What does a synthetic molecule smell like?

Ethyl-maltol, aldehyde, calone... Much less evocative than rose or tuberose, they nevertheless have an important place in the olfactory palette of perfumers and are at the origin of the creation of many famous juices.

Whether you're a nosey or a neophyte, we're sure you're familiar with these poetic names, to say the least. And for those who don't know, they are simply synthetic odorant molecules - in other words, manufactured in a laboratory - that can be found in your perfumes but also in your cosmetics and sometimes even in your food.

But finally, what are the smells that are hidden behind these scientific names - and unpronounceable for some? To know all the olfactory secrets of the synthetic molecules present in your perfumes, read on!

I. History and definition of synthesis

As you will have understood, chemistry and the discovery of synthesis in the 19th century has resolutely changed the perfume industry. It is thanks to the latter that the industry is as we know it today: rich and with infinite possibilities. But why did synthesis change the industry so much?

In powder, liquid or crystal form, synthetic raw materials have various advantages. In broad terms, they allow perfumers to:

• to recreate at low cost odors found in nature,
• expand their palette with scents that do not exist (food scents) or that are impossible to extract naturally (such as certain woods, certain fruits and certain flowers that are called "dumb" flowers),
• to extract interesting components from a natural raw material,
• to protect animals and replace rare raw materials, sometimes threatened with extinction, and to solve certain problems related to supply conditions,
• and finally, to bring stability to the compositions because of their simple structure and much less complex than their natural friends - which can be made up of more than 200 molecules like jasmine or vanilla for example - while on the side of the synthesis, the chemists choose and use as they wish, the synthetic odorous molecules which interest them for the creation of their juice.

Obtained artificially in the laboratory, using various chemical processes, synthetic molecules can :

• reproduce perfectly the smell of a natural molecule, we speak then of "nature identical".
• be the result of molecules isolated from their natural structure, slightly modified synthetically to give them odorant properties that they did not have originally. In this case, we speak of hemi-synthesis.
• be totally imagined, invented and created in the laboratory. This is called total synthesis and the resulting products are so-called "artificial" molecules.

At Bastille, 5% of our fragrances are synthetic. We know that synthesis is the subject of debate, but for us: natural and synthetic complement each other. Above all, it's a question of balance.

Not everything in synthesis is bad, and not everything in nature is clean. That's why all our ingredients (synthetic and natural) are carefully selected with respect for the planet and your skin, to give life to exceptional accords: you'll find only quality ingredients and, above all, zero endocrine disruptors, phthalates, parabens, solvents, stabilizers, colorants, UV filters and, of course, no CMR-classified ingredients. Fragrance yourself in complete freedom is now possible with Bastille.

To learn more about synthetic molecules: their history, their use, their controversy and how to make sure they are safe, we invite you to our dedicated article! That being said, let's get to the heart of the matter: what exactly does a synthetic molecule smell like?

II. The main synthetic notes in perfumery

Let's go for a little olfactory stroll around the synthetic molecules most used by the Nose.

We would have loved to list all the synthetic molecules and their characteristic smell but out of 4000 raw materials of the perfumer's palette, 90% are synthetically produced - that's a lot but don't panic, you will find in the following article, the most known synthetic molecules. This should be more than enough to shine at your next family dinner!

The precursor: coumarin

Coumarin was the very first synthetic ingredient to be used in perfumery.

A substance of natural origin, coumarin was first extracted in 1820 from tonka beans by Heinrich August von Vogel. It was then synthesized in 1868 by the chemist W.H. Perkin and improved for industrial marketing in 1877. A few years later, in 1882, it was used by perfumer Paul Parquet to create Fougère Royale - the perfume at the origin of the creation of the accord and the so-called "fougère" family (composed of lavender, geranium, woody notes and, of course, coumarin, which is essential to the constitution of this accord).

