Sultry scents of Springtime – The science of perfume

What do I wear to bed? Why, Chanel No. 5 of course’. — Marilyn Monroe. 

Chanel No. 5 is a classic perfume which is still used today, and is regarded as the world’s most famous perfume.  When Coco Chanel turned forty in 1923, she celebrated this milestone birthday by releasing Chanel No. 5.  The perfumer Coco Chanel chose to create this signature fragrance was Ernest Beaux. 

Silhouette of Coco Chanel
For her 40th birthday, the designer commissioned Ernest Beaux to create her signature fragrance – Chanel No. 5

Inspiration for Chanel No. 5

Ernest Beaux created the perfume in 1920 when he returned from his World War I experiences.  In an excerpt from his writing in 1946, ‘Memories of a perfumer’ (Souvenirs d’un parfumeur), Ernest Beaux, acknowledged his exposure ‘…to the northern part of Europe beyond the Arctic Circle at the time of the midnight sun, when the lakes and rivers release a perfume of extreme freshness’, as the inspiration for his new perfumes.  He tried to mimic these pure notes of nature using the newly developing science of aldehyde synthesis, but, at that time, the science had not yet developed sufficiently to mimic nature in all of her glory. 

Base Note, Middle Note and Top Note

According to, Chanel No. 5 has the base notes of civet, amber, vanilla, vetiver, musk, sandalwood, patchouli, and moss.  The ‘note’ of a single ingredient is its most distinguishable odour.  The base notes of a perfume are those ingredients which anchor the perfume, the scents of which, last longest on the skin.  Base notes are the least volatile ingredients in the perfume, hence their longevity. 

The middle notes of Chanel No. 5 are derived from jasmine, iris, orris root, lilly-of-the-valley, and rose.  Middle notes are derived from ingredients that have intermediate volatility, and are often described as the heart of the perfume. 

The top notes in Chanel No. 5 are ylang-ylang, bergamot, lemon, neroli, and aldehydes.  The top notes of a perfume are derived from the most volatile ingredients.  These are the notes you detect upon the immediate application of a perfume. 

Getting the balance just right

To achieve a finely balanced perfume, most perfumers, use an optimal ratio of 25 percent top notes, 20 percent middle notes and 55 percent base notes.  If a note is described as ‘aldehydic’, the description refers to a group of organic compounds which may be synthesised in an organic chemistry laboratory.  These are some of the scientific decisions involved in the creation of a perfume.  But, how do you choose a perfume when you or your loved one would like to indulge you?

How do you choose a perfume?

When you’re at the perfume counter selecting a perfume, you could spray the scent on a piece of blotter paper, or, on your clothing, or, most likely, you would spray it on the inside of your wrist.  And, if you have a friend tagging along with you, they would spray some on themselves too, if they are partial to the scent. 

When you finally get home, the scent on the blotter paper, would be different to the scent on your clothing, and different to the scent wafting off of your skin.  Even more interesting, is the point that, if your friend had sprayed the same scent on their skin, that scent drifting off, would be slightly different to the one emanating off of you, but, it should have some similarities. 

Why does it smell different on you?

Every person has a unique skin chemistry, with properties that include the pH of your skin, the oil content of your skin, and the physical attribute of how smooth or rough your skin is.  Your skin chemistry is affected by your hormones, by your diet, by the slight fluctuations you experience in body temperature, and by any emollients you apply to your skin.  It is these factors that determine the perception of how a perfume smells on you.  Perfumers call this apparent inconsistency of scents the ‘aura’ of the scent. 

Instead of skin chemistry, Mark Behnke, writing for, prefers to talk about ‘Skin Physics’.  In his piece, in which he is determined to bust the myths surrounding why perfumes smell different on different people, he talks about the moisture and oil content of a person’s skin, and how your diet will affect the overall scent of a perfume.  Apparently, it’s all about layering.  And your ‘natural “Eau de Garlic” (from your diet rich in sulfur-containing foods like cruciferous vegetables, cheeses, organ meats, chicken, to name a few), creates an additional layer of fragrance to the one you’re applying from the bottle.  Another factor contributing to your natural odour is the consumption of alcohol. 

There is yet another factor at play, and that is the colonies of protective bacteria present on our skins. 

Smell Scientist

Sissel Tolaas is a smell scientist, and she is convinced that we would be using bacteria to create perfumes in the future.  Her work is diverse and ranges from a background in Chemistry, to art and design.  One of her inventions is the Smell Memory Kit, which she developed in collaboration with the company SUPERSENSE.  In 2004, the Re_Search Lab was founded and is part of Sissel Tolaas’s studio in Berlin.  It is self-described as a ‘station of dialogues’.  The Re_Search Lab is supported by International Flavors and Fragrances (IFF), a company which creates and manufactures flavours and fragrances.  Here, an interdisciplinary approach is undertaken to understand and develop scents and fragrances, and their role in smell communication. 

There’s a lot of science going on, when you apply that perfume, and whether it is skin chemistry, skin physics, or skin microbiology, could very well be, a matter of semantics. 

But back to Chanel No. 5 – Chanel’s newest scent is called Gabrielle. Tuberose is one of its middle notes.

Gabrielle by Chanel
Described by its creators as the fragrance of an elusive flower

• This piece first appeared in The Witness on 08 October 2019.

The views and opinions expressed in this article are those of the author and do not necessarily reflect the views of Safrea or its members.

One Response

  1. Enjoyed this. I’m a huge Marilyn Monroe fan. When I started my first job as a student, the first two months salaries went towards helping with household expenses and my travel costs. However, as month three approached along with my birthday, I decided to treat myself to an “expensive” purchase that I would remember forever. It was a 100ml bottle of Chanel No. 5 cos I knew that was Marilyn’s scent of choice. Alas, it gave me a splitting headache every time I used it, regardless of how little I used and eventually went to my mom.

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