Salt and pepper aside, onions are probably the most-used ingredient
in any general subject cookbook. From mildly flavored chives and shallots
to pungent yellow globes, they enhance almost every category of recipe.
All onions belong to the lily family, and most are bulbs.
Understanding the characteristics of each lets the cook choose the best
type to use in any recipe.
Onions are typically divided into three groups: fresh, dry and
specialty.
FRESH
Chives: They are generally used as a fresh herb, either whole, chopped
or minced. To store, rinse, wrap in a paper towel and refrigerate in a
plastic bag up to 4 days.
Green onions: These are young onions harvested with the green tops
still attached. Used raw and cooked, either whole, sliced or chopped.
Store in a plastic bag, refrigerated, up to a week.
Scallions: The terms "green onions" and "scallions" are often used
interchangeably but, technically, scallions are shoots from white onion
varieties pulled before the bulb has formed.
Leeks: Sweet and mild, those less than 1 1/2 inches in diameter are
the most tender. Refrigerate, unwashed, in a plastic bag for up to a
week. Cook before serving.
DRY
Boiling: These are white onions 1 to 1 1/2 inches in diameter. To
peel, cover with boiling water, let stand 2 to 3 minutes, then drain and
slip off outer skin. Cut a shallow "X" in the stem end to ensure even
cooking and prevent the layers from separating. Used mainly in soups and
stews or sauced as a vegetable.
Cipolline: These intensely flavored, crisp, button-shaped onions, also
called Borettana, are from Italy. Used raw and cooked, they are similar
to boiling onions.
Pearl: They may be white, brown or red. Peel as described for small
boiling onions and use in soups, stews, alone or in combination with
other vegetables.
Red: They are similar to Spanish but less pungent. They are best used
raw because they lose color when cooked.
Spanish: This type of yellow onion has higher moisture content and is
more perishable. Good raw, sauteed or caramelized.
Sweet: Almost all sweet onions come from the same variety, though
there are subtle differences in flavor depending on their place of
origin. They aren't actually sweeter than regular storage onions, they
just taste that way because they are lower in acidity. They are best used
raw or cooked only briefly, and they make great onion rings.
The Maui variety from Hawaii is the first to appear, in late winter or
early spring, followed by the Vidalia from Georgia in late spring. Both
are yellow onion hybrids but, because of the soil and climate where they
are grown, the flavor is milder and sweeter.
Nu-Mex and Texas 1015 onions also come from this variety.
Walla Walla onions, grown in Washington state, are a distinct variety
developed primarily from Italian seeds. They are harvested in summer.
Sweet onions are traditionally stored in stockings or pantyhose
separated with knots. Hang in a cool place and cut them from the bottom
as needed. They can also be wrapped separately in foil and refrigerated.
Use as soon as possible because high moisture content makes them more
perishable than onions that are field-dried, and heat develops as they
age.
White: These are mild when first tasted, but the heat increases. They
have more moisture, so are more perishable than yellow onions. Best for
sauteing and stewing.
Yellow: This is the most common cooking variety. Size ranges from very
small to moderately large. The all-purpose onion may be eaten raw or
cooked; it loses heat when cooked.
Red, Spanish, white and yellow varieties are grown during the summer.
After being pulled from the ground, these onions are dried a few days in
the fields before being stored.
Kept in a cool, dark, dry place with good air circulation, dry onions
will keep for months.
SPECIALTY
Shallots: These have small bulbs made up of cloves, similar to garlic,
and a mild, delicate flavor. They are used raw and cooked and should be
stored as outlined for dry varieties.
TIPS
**Chopping onions in a food processor bruises the pieces and results in
a stronger, more bitter flavor than when they are cut by hand with a
knife. Knives with stainless steel blades are preferred because carbon
steel sometimes discolors the onions.
**No remedy for tearing are foolproof, but it helps to peel onions
under running water to rinse away vapors and to chill them before
cutting.
**Cooking time and temperature affect the flavor of dry onions. A short
period of high heat brings out strong onion characteristics more quickly.
Long cooking over low heat caramelizes the natural sugars in onions and
diminishes the strong taste. Sauteing over medium-high heat brings out
the most flavor.