THE THEORY & PRACTICE OF ESSENTIAL OIL BLENDING

• The synergistic blending of pure essential oils can be carried out for both aromatic and therapeutic purposes.


• A highly creative endeavour, blending can be guided by both one's intuition as well as classifications that align essential oils with their aromas and/or individual characteristics.


• Essential oils have been categorized based on their scent family (e.g. floral vs. woody), their evaporation rate (e.g. top note vs. middle note), and on their therapeutic properties (e.g. calming vs. energizing).


• Using a systematic and highly reflective process, the skills and understanding required to create balanced, harmonious, and pleasant blends can be developed and refined over time.

INTRODUCTION

Blending essential oils is a highly rewarding activity. Even though the sheer number of essential oils and the possibility of combinations can seem overwhelming, with the backing of some theory and a little bit of precision, intuition, and creativity, making your very own essential oil blends is a very achievable task. Whether the goal is to address a specific ailment or formulate an enchanting fragrance, this comprehensive guide outlines both the theory (Part 1) and practice (Part 2) of the basics of essential oil blending.

PART 1: THE THEORY OF ESSENTIAL OIL BLENDING

Why blend essential oils at all? Essential oils are volatile aromatic essences of plants that are naturally complex in their composition. This complexity not only forms the rich, unique aromas they exude and the properties they display, but it is also the reason behind the interesting results seen when two or more essential oils are mixed together. Simply put, when essential oils interact with one another, they can bring out superseding effects that cannot be reduced to any individual essential oil. In aromatherapy, this phenomenon is known as 'synergy'.

Synergy implies that essential oils are, broadly speaking, more powerful in combination than when they act alone. Much like how the musical notes of a compelling melody can come together to give rise to a beautifully poignant and visceral experience, the mixing of certain essential oils can release enticing fragrances and therapeutic effects that may be different to the individual characteristics of any one essential oil.

THE CLASSIFICATION OF ESSENTIAL OILS

Throughout history, aromas and essential oils have been grouped and classified in a myriad of different ways. These groupings help us understand the simple question: "Which essential oils blend well together?". Mixing together incompatible oils can give rise to a lifeless or otherwise unpleasant scent, and can even diminish its therapeutic performance. Making a perfectly balanced and harmonious blend, on the other hand, can be therapeutically powerful and also an extremely thrilling and rewarding experience.

There are three basic techniques (or models) for classifying essential oils that are perhaps the most popular. Each of these are outlined below.

Classification Based On Scent Family

In perfumery, scents are often described and portrayed using colorful fragrance or aroma wheels. These frameworks, such as the popular one developed by English historian Michael Edwards, attempt to group different scents into overarching 'families' based on their unique natures and perceptual sensations. An underlying proposition in this framework is that there are fundamental relationships between certain scent family members, such that some are more compatible than others when put together.

This same assumption can be applied to essential oil aromas. A simple scent family classification is shown in the table below:

A straightforward way of blending using this model is to pick essential oils within the same scent family. As the chemical identities of these oils are closely related, they should broadly be compatible with one another. Another technique is to pick essential oils from two scent families that are well-known to blend effectively together. These associations are also listed in the table above; so for example, you would expect Peppermint, which is a Minty oil, to blend well with a Citrus oil such as Grapefruit or a Woody oil such as Pine or Cedarwood.

Classification Based On Evaporation Rate

This technique categorizes essential oils using the analogy of a musical scale. In the 19th century, Septimus Piesse was an English perfumer who speculated that there were similarities in the ways in which humans experience both sounds and smells. A major chord, for instance, consists of a root note, a major third interval, and a perfect fifth interval. When these precise pitches come together in harmony, our brain registers a pleasing and balanced sound. Could the scents of essential oils work in the same way?

It was eventually uncovered that Septimus Piesse had some substance to his theory. Today, the perfume and essential oil industry commonly places essential oils into three overarching 'notes', each of which portray a distinctive quality and rate of evaporation.

The top note consists of an essential oil that has a low molecular weight, and therefore hits the olfactory receptors first when you inhale an aromatic blend. It also evaporates quite quickly, which causes the blend's aroma to evolve and make the other notes much more prominent.

The rate of evaporation of the middle note is not as high as the top note, but it is still faster than the base note. This middle note acts as an essential 'bridge' between the lighter and heavier oils within a blend, bringing in a sense of harmony, symphony, richness, and balance.

The base note relates to the essential oil that has the highest molecular weight, and as a result it takes much longer to evaporate. It also 'holds down' or 'fixes' the rest of the elements of the blend, making the fragrance more secure, binding, and longer-lasting.

Using the perfume note theory, we can create fragrances or blends that emanate preferred characteristics. For instance, choosing an oil from all three perfume notes (top, middle, and base) can help create a more complex, well-developed blend that enhances and unfurls over time. In contrast, choosing oils within the same perfume note can give rise to a more homogeneous blend that is uniform in its smell and performance.

Classification Based On Therapeutic Properties

Deviating away from their alluring and exotic scents, essential oils are also well-known for their therapeutic abilities. For example, essential oils such as Lavender, Ylang Ylang, and Valerian are believed to have a distinct calming quality that can soothe anxiety and induce sleep or relaxation. On the other hand, oils such as Lemon, Sweet Orange, and Peppermint are thought to be more stimulating, bringing on a more energetic and lively ambience.

For those looking to make a strictly therapeutic blend, it can be helpful to know how essential oils may be grouped according to their beneficial properties. One such framework is shown below:

This kind of grouping makes it easier to see which essential oils may be combined to produce a specific benefit that you are seeking. For example, to create a blend that promotes relaxation and eases stress, you could choose essential oils that are calming or uplifting (such as Bergamot) and avoid those that are known to be particularly stimulating or energizing (such as Ginger or Grapefruit). Similarly, to make a naturally sultry massage blend that helps enhance and arouse sensual desires, incorporating aphrodisiac oils such as Clary Sage or Sandalwood can be especially helpful.