Fragrance 101: Olfactive Pyramid
What are top, heart and base notes?
Perfume can seem intangible. Though the link between smell and memory has long been established, the visceral — often emotional — process of perceiving scent can override our ability to quantify it. Frankly, it’s hard to make sense of what’s going on.
It’s important to think about perfume as a composition that develops over time: from the moment the liquid touches the skin, a chemical and biological interaction is at play.
During the late 19th century, perfumers formed a consensus around how best to recognise the olfactory stages of a fragrance. In so, the olfactive pyramid was born, and with it, the idea of perfume being linear — or flat — was yesterday’s news, giving rise to a new reality that fragrance changes over time and should therefore be considered as three-dimensional.
The Olfactive Pyramid helps us to understand all this. Its three component parts — top, heart and base — allow us to arrange notes and ingredients according to their olfactory characteristics, and, in turn, indicate how they evolve on the skin.
Top notes are the initial impression upon application. They tend to be vivid and vibrant, an all-action curtain-raiser to grab our attention. These notes are typically fresh, assertive and sharp, with citrus fruits (lemon, lime, orange, bergamot, grapefruit) and ginger the most commonly used. Molecules of this note class are small, light and volatile, and evaporate quickly. Their fleeting nature means you’ll rarely detect them after 30 minutes on the skin.
Heart notes are the soul of a fragrance and characterises its true personality. Unlike their top note counterparts, they are typically well-rounded and mellow, emerging shortly before the top notes dissipate, transitioning into the base notes. Flowers, spices, vegetal notes and fruits are commonly used in this note class and have an average lifespan of up to 4 hours.
The base notes are the foundation of a perfume, the platform from which a fragrance is built. These notes add depth and typically consist of resinoids, rich woods, sweet spices such as vanilla, animalic notes and musk. They often act as fixatives which help to hold and boost the strength of the lighter top and heart notes. Molecules in this note class are large and heavy and are detectable for 6+ hours.