Headspace is a method for capturing the scent of something without harming it. A clear enclosure is placed over a living flower, a piece of fruit or even an object, and the air inside — the "headspace" — is drawn through a trap that holds its fragrant molecules. In the laboratory, those molecules are identified and measured, usually by gas chromatography and mass spectrometry. Perfumers then use that analysis as a guide to rebuild the scent from available materials. Headspace is how perfume can smell of flowers that give no extract — lily of the valley, lilac, rare orchids — or of a flower as it smells on the plant rather than after picking.

Why it was needed

Traditional extraction — distillation, solvents, enfleurage — works on harvested material, and changes the smell in the process. Some flowers yield nothing usable; others smell quite different once picked, heated or extracted. See How Perfume Ingredients Are Extracted. Headspace lets chemists study the scent a living thing actually gives off, in place and at a chosen moment — a flower at dawn, at its peak, or at night.

How it works

  1. Enclose. A glass or inert plastic enclosure is placed gently around the flower or object.
  2. Collect. Air from inside is drawn through a small tube or trap containing an absorbent material, which holds the fragrant molecules. Sometimes this runs for hours.
  3. Analyse. In the laboratory, the trapped molecules are released and separated by gas chromatography, and identified by mass spectrometry. The result is a list of the molecules present and their relative amounts.
  4. Reconstruct. A perfumer uses the analysis as a starting point, choosing available natural and synthetic materials to recreate the impression — then adjusting by nose, because an analysis is not a smell.

Headspace does not bottle a flower. It gives the perfumer a map of where the flower’s scent lives.

A short history

Headspace methods were developed in the flavour and fragrance industry from the 1970s, as analytical instruments became sensitive enough to detect the tiny amounts of molecules in the air around a flower. Roman Kaiser, a chemist at the fragrance house Givaudan, was among its pioneers, applying it from 1975 to flowers in gardens and, later, to scents in tropical rainforests and other remote places. Other fragrance companies developed their own versions. The method also made it possible to study rare or protected plants without picking them.

What headspace has given perfume

  • Silent flowers. Flowers that give no extract — lily of the valley, lilac, gardenia, many orchids — can be recreated more faithfully. See Lily of the Valley in Perfume and Gardenia in Perfume.
  • Living freshness. The difference between a cut rose and a rose on the bush can be studied and evoked. See Rose in Perfume.
  • Places and things. Headspace has been used on wood, stones, sea air, fruits and spices — anything with a scent.
  • New notes. Analyses sometimes reveal molecules that inspire new materials.

What it cannot do

  • It cannot capture a scent in a bottle. The trap holds tiny amounts for analysis, not perfume.
  • It does not replace the perfumer. The list of molecules is a guide; some may be unavailable, unsafe or not permitted, and their effect in a perfume differs from their effect in a flower.
  • A "headspace" note is still a reconstruction. See Are Perfume Notes Real Ingredients?.

The wider process of making a perfume is described in How Is Perfume Made?, and the perfumer’s role in What Does a Perfumer Do?.

Common questions

Does headspace perfume contain the real flower?

No. Headspace analyses the flower’s scent; the perfume recreates it from other materials.

Why can’t you just extract the flower?

Some flowers give no usable extract, and extraction changes the smell of others. Headspace captures the scent of the living flower.

Is headspace used for anything except flowers?

Yes — fruits, woods, spices, foods, places and objects have all been analysed this way.

Who invented headspace?

It was developed by several researchers in the flavour and fragrance industry from the 1970s; Givaudan’s Roman Kaiser is among the best-known pioneers.

Sources

Roman Kaiser, Meaningful Scents Around the World: Olfactory, Chemical, Biological, and Cultural Considerations (Wiley-VCH, 2006), on headspace sampling of flowers and other scents. Kaiser’s application of the technique at Givaudan from 1975 is the date given in accounts of his work; the wider history of headspace is shared among several researchers and companies.

Further reading

For people who make perfume, RUŌOD Lab explains how to read an analysis report in GC-MS for Perfumers, and how a natural material is rebuilt from its constituents in Essential Oil Reconstitution. How headspace data becomes a working formula is described in Rebuilding a Scent from Headspace Data.