Gỗ hồng · một cây Amazon và linalool

A large tree in the Amazon forest. Logs one metre long floated downriver to the distillery. About one percent oil by weight of wood, and in that oil, 78 to 92 percent is a single molecule: linalool.

One Trunk for One Batch of Oil

Rosewood oil does not come from flowers, leaves or fruit. It sits in the wood. To get the oil the tree must be felled. As FAO describes it, after felling the trunk is cut into logs about one metre long, carried to the riverbank and stockpiled. When the river is high enough the logs are floated down to the distillery, chipped, and steam distilled. Each tree yields about one percent oil by weight of wood.

One percent means a tonne of wood gives about ten kilograms of oil. That number explains everything that followed. Every batch of oil stands for a number of lost trunks, and those trunks grew in wild forest, not in plantations.

The tree is Aniba rosaeodora, of the laurel family, related to cinnamon, bay laurel and massoia. It grows in the Amazon forest in Brazil, Peru, Guyana and French Guiana. The name rosewood comes from the smell of the wood, which recalls rose; it has nothing to do with the furniture timbers that share the English name.

Commercial production began in the nineteenth century, mainly around Manaus in the state of Amazonas. Since the 1960s nearly all world production has come from Brazil; other regions produce only insignificant amounts.

Aniba rosaeodora and CITES Appendix II

Decades of harvesting by felling whole trunks left their mark on the species. IUCN lists Aniba rosaeodora as Endangered. The Brazilian government has enacted regulations to conserve the species, but enforcement has been difficult.

In 2010, at CoP15, Aniba rosaeodora was added to CITES Appendix II. Appendix II covers species not necessarily threatened with extinction now but which may become so unless trade is closely controlled. The listing covers wood and essential oil: international trade in bulk rosewood oil requires export and import permits.

There is a detail in how it applies. According to the Lê Mai library, the legal limits target oil in bulk form; finished products packaged for retail are exempt. Control therefore sits mainly in the trade of raw material between countries, where the oil is still in drums and cans.

The library's certifications page places CITES alongside organic and fair trade schemes, but notes one difference: organic is voluntary, while for species on a CITES appendix, paperwork becomes an obligation under international law. With rosewood, the first question about a bottle is not how it smells but what its documents say.

Linalool: A Soft Floral Wood

The molecule that makes up most of rosewood oil is linalool, a monoterpene alcohol with a molecular weight of about 154. Its smell is described as soft floral, lightly woody and faintly spicy; one of the most classical floral notes in perfumery. The rest of rosewood oil is small amounts of alpha terpineol, 1,8-cineole and geraniol.

Linalool occurs in more than 200 commercial essential oils: neroli, bergamot, clary sage, lavender. But few sources are as concentrated as rosewood. That is why, in classical perfumery and eau de Cologne, rosewood oil was an important heart note: a clean, soft, almost transparent floral base for other notes to rest on. Linalool is also an isomer of geraniol and nerol, and one of the most heavily used constituents in the fragrance industry, even though it is abundant in nature. When the rosewood supply narrowed, the industry was not short of linalool; what it lacked was a natural linalool with clear documents.

Linalool has two optical isomers. The (R) form, also called licareol, dominates in rosewood and ho wood. The (S) form, also called coriandrol, dominates in coriander seed. The two smell slightly different, and the ratio between them is a fingerprint of where a linalool came from.

On safety, pure linalool is almost unreactive on skin, but when it oxidises it forms hydroperoxides that can sensitise. Linalool is on the EU list of fragrance allergens that must be labelled. Every linalool rich oil therefore needs a dark bottle and a tight cap, and should not be kept long after opening.

Ho Leaf and Other Sources of Linalool

If linalool is found in many places, the ethical question of rosewood has an answer. The main replacement is the camphor tree, Cinnamomum camphora. The species has many chemotypes: a 2023 survey of 974 trees across 13 Chinese provinces identified six main types, one of them rich in linalool.

The linalool type gives ho leaf oil, sometimes called ho wood oil even though it does not come from the wood. The oil is distilled mainly from leaves and twigs, with no need to fell the trunk. Linalool makes up about 67 to 91 percent, close to rosewood; the rest includes 1,8-cineole, nerolidol and traces of safrole and methyleugenol. Jiangxi province alone has more than 10,000 hectares of planted camphor.

Ho oil is also the main source of natural linalool as an isolate: the linalool is separated from the rest of the oil by fractional distillation, and the molecule itself is not altered. Linalool isolated from ho may keep a faint camphor note, a trace of its parent tree.

A third source is coriander seed. Coriander seed oil contains 59 to 88 percent linalool, but mainly in the (S) form, so it smells warmer, with a citrus and spice edge. France, India and the Netherlands are the main producers. These three sources show that the floral wood of rosewood need not be paid for with an Amazon trunk.

Proof of Origin for One Bottle

A small bottle labelled rosewood can hold three different things: true Aniba rosaeodora oil, ho leaf oil, or linalool with a few additions to make it resemble the real thing. To someone who does not smell often, all three are fairly close. Paperwork is what tells them apart.

For Aniba rosaeodora oil in bulk, a CITES export permit from the producing country and an import permit are the first condition. Next comes the batch certificate of analysis: the full Latin name, country of origin, lot number, and a gas chromatography table showing the composition. The two documents that usually travel with a bottle of oil, the certificate of analysis and the safety data sheet, are read more closely in two sheets of paper that travel with a bottle of oil.

Chiral analysis goes deeper. Plants usually make one isomer in excess, while ordinary synthetic linalool is a fifty to fifty racemic mixture. Rosewood and ho oils are mainly the (R) form. A sample with a near even ratio of the two forms suggests synthetic linalool; a sample rich in the (S) form suggests linalool from coriander.

On a retail label the minimum worth looking for is the Latin name. Aniba rosaeodora and Cinnamomum camphora are two trees of the same laurel family but different genera, with two different supply stories. A bottle that states which one it is has already answered the first question.

Rosewood on a Blotter

Dip a blotter into rosewood oil and the first impression is floral, bright and clean, with almost no sharp edge. After a few minutes a soft wood appears beneath the flower, with a light spice at the rim. It is not heavy, not cloyingly sweet, and it leaves fairly quickly compared with true woody materials such as sandalwood.

This reflects the chemistry. Linalool is a small molecule that evaporates in the middle range; rosewood oil is therefore a wood oil that behaves more like a floral heart than a base. Ho leaf oil on the next blotter may show an extra streak of camphor and cineole in the first minutes, then settle.

In a formula both play the same role: softening edges, bridging citrus and flower, giving a bright and airy middle. The difference between them is nuance, not function. And for a floral wood note with such a role, the difference in origin is far larger than the difference in smell.

Rosewood remains on the market, with CITES paperwork. Ho oil sits beside it, from the leaves and twigs of a planted tree. Choosing between the two bottles is choosing between two supply routes for almost the same molecule.

One percent oil in a trunk.

The same molecule in the leaves of another tree.

The remaining question lies on the paper that travels with the bottle.