Trees have been bleeding aromatic resin onto the ground since long before anyone thought to burn it, and humans have been burning it for at least five thousand years. The family is large and the vocabulary is loose. This guide sorts it out and introduces the materials covered elsewhere on Benjuí.
Four kinds of thing
Resin in the strict sense is a solid or semi-solid plant exudate, insoluble in water, soluble in alcohol and oils, that softens with heat and burns with aromatic smoke. It is made of terpenoid and phenolic compounds. Pine resin, dammar, mastic and sandarac are pure resins.
Oleoresin is resin still carrying a good deal of its essential oil, so it is soft, sticky and strongly scented. Elemi, galbanum and fresh copal are oleoresins. They harden and lose fragrance as the oil evaporates.
Gum resin is a natural mixture of resin and water-soluble gum (polysaccharide). It partly dissolves in water, giving a milky emulsion, and burns with a lighter, brighter smoke than a pure resin. Frankincense, myrrh and opoponax are gum resins.
Balsam is a resin rich in benzoic or cinnamic acid and their esters. Balsams are often soft or liquid and have a characteristic sweet, vanilla-cinnamon warmth. Benzoin, storax, tolu and Peru balsam are true balsams.
Most incense and perfumery talk uses “resin” for all four. That is fine, as long as you know that frankincense will dissolve partly in water and elemi will not, and that benzoin will go sweet on the heater while dammar goes piney.
The materials
Balsams (sweet, vanilla-cinnamon)
- Benzoin — Styrax spp., Laos and Sumatra. Sweet, vanillic, powdery. The sweet base of church incense and amber perfumes.
- Storax (styrax) — Liquidambar spp., Turkey and Central America. Leathery, spicy, faintly floral.
- Tolu and Peru balsam — Myroxylon balsamum, South and Central America. Warm, cinnamon-vanilla, heavy.
Gum resins (the incense classics)
- Frankincense (olibanum) — Boswellia spp., Arabia, Horn of Africa, India. Lemony, resinous, peppery. Burns clean.
- Myrrh — Commiphora myrrha, Somalia, Ethiopia, Yemen. Bitter, warm, medicinal.
- Opoponax — Commiphora guidottii. Sweet myrrh; softer, more balsamic.
- Galbanum — Ferula spp., Iran. Green, sharp, resinous. Perfumery more than incense.
Resins and oleoresins
- Labdanum — Cistus spp., Mediterranean. Sticky, leathery, ambery, warm. The backbone of amber accords.
- Copal — Bursera, Protium, Hymenaea and others, Americas and Africa. Bright, citrus-pine. Mesoamerican ceremonial incense.
- Elemi — Canarium luzonicum, Philippines. Fresh, lemony, peppery.
- Mastic — Pistacia lentiscus, Chios. Clean, piney, faintly cedar. Chewed, cooked and burned.
- Dammar and sandarac — varnish resins that also burn cleanly and lightly.
- Dragon’s blood — Daemonorops, Dracaena. Red, faint, mostly used for colour and ritual.
And the two ambers
- Amber — fossil resin has almost no smell; “amber” in perfumery is an accord built from labdanum, benzoin and vanilla.
How they behave on heat
| Melts | Smoke | Character on heater | |
|---|---|---|---|
| Frankincense | Softens, bubbles | Light, white | Bright, lemony, clean |
| Myrrh | Softens slowly | Moderate, darker | Bitter, warm, medicinal |
| Benzoin | Melts to liquid | Heavy, sweet | Vanilla, then acrid if too hot |
| Copal | Melts fast | Moderate, white | Pine-citrus, brisk |
| Labdanum | Sticky liquid | Heavy | Ambery, leathery, animalic |
| Elemi | Melts fast | Light | Lemon-pepper, fresh |
| Storax | Already liquid | Heavy | Leather, spice, smoke |
The lesson every incense tradition learned independently: blend. Frankincense for lift and cleanliness, a balsam for sweetness, myrrh or labdanum for depth. See DIY resin incense blends.
How they behave in perfume
Resins are base notes and fixatives almost without exception. Their large molecules evaporate slowly and hold lighter materials back. Perfumers use them as extracts: resinoids (solvent-washed raw resin), absolutes (alcohol-purified resinoids) and, for gum resins and oleoresins, essential oils by steam distillation. Frankincense, myrrh, elemi and galbanum give good essential oils; benzoin, labdanum and the balsams do not distil well and are used as absolutes and resinoids. See Resins in perfumery.
A note on sustainability
Every material here is a smallholder or wild-harvested product from a specific landscape: the Dhofar hills, the Batak highlands, the Chios mastic villages, the Cistus scrub of Andalusia. Frankincense in particular is under pressure from over-tapping and land-use change in the Horn of Africa. Buying graded material from suppliers who name origin and pay for quality is the most useful thing a consumer can do.
Frequently asked questions
What is the difference between a resin and a gum?
A resin is insoluble in water and soluble in alcohol; it burns with aromatic smoke. A gum is water-soluble and does not burn aromatically. Many 'resins' sold for incense, including frankincense and myrrh, are gum resins: a mixture of both.
Which resin is best for incense?
Frankincense is the easiest and most universally liked. Myrrh, benzoin and copal are the next tier. Most traditions blend two or more, because each covers the others' weaknesses: frankincense burns clean but thin, benzoin is sweet but smoky, myrrh is deep but bitter.
Are natural resins safe to burn indoors?
In small amounts with ventilation, yes; people have done it for millennia. All incense smoke contains fine particles. Use low-heat methods where possible and avoid daily heavy use in unventilated rooms.
Sources & further reading
- resins
- balsams
- gum resins
- pillar
