What is oud?

Oud — also written oudh, ud or aoud, and known as agarwood — is the dark, resin-saturated heartwood of trees in the Aquilaria genus. A healthy Aquilaria produces none of it. The resin only forms where the tree has been wounded and a mould has taken hold, and the tree responds by flooding the injury with a dense aromatic compound.

So oud is not harvested from a tree the way sandalwood is. It is harvested from an injury.

Warm, dark and animal — closer to leather and smoke than to anything floral. Thai agarwood tends towards dry wood and a faint sweetness; Cambodian material is often rounder and more honeyed; Indian oud can read almost barnyard-like at first.

It is also one of the few materials that is genuinely divisive. First contact is often uncomfortable. Most people who end up loving oud did not like it immediately.

Roughly one Aquilaria tree in a hundred forms resin in the wild, and it takes twenty years or more before the wood is worth harvesting. The genus is listed under CITES Appendix II, so legal material travels with paperwork. Distillation then turns kilograms of wood into millilitres of oil.

The price is not a margin. It is a tree, two decades, an injury and a permit.

None. Oud is the Arabic word, agarwood the English one, and oudh, ud and aoud are transliterations of the same term. In Japan the material is called jinkō and used as incense rather than perfume.

As a base note. Oud sits at the bottom of a composition, under everything else, and it is still there when the top has gone. That is why an oud fragrance is judged after three hours rather than at the first spray.

Most fragrances sold as oud contain no agarwood at all, but a synthetic accord arranged to read as one. That is not a scandal — it is arithmetic. It does change how the fragrance behaves on skin.