The Scent Story – Part 2
How are Essential Oils extracted?
Essential Oils are the naturally recurring oils found in all plant species from giant Redwoods to the tiniest rose bush. There are two key methods for extracting them: Distillation and Expression.
Distillation has been practiced throughout history to extract essential oils from plants using evaporation and condensation to separate the naturally recurring oils from the plant’s water system. Essential oils, or aromatic oils as they were once known, have been used by many cultures around the world for centuries. Their uses varied between cultures from religious purposes to healing the sick. It is difficult to pinpoint exactly when essential oils became known as an effective healing agent, but eventually the knowledge of essential oils spread around the world. There is evidence in French cave paintings as far back as 18,000 BC suggesting the healing & medicinal purposes of plants.
This is the most common method of extracting essential oils. The advantage of steam distillation is that the volatile components can be distilled at temperatures lower than the boiling points of their individual constituents and are easily separated from the condensed water.
The plant is placed on a grill inside the still, then sealed. The plant is then broken down with the addition of pressurised steam to the chamber. The components then rise with the steam through the connecting pipes to the condenser which quickly brings them back to liquid form. This liquid is then collected. Since water and oil do not mix, the essential oil can be siphoned off the top of the water. Occasionally, but rarely, the essential oil can be heavier than the water and can therefore be siphoned off the bottom rather than the top.
Expression (or Cold Pressing)
This method of extraction tends to be specific to citrus essential oils such as tangerine, lemon, bergamot, sweet orange and lime. Historically the rind of the fruit would be expressed via hands on sponge pressing. The rind or zest would be soaked in warm water to ready the cells, then a sponge would be used to press the rind thus breaking the oil cavities and enabling extraction. The sponge would absorb the oil which could then be harvested in a container. As with distillation the essential oil could then be siphoned off the citrus liquid once settled.
These days Cold Pressing is much less labour intensive! The rind or zest of the fruit is now prodded and pricked in a specific machine, designed to target the essential oil cavities to release the oil. The water and oil solution that is released is then collected below enabling the oil to be siphoned off later on.
So which do you think is best?!
At TJK we use essential oils that have been cold pressed thus ensuring our oils haven’t been tampered with via heat or steam. We would never use Solvent extraction nor Carbon Dioxide extraction as this can add dangerous elements to the extraction process thus effecting the final product.