Lavender Oils; What and Why?
Lavender Oil comes in two main forms. Lavender oil which is made from cultivars of the species Lavandula angustifolia and Lavandin Oil which comes from cultivars of Lavandula x intermedia. L. angustifolia is a small shrub that naturely comes from above 1000m in southern France. L. x intermedia is a larger hybrid of Lavandula angustifolia x Lavandula latifolia. It occurs naturely between 600 and 1200 m.
There are also oils made from Lavandula latifolia and palnts from the group Lavandula x heterophylla and Lavandula x allardii. All of these are high in camphor and Borneol and are not suitable for culinary or perfumary uses.
Real lavender or lavandin oils are expensive. Good quality, pure oil from Lavandula angustifolia is the dearest and can range from around $100 to $700 per kg depending on the origin and quality. Lavandin oil generally sells for $25 to $100 per kg. Both oils are clear to pale yellow with a characteristic fragrance that is sweet with floral overtones. Lavandin is a bit shaper due to the higher concentrations of the various constituents.
The quality is usually assessed by the ‘nose’, much the same way wine is assessed by its nose, color and taste. There are five main components that are of concern. These are Cineole, Linalool, Camphor, Borneol and Linalyl acetate. The breakdown of these components is governed by the genetic make up (ie the variety) and the local environmental conditions (ie weather, soil nutrient and surrounding plants). The Lavender oils have lower rates of Camphor, (technically less than 5% but really need to be below 1.5%) Borneol and Cineole. Lavender oils come from cultivars of Lavandula angustifolia that have been selected for their oil content. In some cases this selection has occurred over several hundred years.
The better producers generally have their own selected cultivars. Some producers may use three or four cultivars that are then blended in specific measures. There is still a demand for a product the French call Lavender Sauvage or Wild Lavender. This oil is made form either wild collected flowers or from plants that come from wild collected seed. In selecting cultivars it is both the quality and the quantity that is looked at. The better forms have oil that fits the international standard for the percentages of the constituent oils, that have a good ‘nose’ and are high yielding.
Lavandin oils have higher rates of Camphor, (between 6% and 16%) Borneol and Cineole. Lavandin oils come from varieties of the hybrid Lavandula x intermedia. The selection is very limited as it is a naturally occurring hybrid that is sterile so there are very few seedlings to select from. Lavandin plants generally yield three to four times as much oil as Lavender which is why it is less expensive.
This is an overview, a full analysis reveals in excess of sixty component oils. It is the ratios of these component oils and the way the blend that gives the oil its characteristic ‘flavours’ An oil may or may not meet the standard but still be a high quality perfumery or aromatherapy oil. Then other oils are considered as low quality by the experts but are liked by the consumer. However adulterated oils are generally seen as inferior and can be picked when compared closely with pure or true oils.
If you are buying oil you can take it that cheap prices indicate poor quality, synthetic or adulterated oils. Good lavender oil has numerous medicinal and therapeutic properties that are lost with adulteration. When buying look for oils that are locally made and have the name of the producer and the cultivar on the bottle. It is a sign of a maturing industry that many good producers keep the oils from the different cultivars separate and sell them under their cultivar name.