Chemistry
⚗️ Chemistry

What Are Essential Oils?

Volatile aromatic compounds extracted from plants — and what that actually means.

Essential oils are volatile aromatic compounds naturally produced by plants and extracted through careful processing. Each word in that definition matters.

Volatile

Volatile means they evaporate readily at room temperature. This is what makes aromatic use possible — the compounds transition from liquid to gas, become airborne, and reach your olfactory system. It also means they are absorbed quickly through the skin. Volatility is not a weakness — it is what makes essential oils functional.

Aromatic

Aromatic compounds have structures that interact with smell receptors. Not all plant compounds are aromatic — essential oils are a specific subset that the plant produces in specialised structures called oil glands, glandular trichomes, or resin ducts. These structures concentrate the compounds until the plant needs to release them.

Why Plants Make Them

  • Attract pollinators

    Lavender produces linalool partly to attract bees.

  • Deter herbivores

    Peppermint produces menthol partly to deter insects.

  • Protect against environmental stress

    Frankincense produces resinous compounds as a protective barrier against injury.

  • Communicate with other plants

    Some aromatic compounds act as chemical signals between plants.

Not Actually Oily

Essential oils are not actually oily in the way vegetable oils are. They are called oils because they are immiscible with water — they do not dissolve in water and float on top of it. This is different from fatty oils (like fractionated coconut oil) which are composed of triglycerides. Essential oils are composed of volatile aromatic compounds — primarily terpenes and their oxygenated derivatives.

One drop of essential oil can contain over 100 individual chemical compounds, each in precise ratios shaped by the plant's genetics, growing conditions, and distillation method. This complexity is why whole oils behave differently than isolated compounds — and why purity matters so much.