Julia Lawless - Encyclopedia of Essential Oils - The complete guide to the use of aromatic oils in aromatherapy, herbalism, health and well-being.

The essential oil content in a blend should usually be between 1 per cent and 3 per cent depending on the type of disorder; as a general rule, physical ailments demand a stronger concentration than the more emotional or nervous conditions. Some oils, such as the high-quality florals including rose and jasmine, have more diffusive power than most other essences – this means that a very small percentage is all that is needed to have a powerful effect, or to influence the character of an entire blend.

The proportions of each essential oil in a blend can also be vital to the effectiveness of the remedy as a whole (many aromatherapy books contain exact recipes for specific disorders). Some oils blended together have a mutually enhancing effect upon one another, so that the whole is greater than the sum of the parts: for example, the anti-inflammatory action of chamomile is supported by being mixed with lavender. When the blended oils are working harmoniously together, then the combination is called a ‘synergy’. ‘In order to create a good synergy, you must take into account not only the symptom to be treated but also the underlying cause of the disorder, the biological terrain, and the psychological or emotional factors involved.’ 17

This is very much the conclusion that Madame Maury reached when she prescribed an IP (or Individual Prescription) for her patients, in which the blended essences were matched not only to their physical requirements, but also to their circumstances and temperament.

In general, oils of the same botanical family blend well together. Also those which share common constituents usually mix well, such as the camphoraceous oils containing a good percentage of cineol, which includes all the members of the Myrtaceae group (eucalyptus, tea tree, cajeput, myrtle, etc.) but also many herbs including spike lavender, rosemary and Spanish sage. Most floral fragrances blend well together, as do the woods, balsams, citrus oils and spices, etc. Rosewood and linaloe combine well together, although they belong to different botanical families, since they both contain a high proportion of linalol and linalyl acetate.

Some oils such as rose, jasmine, oakmoss and lavender seem to enhance just about any blend, and can be found (mainly in an adulterated form) amongst the ingredients of most commercial perfumes – ‘no perfume without rose’.

Some combinations, on the other hand, have an inhibiting power over one another. Essences with a predominance of aldehydes (such as citronella oil containing citronella!), those with mainly ketones (such as sage containing thujone) and those with high amounts of phenols (such as clove oil containing eugenol), when combined with each other tend to ‘pull’ in different directions. However, knowing the precise chemical make-up of each oil is not necessary for creating a good synergy; it is also a matter of getting to know the ‘character’ of each essential oil and trusting the intuition.

In the nineteenth century, a Frenchman called Piesse instigated a new approach to perfumery work by classifying odours according to the notes in a musical scale. He transposed the idea of musical harmony into the realm of fragrances where the corresponding notes to each scent formed perfectly balanced chords or harmonics when they were combined together.

The purist vision of Piesse has long since been discarded but continues to provide inspiration in perfumery work today since the oils are still divided into ‘top’, ‘middle’ and ‘base’ notes.

The top note has a fresh, light quality which is immediately apparent, due to the fast evaporation rate.

The middle note is the heart of the fragrance, which usually forms the bulk of the blend, whose scent emerges some time after the first impression.

The base note is a rich, heavy scent that emerges slowly and lingers. It also acts as a fixative to stop the lighter oils from dispersing too quickly.

Ylang ylang is said to be a well-balanced perfume oil in its own right. It could be described as having a very powerful sweet floral top note, a creamy-rich middle note, and a soft floral, slightly spicy base note.

For the sake of simplicity, each essential oil is also classified in this way according to its dominant character – although there are many different opinions on the matter! The following list provides nothing more than a general idea:

Top notes tea tree, eucalyptus, mandarin, lemon, basil

Middle notes geranium, lavender, marjoram, rosewood, rosemary

Base notes patchouli, rose, jasmine, benzoin, frankincense, myrrh

A well-balanced perfume is said to contain elements from each of these different categories, the quantities of each determining whether it is a heavy oriental-type scent or a light floral aroma. Although this theory is used primarily in fragrance work, the same principles can also be applied to aromatherapy and personalized remedies.

Creating a perfume or an individual fragrance is like painting a picture or making a meal: it needs the correct balance of colours or flavours, neither too sparse nor too crowded; it also generally has a theme. A perfume should have a focus around which other fragrances unite. For example, if we want to create an oriental fragrance or a heart-warming, elevating type of blend, then woody or musky oils and balsams will play a central role. The exotic perfume ‘Shalimar’ by Guerlain contains a predominance of such oils, containing among its ingredients Peru balsam, benzoin, opopanax, vanilla, patchouli, rose, jasmine, orris and vetiver as well as rosewood, lemon, bergamot and mandarin.

Home perfumes need not be so complex: rose and benzoin (base notes), rosewood (middle note) and bergamot (top note) would together make a pleasing combination with an uplifting, warming quality. Rosewood is an oil which can be used to round off sharp edges, as well as providing a good bridge between citrus and floral or woody-balsamic notes. The overall character of a perfume also benefits from unusual or diverse combinations which can help to give personality to an otherwise ‘flat’ fragrance. A floral fragrance with a hint of spice such as clove or cinnamon can add depth and interest, but the percentage of such additions is critical because they can easily upset the balance.

A skilled perfumier can identify some 30,000 different odours, but to begin with it is best to become familiar with a few common oils and develop from there. By initially keeping to a maximum of three or four oils per blend it is possible to keep in touch with their individual scents and qualities, then slowly build up a personal vocabulary of odours.

Most commercial perfumes are diluted in alcohol; a typical eau de cologne contains no more than 3–5 per cent aromatic material, usually synthetic. Home-made perfumes are best made up simply of pure essences, which last longer and may be used neat on the skin or in the bath, etc.

Personal experimentation is the only way to really find out what works, for the unique quality of essential oils is that they possess an array of therapeutic possibilities complemented by a vast spectrum of fragrances which can be mixed in endless combinations! In the words of John Steele:

Creative blending is an aesthetic alchemical process … learning to ‘listen through the nose’. To listen is to be receptive, to be empty. Every drop shifts the orchestration of olfactory vibrations, the ‘song of the blend’. A blend is not made at once, rather it evolves, it organically grows and interacts not only with the essential oils, but also with the blender. 18

Various stages of the alchemical process, including the appearance of the golden flower; from Mutus liber , 1702