Long prized for its unique
properties, agarwood is becoming more and more difficult to obtain.
Over-harvesting, encroaching civilization, and environmental changes have
greatly reduced the population of agarwood, but the demand for it is still very
much alive. There are several species of evergreen which can produce agarwood,
and most are listed as vulnerable and near threatened. Today, the agarwood
producing trees are confined to the regions of Kampuchea (formerly Cambodia),
Laos, Burma, and Vietnam.
The agarwood, or aquilaria
malaccensis, which is the primary source, is a variety of evergreen found in
Southeast Asia. The tree’s heartwood becomes infected with a peculiar type of
mold, which creates a thick secretion of sap and darkens the wood. This
secretion makes the wood extremely hard and durable, and it is this incarnation
that is much sought after. The resinous sap is extremely aromatic, and has no
equal. Prior to the tree becoming infected, it is a light colored wood of
medium density. In this form, the wood is less desirable, and thus, less
valuable. Only 6 to 8% of the trees that produce the coveted wood are infected
with the mold, but artificial introduction of the spores to “clean” trees is
sometimes implemented.
Agarwood is used primarily
in the production of incense, perfume, medicines, and other essential oil
products. It is believed to be an aphrodisiac, and has been used for centuries
in religious ceremonies. One of the earliest known usages was documented in the
Sanskrit Vedas that originated in India. Chinese chronicles from the Wu dynasty
in the 3rd century include references to the agarwood’s cultivation
in what is now known as central Vietnam.
In more primitive areas, it
can take up to a week on foot to find the first infected tree. The trek is
fraught with everything you would expect in a jungle, and malaria is a real
concern. Most of the time, harvesting takes place on an outcropping or cliff,
and the work itself is dangerous and difficult. The wood is toted out on the
backs of the reapers, each man carrying up to 75 kilos of wood.
The harvested wood is used
for distilling to get the valuable oil. The most common form of agarwood (oud)
oil extraction is to use a steam distillation method. This effectively
dissolves the resin and is collected in batches. In order to extract 20 ml of
oil, around 70 kg of wood must be harvested. The wood is distilled for up to a
week to extract the coveted oils.
Dead or dying live wood is
not distillable. However, it is sold at a higher premium and is usually powdered
to make incense or manufactured into cultivated agarwood chips to make various
other products. Some really infected wood is so permeated with resin, that if
you use a sharp knife and slice off a thin piece, it will curl like hard wax.
It is not uncommon for powdered agarwood chips to be used in medicines that are
taken internally, for example.
Whatever the use or application, you can be
sure that cultivated agarwood will continue to increase in value as the supplies
get smaller.
