Absolute, concrete, essential oil: what's what?

Okay, nerd moment: made differently. According to the Wikipedia page on absolutes, the plant is first extracted with a solvent, hexane, which gives a concrete. The concrete is then extracted with ethanol, chilled, filtered and freed of the ethanol, and what's left is the absolute. It's stronger and slower to evaporate than an essential oil. Rant over.

So the concrete is a step on the way to the absolute. And the essential oil?

Mostly distillation. IFRA's explainer on how fragrance is made says natural materials are distilled or extracted into essential oils or concretes. Basically steam on one side, solvent on the other.

Fun fact: before solvents there was enfleurage. The article on enfleurage describes flowers laid on fat and replaced until the fat is saturated, then the scented fat washed in alcohol to give an absolute. [Jasmine and tuberose were the stars.] It's definitely mostly history now, replaced by solvent and CO2 extraction. Footnotes welcome.

Could you put a drop of the absolute on your wrist to smell it properly?

Paper strip only, Ash. An absolute is stronger than an essential oil, and what any of them does on skin is a pharmacist's question, not ours.

The methods are laid out side by side in the Class on how fragrance is extracted.

Brilliant, thanks all. Concrete, then absolute, then a strip. Project sorted.