Science in a bottle. Essential oil extraction methods

Essential Oil Rosemary and Lavender

Have you ever wondered how to extract essential oils from plants? Essential oils are liquids or the “life force” or the beneficial liquefied version of a plant that reach the bloodstream faster than it would have been by consuming the plant.

The extract of plants is produced when the material is in contact with a solvent in which part of the plant material dissolves and the result is in a liquid form. The solvents are agents that help plant cells to break down and release their contents.

The different extraction methods are:

Solvent extraction like hexane and ethanol to isolate essential oils from plant material. Solvent Extraction encompasses the following methods: Hypercritical CO2 (Carbon Dioxide), Maceration, Enfleurage (fat).

Maceration:  The process when carrier oils are used as solvents to extract therapeutic properties from plant material.  Plant material is finely cut or ground into a coarse powder and closed into a vessel where in the solvent is added.  The mixture is allowed to stand for 1 week and it is shaken occasionally from where the liquid is strained.  Solid residue (marc) is then pressed to recover remaining liquid and then the strained and expressed liquids are mixed and clarified through filtration.  A macerated oil does not have a long shelve life.

Cold press extraction (citrus peel in particular):  The whole fruit is placed in a device that mechanically pierces it to rupture the oil sacks under the rind.  The pressed essential oil and pigments run down into the device’s collection area where the whole fruit is pressed to squeeze out the juice and oil.  The content must be centrifuged to separate the solids from the liquids which is siphoned off into another receptacle.

Steam distillation:  During the steam distillation process, steam passes through the plant material. Plant material goes into a stainless-steel container and steam is injected onto it.  The combination of heated steam and gentle pressure causes the essential oil to be released from microscopic protective sacs.  It causes the plant to release its aromatic molecules and turning it into vapor.  The vaporized plant compounds travel to the condenser where two separate pipes make it possible for hot water to exit and cold water to enter.  This makes the vapor cool back into liquid.  The aromatic liquid by-product drops from the condenser into a separator container.  Because water and oil does not mix the essential oil floats on top of the water where it is siphoned off from the hydrosol (floral water) and collected.

Some extraction methods are best suited for certain types of plants.  At Lamara steam distillation is the best extraction method for our Lavender and Rosemary plants.

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.