About Lavender Oil
I get asked so much about lavender and lavender oil that I started putting together some information - and ended up with an essay!
Lavender Oil Producing Plants
“Lavender” is part of the broad botanical genus - Lavandula. This is thought to be made up of 50 different species.
For the purposes of lavender oil we are mainly concerned with two species – lavandula angustifolia (sometimes called English lavender or true lavender), and lavandula x intermedia (Lavandin).
An oil is also produced from lavandula latifolia (Spike or Spanish lavender), but not at Jersey Lavender. Other species such as lavandula stoechas (French lavender, butterfly lavender) or Lavandula dentata (Toothed lavender) might also be used to produce an oil in small quantities somewhere in the world.
Within each of the species there are many varieties. Lavender farmers around the world will argue about which ones produce the best oil. At Jersey Lavender we grow five varieties of angustifolia and one of lavandin.
Although the oil of lavandula angustifolia (I’ll refer to this as just "lavender" from now on) is more highly prized and expensive than that of lavandin, in fact far more of the lavandin oil is produced in the world. The main reason is because lavendin has a much higher oil yield and flowers profusely so that, even with lower prices, farmers make more money per field area. The other reason is that the demand for lavandin oil is much greater as it is used commercially in cheaper, high volume fragrances (laundry detergents, soaps etc.) Lavender oil, on the other hand, is used in higher-priced, lower volume fragrances for products such as perfumes, cosmetics, skin creams and top quality bath products - including our own!
The Difference Between Lavender and Lavandin Oils
If you compare the smell of lavender and lavandin the difference is very noticeable. Most of the different chemicals (up to 120 of them) are pretty similar, however, one key difference is a chemical called Camphor. Camphor has a harsh, sharp, strongly pungent fragrance (almost reminiscent of a cold remedy!). In lavender the camphor should be between zero and 0.6%; in lavandin it is between 6% and 8%.
Within each species of lavender there are many different varieties. So it is no surprise that the oils derived from each of these varieties are different. Which oil is “best” is largely a matter of personal opinion, but each particular variety does seem to produce consistent patterns of different chemical components which lead to a consistency in their odour and therefore make them distinguishable from other varieties.
Added to the oil differences that the species and varieties produce, there are other variables such as soil type, nutrition, water, sunlight, temperature, age of plant, time of harvesting in the flowering season etc. – all of which affect the oil, some to a greater extent than others.
Where in the World?
Most lavender species used for oil production are indigenous to the Mediterranean region. Provence in the south of France is the “home” of lavender oil production, but now it is grown (and the oil extracted) in many areas further afield. The are bigger farms producing oil for the commodity essential oil markets in Bulgaria, Ukraine, Yugoslavia, Czech Republic, southern Russia, Australia, and China. Smaller farms such as Jersey Lavender are found, with new ones starting up all the time, in the UK, Australia, New Zealand, Canada, USA, South Africa and South America.
The lavender is closely monitored and around the middle of June we judge our earliest -flowering variety of angustifolia (called “No.9”) to be at its optimum level and the harvest begins.
Harvesting is done by laying fine-mesh nets either side of the row of lavender and cutting the flower stems off with powered hedge trimmers. The lavender falls neatly onto the nets, which, once full can be bundled up and put into a trailer. In larger commercial enterprises harvesting is carried out with a tractor-mounted or specialist mechanical harvesters.
From the fields the lavender is taken to our distillery, where it is loaded into steam stills. The harvesting of the angustifolia species of lavender is usually completed by the end of July and then we move onto the later flowering lavandin, until that is complete towards the end of August.
The Distillation Process
All our lavender oil is distilled from plants grown on the farm in Jersey. The process is a fairly straightforward one and in many respects hasn’t changed for many centuries.
At the peak of our lavender harvest we usually do 4 or 5 distillations each day in our two stills. Our biggest still takes about 85kg of fresh weight lavender, and it takes about an hour and a half to distil the oil.
The lavender is packed into a steel mesh basket, weighed and winched into the stainless steel still. A lid is put on and bolted down. Steam is then introduced under pressure into the bottom of the still from our oil-fired boiler. The steam at 100°C rapidly rises into the lavender, heating it up.
All the different chemical components that make up the lavender oil (which is stored in tiny vesicles along the sides of each flower bud) have a boiling point less than the temperature of the steam. When subjected to the steam the lavender oil chemical components boil - turn to a vapour and rise with the steam to the top of the still.
The steam and oil vapours pass through a short pipe to a water-cooled condenser. Here it is cooled back to water and minute lavender oil droplets, and this mixture flows into a special glass flask. The flask allows the liquid to settle and separate out into a water layer and a lavender oil layer – the lavender oil is lighter than water and being an oil does not mix with water so it floats on the top as a beautiful, golden coloured layer. From the flask the oil is drawn off and stored away carefully.
Storage and Maturing
If plant oils are not stored correctly the oils can deteriorate quite fast through various chemical reactions. The principal enemies are water and oxygen in the presence of excess heat and light. Our essential oil is first dried using a special drying agent (a powder that is mixed in that absorbs moisture), and then filtered and weighed into large glass bottles. The bottles are filled to the top to minimize the air pocket (with oxygen in the air), and the lid tightly sealed on which stops both air getting in and the oil evaporating. To further minimize any damaging reactions, the containers we use are made from darkened glass, and once filled they are stored in a cool cupboard.
Initially, after distillation the lavender oil has a “rough” odour to it – some people have described it as an intense, sharp hay smell – and it isn’t very pleasant. The oil, once stored away goes through a maturing process which takes about six months. After six months we continue to leave the oil stored away safely until we need it, which is generally between one and two years after distillation.
The angustifolia seems to produce a yield of about 0.4% to 0.7% by weight. The actual yield depends on the va