Extracting scent from natural botanicals requires isolating delicate volatile compounds without destroying their olfactory profile.
1. Steam Distillation
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The Process: Plant matter (leaves, woods, hearty petals) is placed in a still over boiling water. As pressurized steam rises, it ruptures the plant's microscopic oil glands, vaporizing the volatile aromatic compounds. The steam and vapor travel through a cooling coil (condenser), condensing back into liquid.
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The Output: Essential Oil (floats on top and is skimmed off) and Hydrosol / Floral Water (the aromatic water beneath).
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Best For: Resilient botanicals like lavender, patchouli, sandalwood, cedarwood, and rose.
2. Solvent Extraction
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The Process: Fragile raw materials that degrade under high heat are washed with volatile chemical solvents (traditionally hexane, petroleum ether, or ethanol). The solvent dissolves the plant's waxes, pigments, and fragrant oils. Once the solvent evaporates at a low temperature, a waxy paste remains.
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The Transformation:
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Step 1 (Concrete): The thick, wax-rich paste containing essential oils and plant waxes.
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Step 2 (Absolute): The concrete is washed with pure ethyl alcohol and chilled to freeze out the insoluble waxes. Once filtered and the alcohol is distilled off, a highly concentrated liquid called an Absolute remains.
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Best For: Heat-sensitive, fragile blossoms such as jasmine, tuberose, orange blossom, and narcissus.
3. Enfleurage (Cold & Hot)
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The Process: An ancient, labor-intensive artisanal technique developed in Grasse. Odorless purified animal or vegetable fat is spread onto wooden-framed glass plates called châssis. Freshly picked flower petals are pressed face-down into the fat, which absorbs their scent molecules over 24–72 hours. Petals are painstakingly removed and replaced with fresh harvests until the fat is fully saturated.
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The Output: The saturated fat (pomade) is washed with alcohol to extract the fragrance, yielding enfleurage absolute.
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Current Status: Mostly historic due to immense labor costs, though celebrated by niche and heritage perfumers for preserving the exact "living flower" aroma.
4. Supercritical $\text{CO}_2$ Extraction (Modern Standard)
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The Process: Carbon dioxide is brought to a "supercritical" state—pressurized and heated until it behaves like both a gas and a liquid. It penetrates botanicals deeply like a gas while dissolving scent compounds like a liquid solvent. Returning the system to standard atmospheric pressure turns the $\text{CO}_2$ back into a harmless gas that evaporates completely.
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Best For: Spices (pink pepper, ginger, vanilla) and delicate flowers, yielding an exceptionally true-to-nature, solvent-free extract.