How Are Essential Oils Extracted From The Plant?
Essential oils are highly concentrated aromatic extracts that are distilled or expressed from a variety of aromatic plant material, including flowers, flowering tops, fruits/zests, grasses, leaves, needles and twigs, resins, roots, seeds, barks and woods.
Other processes such as enfleurage and solvent extraction produce aromatic products called “absolutes.” Enfleurage is a process that uses solid odorless fats at room temperature to capture the fragrant compounds exuded by plants. The temperature can also be increased or decreased to then utilize the “hot” or “cold” enfleurage methods. Solvent extraction is a technique for removing a desired component from ores by transferring the component from an aqueous to organic solvent that can then be separated. Another process called CO2 extraction produces a very clean, quality oil with little-to-none post processing.
Distillation appears to have been practiced throughout ancient times, with known production, or extraction, of essential oils dating back to 3,000 BC. Today, distillation is still the most common process of extracting essential oils from plants! The advantage of this method 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.
Both essential oils, and hydrosols which we’ll explore later in this article, form a molecular marriage. When we pick up an essential oil, we could say that we are holding a physical manifestation of alchemy!
The Distillation Process...
During distillation the plant material is placed upon a grid inside the still. Once inside, the still is sealed, and depending upon the exact distiller, steam or water/steam slowly breaks through the plant material to remove its volatile constituents.
Note that the PH and type of water used are definitely factors in this process, and the PH of the water should be checked before plant material is added and then continually throughout the process.
These volatile constituents rise upward through a connecting pipe that leads them to a condenser. The condenser cools the rising vapor back into liquid form and the liquid is then collected in a container below the condenser. Since water and essential oil do not mix, the essential oil will be found on the surface of the water where it is then, or can be, siphoned off. Occasionally an essential oil, such as Clove, is more dense than water and will be found sunk at the bottom instead of floating on the surface. In this case, the water can be removed and then the oil can be siphoned from the bottom instead. If a smaller distiller is being used, the collection bottles will be blended together into one so they harmonize and equalize. And then you have the essential oil of a plant gathered!
Check out the vintage video at the bottom of the page on Lavender harvest and distillation! Today, the process remains almost unchanged after all these years.
If you want to watch an hour-long in-depth presentational video on distillation, follow the linked article presented by The School for Aromatic Studies: https://aromaticstudies.com/distilling-with-cathy-skipper/
So what are hydrosols?
Hydrosols, also known as hydrolats (meaning “water milk” in French), are a byproduct of the distillation process and at times, even the main product! Hydrosols contain the water-soluble constituents of the plant and retain a trace amount of the essential oil - but don’t think of them as “diluted” or “impotent” in any way. While the lipophilic non-polar molecules are repelled by water and you won’t find them, you will find the alcohols and some acids! Typically used as sprays and facial toners, hydrosols have a wide range of cosmetic, medicinal and even culinary applications.
You can generally use any part of the plant in making hydrosols and there are three different varieties of such: the aromatic, slightly aromatic (Meadowsweet and Yarrow for example) and then the non-aromatic hydrosols. When thinking of what part of the plant does what, let your intuition guide you. We are, after all, connected to the same Source and the plants will and are talking to you, if you listen. Ask them. Roots of plants, for example, are typically very warm, stimulating, and make great tonics because of this. In comparison to how they gather nutrients from within (the Earth) and bring it up, rising in the process, root medicine for us too, will do the same - grabbing toxins and bringing blood to the surface of our skin. Harvest roots in late spring to summer depending, when plants are chock full of vitamins and minerals and are waking up from their winter slumber. Leaves are typically more cooling. Barks of trees like Birch and Willow are wonderful. Be careful of your and the surrounding energies not only when you harvest but distill, as it affects the hydrosol’s overall energy and potency on a spiritual and molecular level.
Interestingly, by 1708 there were already 120 hydrosols commonly used in France. By the 18th century, there were 200 and many of them were codexed. But by the mid-19th century, the codexed products dwindled and by 1965, there were none. There, at least from a pharmacological standpoint, they have remained. However, like essential oils, they seem to be making a strong comeback!
How and with whom to use hydrosols:
Hydrosols are probably the best way to get to know a plant’s energy, and healing properties. They are also much easier to work with as you can utilize any part of the plant and are therefore more forgiving teachers. On a more practical level, hydrosols are great in the herbalist’s toolbox as they don’t have any safety issues.
Great and perhaps the best method of oral consumption, hydrosols are even gentle enough for small children, sensitive people, and those with allergies. In fact, it’s so gentle you can use them in your eyes as compresses or baths.. and Cornflower and Chamomile are my favorite plants for this use.
They can also be used long-term for chronic symptoms with no worry in negatively affecting the body, or working against other medicines.
As mentioned above, hydrosols are most commonly used as toners and astringents, but have a wide variety of antimicrobial and antibacterial uses in both cosmetic and medicinal application. Some of my favorite ways to use them are in creams, foot baths, and in cooking!
Because they’re so light, potent, and contain alcohol, they’re especially wonderful in healing wounds due to their noteworthy draining action.
Create sprays or a add to tonic. Whether for its antibacterial properties or aroma, hydrosol sprays are also absolutely wonderful, and very skilled, in working with energies. They tend to have a very high resonance effect, and not only will form a protective field around you or whatever is sprayed, but will lift energies higher.
Generally cooling, calming and refreshing. Hydrosols are great for burns!
Hydrosols can be layered easily and are a beautiful addition in creating a wholesome wellbeing medicinal product..
Ultimately.. play with them, wear them, get to know them. Listen to yourself and your body’s reactions!
Please note that the addition of essential oils to water is not at all the same as true hydrosols, and make sure that you read the ingredients label on purchased products to ascertain whether or not you are getting a true hydrosol. When water and essential oils are mixed together with or without a dispersant, this is called a “spritzer” or an “aromatic spritzer.”
As a general rule, people say 1 kilo of plant material will give you one liter of hydrosol but the mediums’ volumes aren’t the same so this is not a good indication.
Expression, also referred to as cold pressing, is the second method of extracting an essential oil from the plant material, and is specific to citrus oils such as Tangerine, Lemon, Bergamot, Sweet orange and Lime. In older times, the process of expression was done in the form of sponge pressing, which was literally accomplished by hand. The zest or rind of the citrus would first be soaked in warm water to make the rind more receptive to the pressing process, and a sponge would then be used to press the rind, thus breaking the essential oil cavities and capturing the oils through absorption. Once the sponge was filled with the extraction, it would then be hand-pressed over a collecting container and would conclusively be left to stand to allow for the separation of the essential oil from the water/juice. Just like in distillation, the essential oil would then be siphoned off and you’d have your finished product!
A more modern and less labor-intensive method of extraction has been coined the “écuelle à piquer” process - and involves a prodding, pricking, and sticking action. During this process, the rind of the fruit is placed in a container having spikes that will puncture the peel while the device is rotated. The puncturing of the rind will release the essential oil that is then collected in a small area below the container. The end process is the same. Furthermore, the majority of modern expression techniques are accomplished by using centrifugal machines. The spinning in a centrifuge separates the majority of the essential oil from the fruit juice, thereby creating less waste and a more potent product!