Two resins share the name benzoin. They come from different trees in different countries, they contain different acids, they smell different, and they are priced differently. Shops that sell “benzoin” without saying which one are, at best, selling Sumatra.
The trees and the places
Siam benzoin is tapped from Styrax tonkinensis, a fast-growing tree of the uplands of northern Laos, with smaller production in Vietnam and historically Thailand (Siam gave the resin its trade name, though Laos has long been the real source). The tree is planted in rotation with upland rice; it is tapped from about seven years of age and abandoned after ten to fifteen years of production.
Sumatra benzoin comes from Styrax benzoin and the closely related S. paralleloneurus, grown in the Batak highlands of North Sumatra, Indonesia, around Lake Toba. Here benzoin, called kemenyan, is an old smallholder economy with its own grading vocabulary. Trees are tapped for decades.
Chemistry: benzoic versus cinnamic
The chemical split is clean enough to be used as an identity test in pharmacopoeias.
- Siam is a benzoic acid balsam. Its main constituents are coniferyl benzoate (the bulk), free benzoic acid, benzyl benzoate and vanillin. Cinnamic acid is essentially absent.
- Sumatra is a cinnamic acid balsam. Alongside coniferyl and cinnamyl esters it contains substantial free cinnamic acid, cinnamyl cinnamate (“styracin”), benzoic acid, benzyl benzoate and vanillin, plus styrene in trace amounts.
That single difference, cinnamates or not, explains the scent, the colour, the burning behaviour and most of the price gap.
Appearance
| Siam | Sumatra | |
|---|---|---|
| Form | Loose tears, sometimes agglomerated | Compact blocks, “almond” tears embedded in a darker matrix |
| Colour | Ivory, yellow, orange-amber; milky when fresh | Greyish to reddish brown outside, pale inclusions inside |
| Fracture | Glassy, milky-white interior | Duller, granular |
| Texture in the hand | Brittle, warms and softens slightly | Harder, more bark and grit in lower grades |
Scent
Siam on a warm blotter is sweet, creamy, vanillic and faintly almond-like, with a dry powdery finish. It has very little smoke or spice. It is the benzoin that perfumers mean when they say “benzoin”.
Sumatra is warmer and rougher. The cinnamates bring a spicy, honeyed, storax-like warmth and, on charcoal, a pronounced smokiness. Some batches carry a faint sourness. It is closer to tolu balsam than Siam is, and in incense that is often exactly what is wanted.
Grades
Both origins are sorted by hand. Trade names vary, but the logic is the same: bigger, cleaner, paler pieces with no bark cost more.
- Siam: graded by tear size and colour, roughly first (“almonds”, large pale tears), second (smaller tears), third (siftings, dust, agglomerated pieces). Perfumery buys mostly firsts and seconds and extracts them into resinoid and absolute.
- Sumatra: Indonesian grading distinguishes large clean pieces (kemenyan mata, “eye” grade), medium, and low grades made of scrapings and bark (tahir, jurur and other local terms). Church incense makers and pharmacies buy across the range; the pale inner tears go to better blends.
Which to buy
- For perfumery, tinctures meant to smell of vanilla, or incense where sweetness is the goal: Siam.
- For church-style blends, kyphi-type mixtures, bakhoor and anything that wants a spicy, smoky base: Sumatra.
- For tincture of benzoin as a skin protectant: pharmacopoeias historically specified Sumatra, and most compound tinctures are still made from it.
Telling them apart at home
Warm a small piece on a spoon over a candle. Siam melts to a clear amber and smells sweetly of vanilla; Sumatra darkens, smokes sooner and smells of cinnamon-tinged balsam. Under a hand lens Sumatra shows its pale tears set in darker resin like almonds in nougat. And read the label: any honest seller will name the species.
Frequently asked questions
Which benzoin is better, Siam or Sumatra?
Neither is better; they are different. Siam is cleaner, sweeter and more vanillic and is preferred in fine perfumery. Sumatra is warmer, spicier and smokier, cheaper, and better suited to incense blends and tinctures where its cinnamic character is welcome.
Why is Siam benzoin more expensive?
Smaller production, a single main origin (Laos), hand-sorted tears rather than blocks, and steady demand from perfumery. Sumatra benzoin is produced in much larger volume in Indonesia and traded in block form.
Can Sumatra benzoin be sold as Siam?
It happens. Dark colour, a spicy storax-like smell and a block rather than tear form are the giveaways. Genuine Siam tears are pale, brittle and smell cleanly of vanilla.
Sources & further reading
- benzoin
- siam
- sumatra
- grades
