Agriculture Reference
In-Depth Information
Onions,
Leeks and Garlic
Onions are so familiar that it seems impossible that there could be anything at all com-
plicated about them. In fact, nothing is simple about this most basic of vegetables. Study
them very long, and you may feel you've followed Alice down some fragrant rabbit hole.
What seems to be one fairly consistent family turns out to be a wide and varied collection
of many overlapping clans that parade under a bewildering assortment of names.
Onions can be red, white, yellow or green. They can be as big around as a softball or
as tiny as a hazelnut. Some are even buttonshaped. They can be called Spanish, Bermuda
or Italian; spring, picklers, creamers, pearls or boilers. They can be sweet (those compose
a virtual atlas - they can be from Maui, Walla Walla, Vidalia, Texas or the Imperial Valley,
among other places). And then there are all those alliaceous cousins - garlic, shallots and
leeks. Making sense of so many choices can be maddening.
Where to start? Probably the most important thing to know is whether they are sold fresh
or dried. The vast majority of onions in the marketplace fit the latter category. They are
grown to full maturity before harvesting; indeed, picking doesn't start until the bulbs have
developed their full capacity of sugar and their green tops have withered and flopped to the
side. A kind of chain dragged behind a tractor "undercuts" the onions, destroying the root
systems and finishing the job. Usually, the fields are then mowed, removing the tops, and
the bulbs are left to dry for more than a week before being harvested. Finally, the onions are
removed to sheds, where fans circulate warm air constantly over the top. This curing pro-
cess removes moisture, which can encourage fungi. Curing also sets the papery skin, which
acts as a barrier against moisture and injury, further reducing the chances of spoilage. Dur-
ing this process anywhere from 3 to 10 percent of an onion's total weight is lost.
But onions also have a built-in mechanism for extending their shelf life, one with pro-
found benefits for cooks. Most alliums are high in sulfurous compounds that naturally in-
hibit spoilage. Perhaps more important, however, these compounds give onions and their
kin their distinctive character. Depending on the balance of specific components, the flavor
can range from the sharp, grassy green of spring onions to the sweet mellowness of leeks to
the orotund bass note of garlic. The base elements that form the flavors of most alliums (S-
alkenyl derivatives of L-cysteine sulfoxide, if you really want to know) are constant. But
