What Is Oud?

Oud — also called agarwood, aloeswood, gaharu or jinko depending on where you are standing — is one of the most expensive raw materials in perfumery, and one of the most widely misunderstood. It is not a species of tree. It is not simply a fragrant hardwood. It is the result of a pathological process.

How agarwood forms

Trees of the genus Aquilaria, and to a lesser extent Gyrinops, grow across South and Southeast Asia. In their healthy state, the heartwood of these trees is pale, light and essentially odourless. It has no commercial fragrance value whatsoever.

When the tree is wounded — by physical damage, insect attack, or more importantly by fungal infection entering through that damage — it responds by laying down a dense, dark oleoresin in the affected tissue. This resin is the tree's defensive response. It is also agarwood.

The process is slow. Meaningful resin accumulation takes years, and in wild trees often decades. Only a minority of trees in any given stand will be affected at all, and of those, only a fraction will have developed resin dense enough to be commercially useful.

Wood, oil, and the difference between them

Agarwood reaches the market in two principal forms. The first is the wood itself, sold as chips or larger pieces, graded by resin content and burned directly on charcoal or an electric heater. The second is the distilled oil, produced by soaking and then hydrodistilling lower-grade resinous wood.

The economics run in a particular direction: the highest-grade wood is almost never distilled, because it is worth more sold as wood. Oil is generally made from material that would not command a premium in chip form. This is not a criticism of oil quality — it is simply how the market allocates the raw material.

Why distillation practice matters so much

Agarwood oil varies more by distillation practice than almost any other natural material. Wood is typically soaked in water for days or weeks before distillation, and the duration of that soak, the material of the still, the length of the distillation run and the fractions collected all leave a clear signature in the finished oil.

A long soak produces the fermented, barnyard, intensely animalic character that some markets prize and others find unpleasant. A shorter soak gives a cleaner, sweeter, more woody-resinous result. Neither is correct in the abstract; they are different products serving different traditions.

CITES and the legal position

All Aquilaria species are listed on CITES Appendix II. This is a direct consequence of over-harvesting: wild populations across the natural range have been severely depleted by decades of extraction driven by exactly the scarcity described above.

Appendix II listing means international trade requires an export permit from the country of origin. Most destination countries additionally require import documentation. This applies to the genus, not to the harvesting method — plantation-grown agarwood still requires a permit.

Plantation agarwood

Cultivated Aquilaria, deliberately inoculated to induce resin formation, now accounts for a growing share of legitimate supply. Plantation material is often criticised as inferior to wild agarwood, and for the very finest wild resin that criticism has some basis.

But the comparison is not the relevant one. The realistic alternative to plantation agarwood is not fine wild agarwood — it is no agarwood, or illegally harvested agarwood. Plantation sourcing is also the only route to a documented, repeatable chain of custody, which for any buyer operating at commercial scale is decisive.

What to ask when buying

• Which species? Aquilaria crassna, A. malaccensis and A. sinensis differ in profile.
• Wild or plantation, and can the supplier evidence it?
• What is the permit position for your destination country, specifically?
• How long was the wood soaked before distillation, and how long was the run?
• Is there a GC-MS for the specific lot being offered — not a different one?

A supplier who can answer all five without hesitation is a different proposition from one who answers with adjectives.