How to test agarwood authenticity at home

Agarwood is valuable, judged largely by eye and nose, and easy to imitate with cheap wood, dye and fragrance. Researchers at the Royal Botanic Gardens, Kew, examining suspected agarwood seized by UK Border Force, found pinewood that had been dyed and fragranced to pass as agarwood, and some "agarwood" that contained no plant material at all. Simple checks will not catch everything, but they will catch a lot of that.

This guide covers checks you can run with no equipment beyond a glass of water and a burner. The tricks they are meant to catch are covered in fake oud: what to look for.

Why test at all

Most buyers cannot check a seller's claims about species, origin or grade directly. What they can check is whether a piece behaves like resinous wood at all. A few minutes of looking, weighing and smelling will not expose a skilled fake, but it will often expose a careless one, and it costs nothing.

Look at the grain

Resin builds up unevenly as a tree responds to wounding and infection, as described in how agarwood resin forms. Genuine agarwood therefore usually shows dark resin running through paler wood in irregular streaks, patches and veins, with no repeating pattern. Cut or broken edges are worth looking at closely, since resin should run into the wood rather than sit on top of it.

Wood darkened to imitate a high grade often looks too even: the same flat black or dark brown over the whole surface, with no paler wood showing through anywhere. A coating may also sit on the surface with an unnatural gloss, or rub off on a damp white cloth. Use a magnifier if you have one.

Weight and the sinking test

Resin is denser than the surrounding wood, so heavily resinated agarwood feels heavy for its size. Anything denser than water, which is about one gram per cubic centimetre, will sink. Drop a small piece into a glass of room temperature water and give it a minute.

A floating piece is not proof of a fake. Plenty of genuine agarwood, including most plantation material, has too little resin to sink. The problem is a piece sold and priced as sinking grade that floats. The reverse also matters: a sinking piece is not proof of quality, because wood can be injected with oil or other material to raise its density. The trade's use of sinking as a grade marker is covered in how agarwood is graded.

The cold smell

Unheated, genuine agarwood usually smells faint: woody, slightly sweet or resinous, sometimes barely noticeable in lower grades. A piece that smells strongly of perfume straight from the packet, or has a sharp solvent or alcohol edge, is a warning sign. It often means the wood has been sprayed or soaked with fragrance to make up for a lack of resin. A lighter touch of fragrance can be harder to notice, so treat a clean cold smell as neutral rather than reassuring.

Gentle heat

Agarwood is traditionally warmed rather than burned, and warming is also the more revealing check. Place a thin sliver on an electric incense burner or on a mica plate over a charcoal, at a low setting. Avoid a direct flame, since any wood held in a flame produces smoke that hides the scent you are trying to judge. How to do this properly is covered in how to burn agarwood chips.

Resinous agarwood usually releases a scent that changes over several minutes as it warms, and on a resin-rich piece you may see the resin bubble at the surface. Wood treated with fragrance often smells harsh, acrid or sour when heated, or gives a strong first impression that quickly collapses into plain burning wood. Scent is subjective, and a well-made fake with good fragrance oil can pass a casual sniff, so this check works best alongside the others.

The warm water check

This one is mainly for beads and carvings, where dye is a common concern. Soak a bead or small piece in a cup of hot water for a few minutes. If colour leaches into the water, the piece has probably been dyed. A thin film of oil on the surface is less clear-cut, since resinous wood can release some oil of its own. Ask the seller before testing a piece you have not bought, and do not do this with valuable carvings you want to keep in perfect condition.

What home tests cannot tell you

No home test can tell you which species a piece came from, which country it grew in, or whether it was wild or plantation grown. Those claims rest on documentation and the seller's credibility, covered in questions to ask before you buy oud. More sophisticated fakes, such as low-grade wood injected with oil under pressure, can pass the sinking test and sometimes the heat test as well.

For expensive purchases, laboratory methods are the stronger option. Chemical profiling such as GC-MS can show whether the compounds typical of agarwood are present, and researchers are developing faster tools: the Kew team, for example, tested near-infrared spectroscopy as a quick screening method for suspected agarwood. Even lab results confirm what a sample contains rather than where it came from, so documentation still matters.