How to burn agarwood chips

Agarwood releases its fragrance through heat, not flame. The aim is to warm the resin enough to release its aromatic compounds without scorching the wood. Char it and you get a harsh, smoky smell that hides the resin. Warm it gently and you get the layered, changing scent agarwood is valued for. Both traditional charcoal and electric heaters can do this well.

Warm, do not burn

Agarwood's aromatic compounds, the sesquiterpenes and chromones described in how agarwood resin forms, are released as the wood warms, well before it would burn. Heat it gently and they come off gradually, which is why the scent changes during a session. Heat it too hard and the wood itself starts to combust, adding smoke and burnt notes. Most of the difference between a good session and a disappointing one comes down to managing that heat, not the price of the equipment.

What you need

• A heatproof burner or censer.
• For charcoal: fine ash to fill the burner, a charcoal, a lighter and metal tongs.
• For electric: an electric agarwood or incense heater with adjustable heat.
• A mica plate, which sits between the heat and the wood and slows how fast heat reaches it.
• One or two small slivers of agarwood. Thin pieces release scent more evenly than thick chunks.

The charcoal method, step by step

Fill the burner loosely with ash. Light the charcoal, ideally in a separate dish, and let it burn until it is glowing inside and covered with a light grey ash, which can take several minutes. Quick-lighting charcoal discs can smell of their ignition chemicals, so letting them burn through first matters. Bury the charcoal in the ash, leaving a thin layer over it, and make a small vent down towards the coal.

Set a mica plate over the vent and place a sliver of agarwood on it with tongs. Within a minute or so you should notice the scent. If it is faint, move some ash away so the heat is stronger. If you smell burning, or see smoke rising from the wood itself, remove the sliver and add more ash. As the scent fades, the wood can be turned or replaced.

The Japanese way

The charcoal and ash method above is close to how incense wood is appreciated in kōdō, the Japanese way of incense covered in agarwood in Japanese culture. There, the charcoal is buried in a carefully shaped mound of ash in a small cup, a vent is opened to the coal, and a small mica plate called a gin-yō, "silver leaf," is set over it with a tiny piece of wood on top. The aim is the same: steady, gentle heat that releases scent without smoke.

The electric method, step by step

Electric agarwood heaters warm a small plate with adjustable heat, so there is no charcoal, no ash and, used correctly, little or no smoke. Place a mica plate on the heating surface if the heater does not already have one, set a sliver of wood on top, and start on the lowest setting. Wait a few minutes before raising the heat a step at a time until the scent comes through. Settings and temperatures differ between models, so learn your own heater rather than following a single number.

Electric heating is often described as cleaner and gentler, with less risk of burnt notes, which makes it a good place for beginners to start. Some enthusiasts feel charcoal brings out more from certain woods. The trade-offs are covered in electric burner vs charcoal.

Adjusting as you go

Adjusting during a session is normal. Pieces vary in density and resin, so a setting that suits one sliver can scorch a more resinous one. If the scent turns sharp or smoky, lower the heat or add ash. If it is barely there, raise it slightly. Very resinous wood generally needs less heat than plain wood.

Ventilation and safety

Burning charcoal gives off carbon monoxide, so always use it in a ventilated room and never in a closed space. Never leave lit charcoal or a switched-on heater unattended, and remember that charcoal and ash stay hot long after they stop glowing. Keep burners on a heatproof surface, away from anything flammable and out of reach of children and pets. If you are sensitive to smoke, an electric heater on a low setting is the gentler option.