Essential Oil Extraction Methods: How Nature’s Aromas Are Captured

Essential oils might seem like tiny vials of magic — and in a way, they are — but the method behind capturing that magic? That’s pure science, art, and a little bit of alchemy. At Delune, we’re obsessed with the details behind each drop, and we believe our community deserves to understand how these oils are born. So here’s your deep dive into the main ways essential oils are extracted from plants — and why it matters.

Steam Distillation

This is the classic — the OG. Steam is pushed through plant material at high pressure and temperature, releasing aromatic compounds. These oils vaporize, float through tubes, and eventually condense back into liquid form. What’s left is two things: the essential oil (floating on top), and the hydrosol or floral water (beneath it). Rosewater is a familiar one.

This method is ideal for: twigs, leaves, roots, and petals.

Hydro Distillation

Similar in concept to steam distillation, but here the plant material is submerged in water and then boiled. It’s slightly gentler and can yield a higher volume of oil, especially with more delicate botanicals.

Rectification (aka Fractional Distillation)

This is when oils are re-distilled to remove undesirable or even toxic compounds. It’s like giving your oil a second (or third) pass through the spa. Ylang Ylang, for example, often goes through five rounds of rectification to remove esters and isolate specific scent profiles — resulting in different grades like Ylang Extra and Grade 3.

It’s also how we get camphor oil variants like white, blue, and brown — with white camphor being the one used in aromatherapy.

Cohobation

This sounds like a medieval spell, but it’s a very real and complex process. Sometimes steam distillation can strip out key scent compounds — like phenyl ethyl from rose oil. So in cohobation, the water used in distillation is itself re-distilled and then recombined with the oil. This is how we get the exquisitely rare and potent Rose Otto.

Expression (Cold Pressing)

This is how we extract citrus oils — lemon, lime, orange, grapefruit. The oil is taken from the rind, not the juice, using a process called écuelle à piqué where tiny pinpricks are made in the peel, and it’s then pressed hard. The result? A vibrant, zingy oil rich in monoterpenes.

Interesting twist: while tangerine oil is taken from the rind, mandarin oil is steam distilled from the leaves. Nature never sticks to one rulebook.

Solvent Extraction

Some delicate flowers — jasmine, honeysuckle, hyacinth — just won’t yield their oil through distillation. So solvents like hexane (historically) or CO₂ (modern, clean, and far superior) are used. CO₂ extraction is ultra-pure and leaves behind no residue, giving us what's called an absolute.

These are the oils with the more complex and sensual aromatic profiles — think jasmine absolute or rose absolute. They're often too precious to use in large volumes, but they're powerfully effective even in small doses.

Enfleurage

Now rare, but oh-so-romantic. Petals would be laid out on trays smeared with fat, which would absorb the fragrance over time. The process would be repeated until the fat was saturated, then the fat would be washed with alcohol to pull out the essential oil. It's slow, sensual, and rarely used today — but still captures the imagination (and the scent!) of roses and jasmine from centuries past.

Why It Matters

Not all oils are created equal — and not all methods are appropriate for every plant. The extraction method affects not only the purity and potency of the oil, but also its aroma, shelf life, and potential uses. Whether steam-distilled, cold-pressed, or CO₂-extracted, every bottle we select at Delune is chosen with intention, quality, and purpose in mind.

So the next time you open a bottle of Lavender or Ylang Ylang, take a second to appreciate the journey it’s been on — from field, to flower, to flask.