It is generally found as a base note in many perfumes because it is highly prized for its role as a fixative and its olfactory complexity: at once soft, powdery, creamy and almondy, it can also evoke freshly cut hay, straw or blond tobacco.

Animal notes: amber and musk

The following synthetic raw materials are the result of the framing and/or prohibition of their natural version in perfumery. Coming from animals, animal notes are essential odors in perfumery: often used in base notes, they allow to reinforce other notes already present in perfumes. They bring strength to the compositions thanks to their tenacity and their strength.

On the other hand, if they are replaced today by synthetic alternatives it is simply because they are rare (and consequently expensive) and that their conditions of extraction are not always respectful of our friends the animals. Here are the best known of them:

Ambroxan

In its natural state, ambroxan comes from ambergris, which is none other than the secretions of sperm whales found and recovered dry and hardened on the beaches (yes, yes). Today, this natural raw material is replaced by a synthetic alternative for ethical reasons, price and quality - because the quantity of ambergris harvested each year is very random, as is its quality.

Its synthetic equivalent was discovered by the chemist Max Stoll in 1950 to meet the needs of perfumers: it is by slightly modifying the sclareol - structure of the clary sage - that he discovered that a molecule had a smell close to that of ambergris.

This raw material seduces many noses: very rich and faceted, ambroxan is mostly used as a base note. It offers woody, ambery and even animalic scents, and is highly prized in oriental compositions for its sensuality and warmth.

You can find him in :

• Un Deux Trois Soleilour mischievous oriental from the collection, where amber adds roundness and warmth to the composition.
• but also in Batailleour incandescent woody, where amber reveals more of its woody facets
• and even more surprisingly, in Hors-Pisteour modern, cheeky eau de cologne that perfectly reproduces one of our favorite cocktails: the gin and tonic - in moderation, of course!

Musks

The synthetic musks used today in perfumery smell clean, have a cottony and slightly fruity smell. Discovered in the 50's, the so-called "white" musks, therefore of laboratory origin, replace the musk of animal origin, now forbidden because its harvest could lead to the death of the animal.

A more respectful and cruelty-free alternative, the smell of synthetic musks is nonetheless different from its natural counterpart: in its pure state, the musk of the chevrotin releases an extremely strong and intense smell with woody and animal notes, while laboratory musks smell clean... Natural musk and synthetic musks are different, not equivalent

Other animal raw materials (castoreum, hyraceum etc...) have also been replaced by synthetic (and even natural) alternatives due to their framing or banning - to learn more about this, go to our dedicated article "Animal notes: scandal perfumes".

Aldehydes 

Let's move on to aldehydes. These are synthetic molecules that exist in their natural state, particularly in the zest of citrus fruits.

Introduced for the first time in a synthetic state in fine perfumery in 1921 with the creation of the famous "Chanel N°5", aldehydes are classified by the number of carbon atoms ranging from C6 to C12. According to their number, their smell differs. However, they are all more or less recognizable by their metallic, greasy, warm smell and can be more or less orange, grating, soapy, sometimes with an "iron" effect. They generally give flight and power to floral compositions.

For the more expert, we see you coming! There are indeed aldehydes beyond C12. However, they are not part of this category of molecules previously described. The C14, C16 and C18 aldehydes have different olfactory facets and belong to a completely different family, that of the lactones... But we'll come back to that in the rest of the article!

Vanilla

Gourmand, reassuring, sweet, regressive but also sensual, suave and voluptuous, vanilla and more precisely vanillin (the main fragrant component of vanilla) is a raw material that can be used in its natural state in the composition of your juices. But its long and meticulous extraction process makes vanilla a rare and expensive natural raw material - about 170€ per liter.

