Issues > January/February 2003 (#94) > The Essential Onion

The Essential Onion

Onions have been cultivated for well over 5,000 years and for good reason, they are not only nutritious but also an essential flavoring ingredient in many dishes.

Look in almost any kitchen and you will find an onion or two, and yet how many of us know the difference between a Spanish onion and a Walla Walla?

Onion Varieties

Yellow onions are considered the most all-purpose onion. They are quite strong when raw but become very sweet when cooked, so sweet in fact that it sometimes seems as if you have added sugar to the cooking pot. Spanish onions are a common yellow onion.

White onions are not as sweet as yellow onions and should be added to dishes where added sweetness is undesirable.

Red onions are not only beautiful but also more mild flavored and so can be eaten raw or lightly pickled in red wine vinegar and sugar and added to salads. They are also great for grilling. They maintain their color and shape, while becoming soft and succulent.

Pearl Onions are most often white onions that are picked while still quite small, however, red and yellow varieties are also available. They are most often cooked and served whole, or pickled and served as a cocktail garnish.

Special Varieties

Cipolline are Italian pearl onions with a saucer-like shape. Like other Pearl Onions, they are a beautiful addition to a dish when cooked and served whole.

Vidalia onions, which are only grown in Georgia, Walla Walla onions from Washington state and Maui onions, from Hawaii, have a lower sulfur content, and a higher sugar content than the other varieties. They are very sweet and mild and are delicious when eaten raw.

Shallots are not really onions at all. They are a species of their own but are closely related and share many of the taste and health properties of onions. Shallots work very well in salads, as well as cooked dishes. Their flavor is milder than any of the onion varieties.

Growing Seasons

Onions are divided into two distinct categories based on when they are harvested. Fresh onions are available in the farmer's markets from March through August. Storage onions are purchased September through April. You will find that onions from the market in the summer are slightly sweeter than storage onions. They also have a higher water content and so bruise more easily.

Why They Make Us Cry

Onions are part of the genus Allium, which includes garlic, leeks, chives, shallots and scallions. The onion's spicy bite comes from the sulfur containing compounds that members of the Allium family contain. These compounds are highly volatile - meaning they easily become airborne - just cutting into an onion liberates these sulfur compounds which then get into (and irritate) our eyes and noses. You may have noticed that cooked onions do not make you cry. These volatile compounds are quite fragile and they actually float out of your cooking pot and dissipate into the air. This is the reason that cooked onions taste so much more sweet than raw onions.

Nutritional Information

Phytochemicals are compounds in plants that aren't vitamins or minerals and they don't contain any calories - nutritionists have only recently begun to understand the vital role they perform in our diet.

The same sulfur compounds that irritate your eyes and lend the characteristic flavor to onions are the phytochemicals responsible for protecting you from cancer.

Other phytochemicals are being shown to slow oxidative damage to the cells of the body and to have anti-platelet activity - preventing atherosclerosis, heart attacks and strokes.

Purchasing Onions

When buying onions at the farmer's market, more often than not, you will be buying fresh onions - remember that they bruise more easily but will have a sweeter flavor.

During the winter months - the storage onions that you buy should have dry outer skins without any spots and the onion should feel heavy for its size (this lets you know that there hasn't been excessive water loss) and should not be soft.

Storing Onions

Onions, especially the sweeter varieties (Maui, Walla Walla and Vidalia) keep best in the refrigerator where the cool temperature and higher humidity will help them retain their water content.

Unless temperatures are soaring, storage onions will be just fine on the counter in your kitchen.

Recipes

Dana Jacobi is the author of four cookbooks and contributed the soy section to The New Joy of Cooking. Her weekly food column "Something Different" appears in national newspapers. The following recipes are from two of her books, Amazing Soy (William Morrow Publishers, 2001) and The Best of Clay Pot Cooking (Harper San Francisco, 1995).

