Smoky-sweet, rubbery, with an organic-vegetal undertone. Less harsh than synthetic rubber, less acrid than tires. A milky, slightly fatty quality from the latex protein content. Smoked rubber sheets add a phenolic-creosote quality. Overall: warm, thick, organic — an industrial material with botanical origins.
Evolution over time
Immediately
Immediately
Rubbery-organic, milky, faintly sweet
After a few hours
After a few hours
Warm smoky-phenolic depth, fatty undertone
After a few days
After a few days
Persistent smoky-rubber residue
The Full Story
Caoutchouc is the raw, natural rubber obtained from the latex sap of Hevea brasiliensis. The word comes from the Quechua 'kawchu' (weeping tree) and refers specifically to unvulcanized natural rubber — a material with a particular sweet-smoky, organic smell quite different from the harsh chemical odor of synthetic rubber.
Fresh latex has a mild, slightly sweet, vegetal-milky smell. As it coagulates and dries, it develops the characteristic rubber odor — smoky, slightly acrid, with fatty-organic undertones from the polyisoprene degradation. The traditional smoking process used to cure rubber sheets (smoked sheets) adds a layer of phenolic, creosote-like character.
In perfumery, the caoutchouc note appears in avant-garde and industrial compositions. It provides an organic, vegetal-rubbery quality distinct from synthetic rubber or tire notes. The smoking process connection makes it compatible with smoky and leather accords.
Charles Goodyear discovered vulcanization (heating rubber with sulfur) by accident in 1839 when he spilled a rubber-sulfur mixture on a hot stove. Before vulcanization, natural caoutchouc was nearly useless — it melted in summer and cracked in winter.
Extraction & Chemistry
Extraction method: Natural caoutchouc is obtained by tapping the bark of Hevea brasiliensis and collecting the latex sap. The latex is coagulated with acid, washed, and dried — either air-dried (pale crepe) or smoked over wood fires (smoked sheets). No fragrance-grade extraction exists; the note is reconstructed in perfumery.
Molecular Formula
(C₅H₈)ₙ
CAS Number
9006-04-6
Botanical Name
Hevea brasiliensis
IFRA Status
No known restrictions
Synonyms
RUBBER · LATEX
Physical Properties
Odor Strength
Medium
Appearance
Colorless to pale yellow clear liquid
Specific Gravity
0.91 to 0.93 @ 25 °C
In Perfumery
Caoutchouc is a niche note used in industrial, leather, and avant-garde compositions. It provides an organic rubbery quality that is warmer and more vegetal than synthetic rubber. Built from smoky materials (cade oil, styrene traces), fatty-organic notes, and milky accords. Functions as a heart-to-base modifier. The phenolic smoke connection makes it compatible with leather and tobacco families.