Picked while still fresh, vanilla is first immersed in boiling water (scalding stage), covered for at least 24 hours (steaming stage) and left to dry for many months before releasing its sublime fragrance... This is why it is often substituted by synthetic alternatives:

• synthetic vanillin,

• and ethyl-vanillin, a synthetic derivative 10x more potent than vanillin

This challenge of synthetically reproducing vanillin was taken up by two chemists Wilhelm Haarmann and Ferdinand Tiemann in 1874. This discovery was major in perfumery, because it allowed to reduce the costs while keeping the "authenticity" of vanilla.

It is a few years later, in 1920, that ethyl-vanillin, a synthetic derivative of vanillin, makes its appearance on the perfumers' organ. It has the same smell as vanillin but is 10 times stronger. Its price is higher than the synthetic vanillin but remains largely less expensive than the natural vanilla.

It should be noted that vanillin and ethyl-vanillin do not have the same complexity and richness of scent as natural vanilla: the synthetic equivalents give off a more gourmand and sweet vanilla scent, whereas natural vanilla can offer many more possibilities and different facets - warm, smoky, sweet, woody, spicy and even tobacco.

The calone, the smell of the sea spray

Smells of seaweed, iodine, sea spray... The marine notes let out invigorating, fresh, salt water notes that give this feeling of freedom reminding us of the lively sea air.

Blue cypress, lotus, sea fennel, seaweed, oak moss with its iodine tones or even watermelon and melon for their aqueous notes, the marine notes generally present in the top notes of a perfume have arrived safely - in your bottles - thanks to a synthetic raw material: calone (technically called Calone 1951) a synthetic molecule discovered in 1966!

Its structure, similar to that of pheromones produced by certain species of algae, and its aqueous, iodine-like odor, were discovered following a disappointing experiment that was originally intended to result in the creation of an additive for pharmaceutical use.

This unanticipated discovery has definitely allowed perfumers to take the plunge and even discover other synthetic molecules with sea spray odors such as melonal, floralozone or evernyl - a slightly marine wood moss note...

Lactones

Lactones are a family of synthetic raw materials that can be recognized by their fruity, velvety and creamy smell, reminiscent of peach, apricot and coconut. They flooded the perfumery of the years 2000 with notably the perfume Mitsouko of Guerlain - but also the food industry notably in yoghurts or candies for example. Among them, we find :

• the famous Coumarine which, with its notes of cut hay, almond and hazelnut, is reminiscent of the smell of Cleopatra's glue - if you were the type to sniff it in art class, Un Deux Trois Soleil, our mischievous oriental with notes of almond, heliotrope and tonka bean, is sure to please!

• gamma-undecalactone, an apricot or peach syrup.
• Undecalactone delta that smells like warm milk.
• and also Aldehyde C18! Mentioned earlier in the article, this aldehyde is not one of the aldehydes previously described - like C14 and C16 aldehydes, Aldehyde C18 is a fruity, gourmand synthetic note.

The greedy smell of ethyl-maltol

We end on a gourmet note, we named the ethyl-maltol!

A synthetic molecule discovered in 1969, ethyl-maltol is now widely used since the success of Thierry Mugler's great gourmet oriental Angel, launched in 1992.

It is an artificial derivative six times more powerful than its natural friend, maltol, found in cocoa and roasted malt. Its caramel smell, of cooked fruits with praline accents, makes it a molecule widely used in perfumery and is used to create gourmet agreements with sweet, ultra greedy and regressive notes.

Addictive or unbearable (to each his own, after all!), ethyl-maltol remains an omnipresent synthetic raw material of "feminine-gourmand" perfumes.

Now you know what most of the synthetic molecules in your bottles smell like!

In fact, if you'd like to find out more about synthetic molecules and their fragrance properties, you can find the full list of ingredients in our fragrances on our website, along with the role of each synthetic ingredient in the formula! For example, Ethyldecadienoate/cis-4 trans-2 is used in Rayon Vert for its green and pear notes, and Undecalactone - delta is used in Demain Promis for its milky facets and peach notes. We told you you'd become ace synthesizers ;)

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Sources: ScenTree.co, Nez, sylvaine-delacourte.com