Onion Marmalade

Makes 1-1/2 cups

Dana writes, "This highly flavored condiment adds the same taste as you get from dehydrated soup mix, but in a wholesome way, with drastically less sodium. The Spanish onions have a pleasant sweetness. If you use regular yellow onions, sprinkle 1/2 teaspoon sugar over the onions just before adding the broth. The finished condiment keeps for weeks. Use it add flavor to dips, gravies, and sauces, and as a topping on pizza and focaccia."

Ingredients

2 large Spanish onions

1 tablespoon olive oil

1 tablespoon unsalted butter or olive oil

1 cup defatted beef broth or 1 tablespoon vegetable broth powder dissolved in 1 cup warm water

Freshly ground black pepper

Method

1. Thinly slice the onions, then chop them.

2. Heat the oil and butter in a large Dutch oven over medium-high heat. Stir in the onions until they are coated. Cook, stirring often, until the onions are translucent and look moist, 10 to 12 minutes. Tightly cover and reduce the heat to medium-low. Cook until the onions are soft and very wet, but not colored, stirring them 2 or 3 times, about 30 minutes.

3. Add the broth and bring the liquid to a boil. Reduce the heat, cover, and cook the onions gently until they are very soft. Uncover the pot and increase the heat to medium-high. Cook until the onions have caramelized to a golden brown and are almost dry, stirring often and scraping any bits sticking to the pot, 10 to 15 minutes.

4. Transfer to a container and cool to room temperature. Cover tightly and refrigerate. This marmalade keeps for up to 4 weeks.

Natural Onion Dip

Makes 2 cups

Of this recipe, Dana writes "This version of the classic onion dip contains a fraction o the sodium in the regular version made with soup mix. Plus you get all the good phytochemicals found in alliums."

Ingredients

1 cup onion marmalade (see recipe above)

1/2 cup (4 ounces) silken tofu

1/2 cup soy sour cream

1 teaspoon fresh lemon juice

Freshly ground black pepper

Method

1. Combine the marmalade, tofu, sour cream, and lemon juice in a food processor and puree. Season to taste with pepper.

2. Transfer the dip to a bowl, cover with plastic wrap, and refrigerate for at least 2 hours, to allow the flavors to meld and the dip to set up. Serve chilled. (This dip will keep for up to 4 days, covered and refrigerated.)

STUFFED ONIONS AGRODOLCE

These stuffed onions are often part of Italian antipasto. They can also be a good meatless main course. Their sweet and sour flavor is particularly typical of southern Italian cooking.

Serves 4

Ingredients

4 onions, about 2 1/2 inches in diameter

3 large plum tomatoes

1 cup cooked brown rice

1/4 cup golden raisins

2 tablespoons dried currants

1/2 teaspoon dried oregano

2 tablespoons red wine vinegar

2 tablespoons extra virgin olive oil

2/3 cup chicken broth, heated

Method

1. Preheat the oven to 375 F.

2. Peel the onions and cut across the top at the point where the sides of the onion start to curve towards the top. Cook the onions in boiling water for 2 minutes. Using a slotted spoon, remove the onions from the pot. When cool enough to handle, scoop out each onion with a melon baller, making a cup of 2 layers.

3. Halve, seed and dice 2 of the tomatoes.

4. In a bowl, combine the rice, diced tomatoes, raisins, currants, oregano and vinegar. Pack this mixture firmly into the onions. Place the onions in small casserole or baking dish just large enough to hold them.

5. Cut the remaining tomato into 6 slices. Place a slice on top of the filling in each onion. Drizzle the oil over the onions. Pour in the hot broth. Cover and bake the onions until they are soft when pierced with a knife but not mushy, 40-50 minutes. (If using a baking dish, cover it with foil.)

6. Place the onions on plate. Pour the liquid from the baking dish into small pan. Boil until it is reduced to 6 tablespoons. Spoon a quarter of the reduced liquid over each onion and serve, warm or at room temperature.

 

Onion images are courtesy of The National Onion Association.