Agriculture Reference
In-Depth Information
the trace elements (1-propenyl-1, 2-propenyl-1, 1-propyl and methyl-L-cysteine sulfox-
ide) change, and those provide the distinctive differences.
What's really amazing is that in many cases those distinctive flavors - and even the
chemical compounds that create them - are produced only when the flesh of an allium is
bruised or cut. That damages the plant's cell walls, allowing the contents to combine. En-
zymes react with existing compounds to create new ones, starting a split-second chain of
chemical reactions that results in what we instantly recognize as onions' taste and smell.
The most common storage onions are the round brown ones (called yellow onions) that
we often buy in big bags. They last the longest and tend to have the highest concentration
of sulfur. White and red storage onions (both are sometimes called "Bermuda," which was
once an important center of onion agriculture) tend to be slightly more delicate in flavor
and don't store as well because they contain less sulfur. For this reason, they are frequently
used raw. These are both round onions, but particularly in Italian neighborhoods, you can
also find red onions shaped like torpedoes. These taste pretty much the same as round red
and white onions. Small storage onions - called pearls, picklers, creamers, boilers and ba
bies, depending on their size and the whims of marketers - come in all three colors as well.
They are grown tightly packed together to limit their size. They all taste pretty much the
same as well; their big draw is visual. The primary exception is the small, flattened Italian
cipolla (also known by the diminutive "cipolline"), which has a fuller, rounder, sweeter
flavor.
Other onions are picked fresh. The most common of these are the familiar pencil-
shaped green onions. They are sold under a confusing variety of names - spring onions on
the West Coast (though they are available year-round), scallions (on the East Coast) and,
peculiarly, shallots (in Louisiana). Green onions are usually harvested well before they
reach maturity and have begun to form a swelling bulb. Most important to a cook, they are
picked before they have developed either much sulfur or much sugar. Their taste is mildly
sharp and green (from the high chlorophyll content). Green onions also can be picked at
the bulb stage, when the flavor is a little more developed. These are especially good for
cooking whole, as the slightly larger size allows a pleasing range of textures.
To compound the confusion, there is also a branch of the family called "bunching
onions." They look much the same as green onions, although their tops are a little more
structured - when you slice them, they come away perfectly round rather than elliptical.
The flavor is noticeably fuller and less pointed, as well as a little sweeter, than that of
green onions. The king of the green onion is the Japanese variety called negi or nebuka,
which is grown buried in the earth, like a slim, sharp leek. And then there are chives,
