The Olfactive Pyramid

3 minute read by Fiona Cooke, in 725 words.

Source – RGB Images
The Olfactive Pyramid
What have pyramids got to do with perfume?  The olfactive pyramid is just a simple way to try to explain how perfume is (sometimes) constructed and how it behaves on your skin.

Let’s say you have all these ingredients or aromatic essences, well some of them float away very quickly so that you only smell them for a short time, while others stay around a lot longer. Ever smell your perfume on your scarf the next day? Smells totally different from the first spray? That’s because only the ‘base’ notes remain.

Perfumes are generally made up of TOP notes, HEART notes and BASE notes.

All this simply means is that each ingredient is a chemical molecule, and each of these molecules has a weight. Some ingredients are really light and float away quickly, whilst some molecules are heavy, and stay around on your skin longer.

‘Top notes’ are the ones that evaporate and fade away quickly.

A lot of citrus or aromatic notes are mostly top notes. They are there to give the perfume its initial kick and usually the first part that you would smell.

The ‘heart notes’ are mainly the body of the whole perfume – how the perfume is generally supposed to be remembered – the soul of it.

The notes in here are heavier and last a long time (a few hours). The ingredients that are used in this bit determine how we will categorize the perfume and call it a ‘FAMILY’. We’ll be talking about families in a separate post.

Source – RGB Images
The base notes are the really heavy ingredients that stick around on the skin long after the party is over. They are often called fixatives as they help fix the perfume to the skin.

In traditional perfume (before we intervened with science to stop the whole thing being a bit cruel) these were usually natural animalic notes. Think about it. When animals mark territory with their scent, it is supposed to stay there on that piece of territory for a very long time, so that other animals can read the scent messages. So it’s not surprising that when we start using these scent sacs in perfume, they are the ones that hang about for ages – that’s their whole point! So we can kinda tell which ones are fleeting and which ones aren’t – generally you can sense that most citrus notes don’t hang about, and a lot of musky ones do.

But even better than that; in the 1920s a Yardley chemist called Poucher decided to rank ingredients from 1 to 100 so we can tell which are the most volatile notes and will float away or evaporate quickly. When we want to describe how a traditional perfume should behave, we talk about the ‘olfactive pyramid’, which just indicates the strength, and how long the ingredients last.

(Poucher was also known for his widely acclaimed mountaineering guidebooks and photography, and in 2012 was the subject of BBC Radio 4’s The Perfumed Mountaineer.)

Pyramid 2
Graph sample – Olfactive Pyramid

NOW, just to add complexity to the whole thing, this ‘pyramid’ was only meant to loosely talk about heavier molecules all the way up to lighter molecules and how they evaporate on the skin. But since then, with more advances in technology and chemistry, we are able to create very stable formulas that remain the same from start to finish. They are called ‘linear’ fragrances and became most popular in the 80s.

Lancôme’s Trésôr and Estée Lauder White Linen were among the first ‘linear fragrances’.

Now that aromas are made with more scientific processes, or with better extraction methods used, you can get very exact and precise aromatic essences that will smell the same from start to finish. The whole concept is a bit redundant, but we have adapted the pyramid into “perfume-speak”, so people still tend to use it.  

So next time you see this pyramid, you shouldn’t be wary.  It’s just a visual graphic from the perfume makers to you to explain how the perfume is put together.

Our aim is to help you understand perfume in a jargon-free way.  If this is the kind of stuff that interests you, then sign up for our mailing list – we are writing new stuff about this all the time.

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