How is incense burn? To understand the different components present in incense smoke, we must first understand what incense is make of. Incense is traditionally create with plant materials, such as different types of wood, herbs and resins, as well as essential oils. Incense may be direct burning—which typically comes in the form of incense sticks or cones—or indirect burning. Indirect burning incense can be powder or it may come in the form of a paste or collection of raw materials. This type of incense is burned by putting it on top of a combustible surface, such as light coals or glowing embers. When you burn anything—tobacco, incense, firewood or even food—you are facilitating a process call combustion. In the case of burning incense, combustion is a chemical reaction between the fuel source (incense) and oxygen that results in a gaseous product (smoke).