In Lesson 3, we turn our focus to the fascinating journey that essential oils take from plant to bottle. Essential oils are the concentrated essence of plants, and capturing their delicate aromatic compounds requires skill, precision, and a deep respect for the natural world. The method by which an essential oil is extracted plays a crucial role in determining not only its fragrance but also its therapeutic value and purity.
In this lesson, you’ll gain insight into how essential oils are carefully obtained using four primary extraction methods. Each method is chosen based on the type of plant material being used and the nature of the oil it produces. From ancient techniques like steam distillation to innovative processes like CO₂ extraction, understanding how these methods work will enhance your ability to select oils that best suit your intentions, whether for personal care, home use, or wellness applications.
Essential Oil Extraction
Steam distillation
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The most common and traditional method, steam distillation involves passing steam through plant material, which causes the essential oil glands of the plant parts to release their volatile compounds. We capture these vapors and send them through a separate cooling container where they condense back into a liquid form. The essential oil naturally separates from the water and is then collected. The leftover water from the steam is called a hydrosol, like rose or lavender hydrosol, which is also sold for many uses.
This method is ideal for plants with structures like leaves, stems, bark, and certain flowers. Most Aura Cacia essential oils, such as Lavender, Peppermint, Eucalyptus, and Tea Tree, are steam distilled.
Solvent extraction
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Used for delicate plants or those yielding minimal oil, solvent extraction involves soaking plant material in a solvent that draws out aromatic compounds. The solvent is later removed, leaving behind an “absolute”—a richly aromatic oil, ideal for perfumery. Jasmine and Rose absolutes are examples. This method preserves delicate floral notes and requires less plant material than distillation.
Expression (Cold Pressing)
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Common for citrus oils, expression mechanically presses the peels to extract oil without heat or chemicals, maintaining a fresh, vibrant aroma. It’s a sustainable method, as it often uses rind byproducts from the juicing industry. Oils like Lemon, Sweet Orange, and Bergamot are cold pressed and are popular for their uplifting scent in diffusers, body care, and cleaning blends.
CO2
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A modern method using pressurized carbon dioxide to extract oils without heat or solvents, preserving more plant constituents. CO₂ acts like a solvent under specific conditions but leaves no residue. It’s ideal for sensitive or resinous materials. Aura Cacia uses this for select oils like Turmeric and Vanilla, where a gentle, thorough extraction is needed.
