Definition
Fractionation, also called fractional distillation, separates the constituents of an essential oil by boiling point. The material is heated under vacuum at successive temperatures, and each step yields a distinct fraction, a subset of the natural matrix isolated for its olfactive or regulatory value.
Technical process
Vacuum distillation lowers boiling points and protects fragile compounds from thermal damage. The lightest fractions, rich in esters and monoterpenes, come off first; heavy sesquiterpenes remain at the bottom of the column (source: Essential Stills). Major fragrance industrials, including Givaudan, Firmenich, Robertet and Mane, operate dedicated columns.
Use in perfumery
Fractionation serves three main purposes:
- Isolating vetiver fractions in heads, hearts and bases, to recover the smoother vetiverol portion as a woody fixative.
- Obtaining a furocoumarin free bergamot (FCF, bergaptenless) by removing phototoxic bergaptene, a prerequisite for cosmetic use under IFRA standards (source: AromaWeb).
- Producing the grades of ylang ylang: extra, then I, II, III. The extra concentrates light floral top notes for fine fragrance, while the III, richer in sesquiterpenes, serves as a base note.
Sources
- Essential Stills, Fractionation (Fractional Distillation) of Essential Oils (accessed 4 June 2026)
- Fragrantica, Ylang Ylang, the Flower of Flowers (accessed 4 June 2026)
- AromaWeb, Bergamot vs. FCF Bergamot Essential Oil Explained (accessed 4 June 2026)
- Nature's Gift, Ylang ylang Fractional Distillation (accessed 4 June 2026)