Incense

This section covers the materials and where they come from, the history, the forms and equipment, the religious uses including Taoist ones, and two subjects that most writing on incense avoids: what burning it does to indoor air, and what demand for the finest material has done to the trees it comes from.

What is being burned

The central material is agarwood, a resinous wood produced when certain tropical trees are infected by a mould and lay down a defensive resin. Healthy trees do not produce it; the wood is a response to injury. It is dense, dark, and when heated releases a complex scent that is the basis of the whole tradition.

Sandalwood is the second pillar, a fragrant heartwood from India and Southeast Asia, sweeter and more even in scent, and used in far larger quantities. Beyond these come camphor and borneol, musk from deer, ambergris, cloves, frankincense and myrrh imported from Arabia and East Africa, and a long list of Chinese aromatic plants used in compounded recipes.

Most incense is not a single material. Traditional practice compounds many ingredients according to recipes, with binders, and the compounding is a craft in itself with its own literature.

Where it came from

Chinese incense culture depends on long-distance trade, and this is worth emphasising because it is often presented as purely indigenous. Agarwood comes from Southeast Asia and southern China; sandalwood from India and Indonesia; frankincense and myrrh from Arabia and the Horn of Africa; cloves from the Moluccas.

The maritime routes that carried these goods were among the most important trading systems in the pre-modern world, and Chinese demand for aromatics helped drive them. A Song dynasty official's incense burner might contain material from four different regions, transported by Arab, Persian, Malay and Chinese merchants over several years.

The main uses

Religious offering is the largest use by volume. Incense is burned before deities and ancestors in temples and homes, and the act of offering it is a basic unit of Chinese religious practice across Buddhism, Taoism and popular religion. In this context the burning is the point: the smoke rises, the offering is made, and the quality of the material matters less than the act.

Appreciation is a separate use with different priorities. Here a small piece of fine material is heated gently, often without burning, and the scent is attended to closely. The material is graded and discussed, and pieces are collected. This is a connoisseur's practice and it is where the expense lies.

Then there are practical uses that are easily forgotten: repelling mosquitoes, scenting clothes and bedding, masking smells, and marking time. Incense clocks, in which a trail of powder burns along a channel at a known rate, were a genuine timekeeping technology and were used in monasteries to regulate periods of practice.

The forms

Sticks, the familiar form, are relatively recent in the long history and are convenient rather than refined. Coils burn for many hours and are used in temples where continuous burning is wanted. Cones are simple and burn hot.

Two older forms are worth knowing. Seal incense uses a stencil to lay a continuous line of powder in a pattern, often a character or a maze-like design, which is lit at one end and burns slowly along its length. And the method of heating without burning places a small fragment of material on a thin plate of mica or metal above hot charcoal buried in ash, so that the material is warmed to release its scent without combustion. This last is the method used for appreciation, and it produces almost no smoke.

Vessels

The censer is a major category of Chinese metalwork and ceramics. Early forms include the mountain censer, a bronze vessel with a pierced conical lid modelled as a mountain peak, so that smoke emerges as if from a landscape of immortals. Later forms include the simple tripod censer in bronze or porcelain that became the standard.

A famous class of bronze censers is associated with the Xuande reign of the early fifteenth century, and genuine examples are extremely rare while pieces bearing the reign mark are extremely common. This is one of the largest bodies of intentional imitation in Chinese art, and almost every such censer you will see is later.

Appreciation requires additional tools: tongs, an ash press, a spatula for shaping ash, a pick, a small container for the material. These are made in sets and are themselves collected.

Incense and Taoism

Burning incense is a standard element of Taoist ritual and of daily temple practice. It functions as an offering, as a means of communicating a petition upward, and as purification of a space before rites. Ritual texts specify when incense is offered and what is said while offering it.

There are also more specific uses. Talismans are burned and the ash sometimes taken in water. Certain aromatics appear in the internal alchemical literature. And the phrase for the practice of daily devotion is literally to burn incense, in the same way that English religious language uses one act to stand for a whole practice.

At Wudang and other sites, visitors will be offered or sold incense at halls. Three sticks is the common offering. It is worth knowing that very large sticks and expensive bundles sold at tourist sites are a commercial development, and that the tradition attaches no additional merit to size.

