Visualizing a fragrance: what is the olfactory pyramid?
Choosing a personal fragrance is never an easy task: olfactory compositions, especially those created in artistic perfumery, are a succession of multiple raw materials that are skillfully blended by the perfumer to create a scent whose notes will evolve and change over time: when first sprayed, we perceive the top notes, then the heart notes emerge, and finally, after many hours, only the base notes remain — the most long-lasting ones.
To better understand this layering, we refer to the olfactory pyramid, a method that helps us visualize the structure of a perfume by considering the volatility and persistence of its components. The raw materials used in an olfactory composition have different molecular weights, which make them more or less diffusive and perceptible at different times. For this reason, we speak of top notes, heart notes, and base notes.
Top Notes
These are the lightest and most volatile elements: they are perceived immediately and give the first impression of the perfume. At this stage, we often find citrus fruits, aromatic herbs, and fresh spices such as bergamot, mint, or pink pepper. They are bright and sparkling notes, but they tend to fade quickly.
These notes bring freshness to the composition and help the essence “lift” from the skin, but they are also the least persistent.
Heart Notes
The heart notes are composed of medium-weight raw materials such as flowers, spices, and lighter woods: fairly diffusive and persistent, they form the core of the composition and often define its olfactory family.
Base Notes
Finally, we have the heaviest and densest materials — such as woods, resins, leather, or tobacco — which make up the base notes of a composition, performing a fixing action: less diffusive but highly persistent, these raw materials slow down the evaporation of a fragrance, “fixing” it to the skin and giving it lasting power.
It is important to note that the olfactory pyramid applies only to alcohol-based perfumes: in oil-based compositions, evaporation occurs much more slowly, so the various essences are perceived in a more linear and uniform way, as oil naturally adheres to the skin and remains anchored to it for longer.
A different principle applies to home fragrances: in this case, the olfactory pyramid does not apply, since the main goal in creating a room scent is to design an essence that releases a single, constant aroma. Therefore, only a few ingredients — usually two or three olfactory notes — are used to ensure linearity and consistency throughout the composition.