Exploring the Science Of Scent at the Royal Institution

The solid Victorian walls of London's Royal Institution have echoed all manner of profound scientific questions over the last two centuries, except perhaps the one asked on Thursday night: How is an idea turned into a fragrance? This was the central theme of the third and final Science Of Scent presentation conducted by Will Andrews, an Evaluator at the Fragrance Design Team of Procter & Gamble Prestige.

In simple terms, Andrews' answer was teamwork, time and obsessive dedication, although he also made it clear over the course of the enthralling evening that few aspects of the world of perfumery can be described as simple.

Regardless of whether it is eventually picked up by one of P&G's clients, Andrews explained that a fragrance must start with a compelling idea. Many of our most evocative scent associations are created when we are very young, which is why perfumers often look to their childhood for a conceptual starting point.

As he distributed smelling strips dipped in a cut-grass accord, Andrews stressed that the entire team responsible for the creation of a scent must remain faithful to this core idea throughout the design process. This is made difficult by three main obstacles: the intense subjectivity of our responses to smell, the lack of a simple, universal measure of odour, and the absence - in any culture - of a specific olfactory language which does not resort to metaphor or analogy.

Convincing evidence of the magnitude of these obstacles was provided when Andrews asked the audience to describe the cut-grass accord using the vocabulary of the non-olfactory senses. Responses ranged from "smooth" and "spiky" and from "white" to "brown".

There is also the not insignificant - but more widely recognised - issue posed by the number of materials available to the modern scent-maker. Jose Maria Velazquez, a Senior P&G Perfumer with 20 years' experience in the field, was invited to explain how, out of the 5000 or so ingredients at his disposal, he may become quite familiar with about 2500, of which he will tend to rely on around 1500. As Andrews stated, the perfumer's most important organ is not the nose, but the brain, within which he or she must strive to construct an intricate "memory palace" of odours. It is also vital to move away from the notion of 'good' and 'bad' smells and learn to appreciate each ingredient for its own unique effects and characteristics.

Despite these challenges, new fragrances are, of course, created on a regular basis, and Andrews briefly described one typical journey from an idea in someone's mind to a product in a department store. Several years ago, whilst hiking in Maine's Acadia National Park, a perfumer suddenly entered a clearing and was faced by the waters of the Atlantic Ocean. That one particular moment - charged with the scent of pine trees, the mossy forest floor and the sting of sea water - remained in his mind and prompted him to recreate it in his lab. At the same time, P&G were commissioned to create a fragrance, for which the design team thought the 'Acadia accord' might be suitable. 3 years and 254 iterations later, the accord sported a familiar green apple top note and became the original Hugo from Hugo Boss.

Andrews also used this anecdote to highlight the role played by visual imagery in influencing the success of a fragrance. He conceded that, on the one hand, the photos and short films promoted by the fashion houses fulfill a basic advertising function. However, he also maintained that the 'right' marketing campaign may actually act as a bridge between the perfume and the potential wearer, enabling him or her to make the associations and connections that will enable a full appreciation of what may otherwise seem an inaccessible, 'difficult' scent.

According to Andrews, even though an individual perfumer may be highly introspective, the whole process of perfume creation at P&G would not be possible without a collective effort, in much the same way as the contributions of various people lead to the production of a film. "We are not in the business of making art," he said, "we are in the business of making scented images."

After his lecture, Andrews asked the audience to split into groups, each of which was assigned to one of three P&G perfumers - Velazquez, Julian Plos and Peter Malton - who provided a breakdown of the creation of one of their own scents. Inspired by the Japanese incense ceremony called Kodo, Plos' fragrance was based on a frankincense, orris and benzoin accord, lifted by orange flower absolute. These individual ingredients were passed around the group, prompting a wide variety of queries and observations.

The evening ended with the buzz of countless discussion topics, from differing cultural perceptions of smells to the use of headspace technology to create accords based around the experience of playing a computer game. Andrews stated that his main goal was to use the event to "lift the lid" on the world of perfumery. Judging from the surprisingly wide age range of the audience and the astuteness of their questions, he may well have succeeded.