The way of incense

There is a Chinese term corresponding to the Japanese practice of incense appreciation, and the relationship between them needs stating carefully. Japan developed a highly codified practice from the fifteenth century, with schools, formal procedures and elaborate listening games in which participants identify materials.

China had a genuine culture of appreciation, particularly among Song literati, with substantial written literature on recipes and materials. But it did not develop into a codified school-based practice, and the elaborate ceremonial versions offered today in China are largely a recent revival, reconstructed since the 1990s and drawing significantly on Japanese models.

As with tea, this does not make the practice worthless. It does mean that a demonstration presented as an unbroken thousand-year tradition is likely to be a few decades old in its present form.

The air quality question

This is regularly omitted and should not be. Burning incense produces fine particulate matter, carbon monoxide, and a range of volatile organic compounds including some known carcinogens. Measured concentrations in poorly ventilated rooms with burning incense are high, comparable to or exceeding those from cigarette smoke.

Studies of temple workers and of households that burn incense daily have found associations with respiratory symptoms and, in some studies, with certain cancers. The evidence is not uniform and confounding is difficult, but the direction is consistent and the mechanism is not mysterious.

The practical implications are straightforward. Ventilate. Do not burn incense in a small closed room. Reduce frequency and quantity if you use it daily. And note that the appreciation method, heating without combustion, avoids the problem almost entirely, which is one good argument for it beyond the aesthetic.

Where the material comes from now

Wild agarwood is severely depleted. The trees producing it are listed under international trade controls, several species are threatened, and the resin-bearing wood cannot be harvested without felling. Prices for the finest grades are extraordinary, and the incentive to cut remaining wild trees is correspondingly strong.

Cultivated and artificially inoculated agarwood now supplies most of the market, and quality varies. Indian sandalwood has been similarly overexploited and is now largely plantation-grown under strict control.

A buyer should know this. Cheap material sold as agarwood is almost never agarwood. Expensive wild-harvested material may be legally questionable. Plantation material is the responsible choice and much of it is good. Anyone selling large quantities of wild agarwood cheaply is selling something else.

What the pages beneath this cover

Six pages. If you only want to know what the three sticks of incense in a temple mean, go straight to the ritual page. If the materials themselves interest you, start with the page on aromatic woods.

Origins and History of Chinese Incense Culture follows three distinct roles: smoke as sacrifice, incense as an everyday refinement in the scholar's room of the Tang and Song, and a long simplification afterwards that came close to a complete break in the modern period. Much of what is called revival today was learned back, and parts of it were reconstructed with reference to Japanese practice.

Aromatic Materials and Fragrant Woods explains that agarwood is what a tree produces after injury rather than a species of timber, distinguishes wild resin from induced resin, and is direct about how much adulteration exists in this market and why prices vary by a factor of a hundred.

Forms and the Art of Appreciation sets out the practical difference between stick incense, seal incense pressed into a continuous line of powder, and indirect heating, where the material is never lit but warmed through a mica plate above charcoal. The third is the most demanding and the most revealing of the material itself.

Incense in Ritual and Temple Life covers what actually happens in a temple: why three sticks, the order of placing them, when to kneel, and which customs are only a few decades old. It also explains that oversized sticks and auctioned first incense have little traditional basis.

Incense, Meditation and Taoist Practice separates two claims. Incense as a timer and as an environmental cue is well attested. Incense as something that directly alters a mental state is not well supported. The page also raises the practical question of ventilation and smoke.

Further Reading and Practice suggests an inexpensive way to begin, the traps to avoid, and what to read in Chinese and English.

Key points

• Agarwood is a resin produced by injured trees rather than a normal wood, and it is the centre of the whole tradition.

• Chinese incense culture depended on long-distance maritime trade and was never purely indigenous.

• Religious offering is the largest use, appreciation is a separate connoisseur's practice, and practical uses including timekeeping are easily forgotten.

• Heating without burning is the method used for appreciation and produces almost no smoke.

• The codified Chinese way of incense offered today is largely a revival since the 1990s drawing on Japanese models.

• Burning incense produces high indoor particulat

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