing. In this Cooking Tip, I would like to try to clarify a bit about onions although it won’t be an exhaustive list of onion types. (For a much more in-depth discussion of onion types, refer to the National Onion Association website – yes there really is such an organization.)

Even though you can find onions in your supermarket year-round, they actually are seasonal. Spring/Summer onions are available March through August. Because they have just recently been harvested, they tend to be milder in flavor and, therefore, can be used in a raw form as well as cooked. Fall/Winter onions (aka storage onions) are left to grow longer resulting in larger onions with thicker skins and less moisture content. This means they last longer in storage but are also more pungent in flavor. To reduce this pungency, they are best in cooked applications.

Scallions are also known as green onions. (Some food experts would disagree with this generalization.) They are long and thin with a white bottom and dark green tops. They have a mild taste and can be used raw or cooked. They are wonderful thrown on a mixed green salad. I also love them as one of the toppings on a bowl of chili.

Spring onions are very young storage onions. They are harvested very early, which results in thin skins and a mild flavor. They look similar to scallions but have a larger bulb at the bottom. Although they are slightly spicier than scallions, they can still be used in a raw manner. They will sweeten up when cooked and are often grilled.

Shallots are small in size and range in color from white to rose. They are fairly mild and are often used in making sauces, vinaigrettes as well as Asian dishes.

Yellow onions are the most all-purpose. According to the National Onion Association, these onions account for about 87% of the onion crop in the US. If a recipe does not specify what type of onion, reach for one of these. They definitely have an onion flavor but are not overpowering. Although not great in a raw form, they turn wonderfully sweet when cooked.

Spanish onions look similar to yellow onions and may be displayed next to each other in the store. Because they are grown in a low sulfur soil, they are less pungent and tend towards sweetness. Beware, however, some stores do not differentiate between Spanish and yellow onions.

White onions are a staple in Mexican cooking. Some think they are milder and sweeter than yellow onions but they do tend to be tangier.

Red onions are often eaten raw but they can be fairly pungent. They are great for pickling and for topping tacos, chili or burgers. They also make a great addition to a roasted vegetable dish.

Leeks are also in the onion family. They have the shape of scallions but are much larger in size. Whereas the green portion of scallions can be eaten, the green part of leeks is very woody and is only good for flavoring stock. The white portion, however, is very mild and sweet. Despite that, they are usually not eaten raw as they tend to be fibrous in texture. They are a great base for certain soups and I make a great chicken pie that uses leeks and garlic as flavoring elements.

Sweet onions such as Vidalia and Walla Walla are very low in pyruvic acid. This is the component that makes your eyes tear when cutting them. Because of this, they are extremely mild in flavor. Another onion I have recently discovered is Sunions. Grown only in Nevada and Washington, they are a result of cross-breeding to produce a tearless, sweet and mild onion. The company claims to certify these characteristics before shipping to grocery stores. I recently received some samples and have just started trying them. Although I need to test them more, they do indeed seem to live up to their claims. I just saw that my local King Soopers (a Kroger store) has started carrying these.

Pearl onions are very small onions that are also mild. Although most often found in a white variety, pearl onions can also be yellow or red. They are generally not found loose and often hard to find fresh. Bags of frozen, pre-peeled pearl onions are usually fairly easy to find. Uses include pickling dishes & casseroles and even as a separate side dish.

Chives are relatives of onions but we also consider them an herb. They have a very mild onion flavor and, therefore, are often eaten raw in salads. They are also great sprinkled on an omelet and other dishes where you want a mild onion flavor. They make a nice garnish because of their vibrant green color. Cooking them is not recommended due to flavor loss.

With all these options, what should you keep around at all times? The answer may vary according to how you cook but I always have all-purpose yellow onions on hand. I also have a red onion available, a bunch or two of green onions as well as a few shallots. With these, I can make almost any onion-containing dish.