Essential Oil & Hydrosol Production – Steam Distilling Lavender
FAMILY: Labiatae (Lamiaceae) (Mint)
The broad botanical genus Lavandula is home to Lavender. As of Aug 2008 there are 39 species of lavender of which Angustifolia (English or True Lavender) and Lavandula x. Intermedia (Lavandin) are the top oil producers. Angustifolia is more highly prized than the oil from the Lavandins but the Lavandins produce a higher yield. Most of the oil you will find will be from the Lavandins.
The difference between these two species is found in the oil content. The camphor content in oil made from the Angustifolia’s is between 0% and 0.6%. In the Lavandin oil it is between 6% to 8% which is why Lavandin is not used as a culinary lavender.
That said the top varieties of Lavender for it’s essential oil are the Lavandins. Lavandins are a cross between L. Angustifolia and L. Latifolia. They tend to be robust and can grow rather large. It is easy to propagate this variety and they can have up to ten times the oil content as the Angustifolia’s. The most common types of Lavandin are:
The distillation process consists of passing heated water/steam through lavender cuttings and then condense the water/steam separating the oil from the water. The oil is lighter than the water so it floats to the top. The water is the hydrosol and the oil is the essential oil. The oil is drawn off and both are bottled.
Steam injected into the container with the lavender has the highest rate of extraction. The second best method is where water is boiled underneath the lavender bin creating steam which then passes through the lavender and then condensed. This is the second best way to distill essential oil. The third and least productive is where the lavender is placed into boiling water and then condensed.