Harvesting of Essential Oils

During harvesting the various raw materials such as bark and flowers which have different properties require different handling processes. Experienced oil producers and distillers understand the nuances and have perfected this art form.

Following a harvest of plant material large containers are loaded and steam is gently and skillfully circulated under pressure. The steam rises up through the plant material and the natural aromatic compounds are naturally liberated with the steam. As the steam cools the water and oils naturally separate and the oils are collected in their pure form.

Essential Oils

To ensure the highest quality oil with the correct chemical composition for that plant for example (lavender) temperature and pressure must be monitored very carefully and standardized for each type of raw material. Too little heat and too little pressure will not release the valuable oil, while too much heat or pressure can change an extracts composition and potency.

The essential oil that is left behind is collected in a holding tank leaving behind the NON aromatic compounds. This does not mean that the non-aromatic compounds are not useful however they are not part of the newly distilled therapeutic grade essential oil.
For optimal extraction it is critical to control the rate at which temperature increases and decreases and also the amount of pressure applied to the plant material.

If these processes are not observed and steam is circulated too fast too hot or for too long a lot of the other compounds become mixed into the distillation process.
This is a cheaper easier less detailed methodology adopted by many companies – they may look like essential oils claim to have therapeutic benefits but allow them to maximize profits.

Cold pressing of essential oils is the preferred method for obtaining the Citrus oils, such as lemon, lime, tangerine, bergamot and orange. This method of obtaining citrus oil is called Cold pressing as no heat source is required. Citrus essential oils are found in the rinds of their fruit.

Fruit is placed in expression machinery where it is passed across rasping cylinders like a giant cheese grater. The grating action causes the small sacs of essential oil to break open and release their contents. Water is sprayed over the fruit and the essential oil is collected in a watery mix. This watery mix contains materials from the fruits flesh, and some solid particles from the rind. To isolate the essential oil the mixture is filtered and centrifuged allowing separation of pure essential oil product from any water or solid particles.

Essential Oils
Modern day aromatherapy adopts three methods of use.
  • Aromatically
  • Topically
  • Internally(therapeutic grade only!)


Aromatically essential oils are detected via the process of Olfaction. The process of olfaction occurs when an odor molecule is inhaled into the nasal cavity it is first sensed by the OLFACTORY cells that are part of the OLFACTORY EPITHELIUM. The olfactory epithelium is made up of two small patches of olfactory nerves that are found on the roof of the nasal cavity.

Essential Oils

The olfactory cells within the olfactory epithelium are specialized nerve cells that extend cilia from their dendrites into the nasal cavity. Each of these cilia house receptors that bind to a specific type of odor molecule. When an odor molecule binds to a receptor on the cilia of an olfactory cell the olfactory cell passes the signal through the cribriform plate (the bone at the roof of the nasal cavity) to the olfactory bulb.

The olfactory bulb in turn sends those impulses along the lateral olfactory tract to five different structures in the brain including the amygdala (which is responsible for storing and releasing emotional trauma).

Anatomically the olfactory system is closely connected to the limbic system of the brain. The limbic system includes structures such as the hippocampus (long term memory) the amygdala (emotions) the hypothalamus (autonomic nervous system and hormones) and the cingulate gyrus (regulates blood pressure and heart rate and attention). Due to the fact that the olfactory system is so closely connected to the limbic system of the brain essential oils have such profound physiological and psychological effects.


Essential oils have an affinity with sebum (oils from the sebaceous glands) found adjacent to our hair follicles. It is primarily through this route and the enlarged pores on the soles of the feet that allow the uptake of essential oil to enter the bloodstream. This can occur within a matter of seconds following application of an essential oil directly to the skin.

Essential oils used topically have very powerful therapeutic benefits. From relaxation to detoxification essential oils can be applied topically at home or incorporated into a treatment regimen. Skin care treatments, massage therapy and body therapies can all utilize the therapeutic benefits of essential oils. Used to customize treatments for personalized results or to target specific individual or client needs they should be a staple both in the treatment room and at home.


The internal use of therapeutic grade essential oils is not a new concept however it is making a comeback and while common practice in some European countries is relatively new to the USA. Great care to the quality and efficacy of essential oils is particularly important if used in this way. Not all essential oils are beneficial if taken internally so it is important to ensure the particular oils you are using are certified GRAS (generally safe for human consumption). It is also important to pay attention to the quantity of essential oil being ingested.

Just because an essential oil can be taken internally doesn’t necessarily mean that is the best way to take it, depends on the person and the result you hope to achieve.

Continue reading to learn about chemical constituents of essential oils.