Composing perfumes

Perfume compositions are an important part of many industries ranging from the luxury goods sectors, food services industries, to manufacturers of various household chemicals. The purpose of using perfume or fragrance compositions in these industries is to affect customers through their sense of smell and entice them into purchasing the perfume or perfumed product. As such there is significant interest in producing a perfume formulation that people will find aesthetically pleasing.

The Perfumer

The job of composing perfumes that will sell is left up to an expert on perfume composition or known in the fragrance industry as the perfumer. They are also sometimes referred to affectionately as "the Nose" due to their fine sense of smell and skill in smell composition. The perfumer is effectively an artist who is trained in depth on the concepts of fragrance aesthetics and who is capable of conveying abstract concepts and moods with their fragrance compositions. At the most rudimentary level, a perfumer must have a keen knowledge of a large variety of fragrance ingredients and their smells, and be able to distinguish each of the fragrance ingredients whether alone or in combination with other fragrances. As well, they must know how each ingredient reveals itself through time with other ingredients. The job of the perfumer is very similar to that of flavourists, who compose smells and flavourants for many commercial food products. The composition of a perfume typically begins with a brief by the perfumer's employer or an outside customer. The customers to the perfumer or their employers, are typically fashion houses or large corporations of various industries. Each brief will contain the specifications for the desired perfume, and will describe in often poetic or abstract terms what the perfume should smell like or what feelings it should evoke in those who smell it, along with a maximum per litre price of the perfume oil concentrate. This allowance, along with the intended application of the perfume will determine what aromatics and fragrance ingredients can/will be used in the perfume composition. The perfumer will then go through the process of blending multiple perfume mixtures and will attempt to capture the desired feelings specified in the brief. After presenting the perfume mixtures to the customers, the perfumer may "win" the brief with their approval, and proceed to sell the formulation to the customer, often with modifications of the composition of the perfume. This process typically spans over several months to several years. The perfume composition will then be either used to enhance another product as a functional fragrance (shampoos, make-up, detergents, car interiors, etc.), or marketed and sold directly to the public as a fine fragrance. Alternatively, the perfumer may simply be inspired to create a perfume and produce something that later becomes marketable or successfully wins a brief. This usually happens in smaller or independent perfume houses.

Technique

Although there is no single "correct" technique for the formulation of a perfume, there are general guidelines as to how a perfume can be constructed from a concept.

Basic framework

Perfume oils usually contain tens to hundreds of ingredients and these are typically organized in a perfume for the specific role they will play. These ingredients can be roughly grouped into four groups: * Primary scents: Can consist of one or a few main ingredients for a certain concept, such as "rose". Alternatively, multiple ingredients can be used together to create an "abstract" primary scent that does not bear a resemblance to a natural ingredient. For instance, jasmine and rose scents are commonly blends for abstract floral fragrances. Cola flavourant is a good example of an abstract primary scent. * Modifiers: These ingredients alter the primary scent to give the perfume a certain desired character: for instance, fruit esters may be included in a floral primary to create a fruity floral; calone and citrus scents can be added to create a "fresher" floral. The cherry scent in cherry cola can be considered a modifier. * Blenders: A large group of ingredients that smooth out the transitions of a perfume between different "layers" or bases. Common blending ingredients include linalool and hydroxycitronellal. * Fixatives: Used to support the primary scent by bolstering it. Many resins and wood scents, and amber bases are used for fixative purposes. The top, middle, and base notes of a fragrance may have separate primary scents and supporting ingredients.

Fragrance bases

The perfume's fragrance oils are then blended with ethyl alcohol and water, aged in tanks for a minimum of 14 days and filtered through processing equipment to remove any sediment and particles before the solution can be filled into the perfume bottles. [citation needed] Instead of building a perfume from "ground up", many modern perfumes and colognes are made using fragrance bases or simply bases. Each base is essentially modular perfume that is blended from essential oils and aromatic chemicals, and formulated with a simple concept such as "fresh cut grass" or "juicy sour apple". Many of Guerlain's Aqua Allegoria line, with their simple fragrance concepts, are good examples of what perfume fragrance bases are like. The effort used in developing bases by fragrance companies or individual perfumers may equal that of a marketed perfume, since they are useful in that they are reusable. On top of its reusability, the benefit in using bases for construction are quite numerous: 1. Ingredients with "difficult" or "overpowering" scents that are tailored into a blended base may be more easily incorporated into a work of perfume 2. A base may be better scent approximations of a certain thing than the extract of the thing itself. For example, a base made to embody the scent for "fresh dewy rose" might be a better approximation for the scent concept of a rose after rain than plain rose oil. 3. The concept of a perfume can be relatively quickly roughed out from a brief for purposes of feedback by cobbling together multiple bases and presented. Smoothing out the "edges" of the perfume can be done after a positive responses to the perfume concept.

Reverse engineering

Creating perfumes through reverse engineering with analytical techniques such as GC/MS can reveal some of the formula for a particular perfume but most perfumes are difficult to analyze because of their complexity, particularly due to presence of essential oils and other ingredients consisting of complex chemical mixtures. However, "anyone armed with good GC/MS equipment and experienced in using this equipment can today, within days, find out a great deal about the formulation of any perfume... customers and competitors can analyze most perfumes more or less precisely." Recreating perfumes in this manner is very expensive, unless one has access to the same complex ingredients as the original formulators. Furthermore the deliberate addition of inert ingredients to obscure the formula makes identification of components difficult. Antique or badly preserved perfumes undergoing this analysis can also be difficult due to the numerous degradation by-products and impurities that may have resulted from breakdown of the odorous compounds. However, these ingredients and compounds can usually be ruled-out or identified using gas chromatograph (GC) smellers, which allow individual chemical components to be identified both through their physical properties and their scent.