Not usually thought of as a particularly good
source of nutrients, mushrooms actually rank rather high in nutritive
value. They contain a substantial amount of B vitamins, selenium,
copper, and some other trace minerals, and are very low in calories.
Moreover, researchers have discovered they contain antibacterial
and other medicinal substances, including anti-tumor compounds
The mushroom's distinctiveness derives, in
part, from the fact that it is not truly a vegetable but a fungus,
a plant that has no roots or leaves, no flowers or seeds, and
that does not require light to grow (although some do need light
to fruit). Instead, it proliferates in the dark and reproduces
by releasing billions of spores. There are about 38,000 varieties
of mushrooms, from deliciously edible to highly toxic. Most varieties
grow wild; in fact, their earthy flavour has been appreciated
for thousands of years. The Egyptian pharaohs decreed mushrooms
to be a royal food.
While some mushrooms still refuse to be "domesticated,"
many can be cultivated in caves or cellars, or grown year round
in specially designed structures in which all aspects of the environment,
light, temperature, humidity, and ventilation can be controlled.
As a result, many varieties of mushrooms are affordable and widely
available, no longer exclusively reserved for royalty.
To minimise waste in recipes that call for
caps only, choose mushrooms with short stems. Alternatively, reserve
the stems for another recipe.
For garnishing, or for cooking whole in a stew
or braise, choose small mushrooms; for general cooking purposes,
select medium-sized ones. For stuffing, look for mushrooms with
caps large enough to hold a generous amount of filling.
When shopping for specialty mushrooms, there
is no single rule of thumb for judging freshness since they are
all quite different and will not have the clean, uniform appearance
of cultivated button mushrooms, particularly if gathered in the
wild. They should, however, be firm and meaty, as well as dry
to the touch but not withered. Even uncooked, they should have
an appealing earthy fragrance.
It is important to conserve just the right amount of moisture
when storing mushrooms. If left completely uncovered, they will
dry out; if enclosed in moisture-proof wrapping, they will become
soggy and begin to decay. A good compromise is to place mushrooms
purchased in bulk in a loosely closed paper bag or in a shallow
glass dish covered with a kitchen towel or a lightly moistened
paper towel. Leave prepackaged mushrooms in their unopened package.
Don't wash or trim mushrooms before storing them.
Keep mushrooms on the refrigerator shelf, not
in the refrigerator salad drawer , which tends to be humid, for
no more than a few days. Unopened, prepackaged mushrooms will
stay for up to a week. If mushrooms begin to darken (and their
caps open) with age, they can still be used for cooking and flavouring
Dried mushrooms will keep almost indefinitely
if wrapped in plastic or placed in a tightly closed jar and stored
in the refrigerator or freezer. They can also be stored in a cool,
dark place for up to six months.
Since mushrooms are very absorbent, try to minimise their contact
with water when cleaning them. Simply wipe them with a dry paper
towel or a damp sponge or cloth, or use a soft brush (you'll find
special mushroom brushes at cookware shops, or you can use a small
soft-bristled paintbrush). If the mushrooms have a lot of soil
adhering to their stems, just trim off the stem bottoms. If absolutely
necessary, place the mushrooms in a colander and rinse them quickly
under cold running water; do not soak them or they will absorb
too much water.
Most mushrooms stems are edible. All you need
to do is trim off the very ends where the stem might be too spongy
(try cutting through the stem with a small knife; if it feels
spongy, trim off that section). If the recipe does not call for
stems, break them off at the cap and save them (chopped, wrapped,
and frozen) for later use in a stock or soup. However, shiitake
stems are usually too fibrous to be edible and should be cut off
before preparing the caps. (Use the stems to flavour stock.).