Perfume Notes Are Impressionistic

From Reddit r/fragranceAn example of how commercial fragrances are composed [education] [long]” by u/acleverpseudonym. [See also r/DIYfragrance]. Lightly edited for grammar; links added for educational purposes; light [commentary and additions] by me.

Some of you might remember me. I was one of the moderators here for half a decade or so until my life got busy enough that it became difficult to keep up.

I have a small fragrance line myself and I occasionally make fragrances for other brands. Occasionally websites like Fragrantica and Now Smell This will write articles about my fragrances. I’m by no means a famous perfumer, but… I’ve worked enough as a perfumer to have insight into how fragrances are made.

The average person doesn’t really think about what’s actually in their fragrances any more than the average person really considers what flavors blend together to make up the taste of cola. (As a side note, you can make a passable cola flavor out of orange, lime, cinnamon, lemon, nutmeg, and coriander). When people do start thinking about it, they inevitably come across fragrance notes.

Fragrance notes are both incredibly useful and completely misleading because notes are not ingredients! Notes are the impressions that the fragrance creator thinks a lay person might get from smelling the fragrance. They aren’t necessarily the ingredients used in the fragrance, and also, (this is another important bit), they’re not necessarily even what the perfumer was attempting to make the fragrance smell like.

There’s a fundamental misconception on the part of most consumers. Most consumers think that fragrances are made largely from familiar materials. Orange, lemon, jasmine, rose, birch leaves, lily of the valley, etc. Ok, maybe most people realize that most fragrances contain synthetic materials, but there’s quite often an implicit assumption that the synthetics are a synthetic version of a natural material. In other words, that the synthetic is an attempt to recreate a smell that is found in nature and that all (or at least most) of the smells in a modern fragrance can be reproduced with naturals. I suppose that if you asked someone “do you think that all synthetics are an attempt to recreate a natural smell?” they would think about it and quickly come to the conclusion that this doesn’t really make sense, but most people haven’t actually stopped and thought about it. I see evidence of this assumption all over the place online:

  • “I’m looking for all natural version of [fragrance X].”
  • “I’m looking for a less synthetic version of Sauvage.”
  • “Can someone tell me which essential oils I can mix together to make an aquatic smell like Cool Water?”

It’s really only pretty recently that there has been any real visibility (to the general public) into what materials go into a commercial fragrance, so this is an understandable point of view.

It’s very, very wrong, though.

We need to take a giant step back and clarify some things.

Natural oils (essential oils/absolute oils/SCO2 extracts/etc.) are typically made up of dozens to hundreds of different materials [typically distributed in a long-tail]. They’re like miniature perfumes in and of themselves with top notes, heart notes, and base notes. They’re complex and beautiful, but they can only be manipulated in a limited way. They’re like photographs.

Specialty bases are typically made up of dozens of individual ingredients, some natural, some man-made, some that exist in nature, some that didn’t exist until they were created in a lab in the 60s. Basically, the sky is the limit. You generally don’t know exactly what’s in them, but they’re produced by suppliers that you can be pretty sure will still be making them in 20 years. Sometimes, they’re direct attempts to reproduce (or improve upon) a natural smell, for reasons of cost, safety, or performance. Sometimes, they’re just a novel smell, like Givaudan‘s aquatic smelling Ultrazur base. These are like computer generated images [or Photoshop filters].

Isolates are ingredients made of a single molecule. They can be naturally derived or lab-made. They can exist in nature or not. They have names like linalool, coumarin, limonene, ambroxide [better known as ambroxan – the qualia of the day in this video and one of my favorite aromachemicals], methyl dihydrojasmonate and you can describe and find the chemical formula for them. A lot of them have trade names that are shorter and refer to one company’s version. E.g. Hedione is a trade name for methyl dihydrojasmonate. Quite often, isolates can also be found in natural oils. Natural lavender oil is typically ~42% linalyl actate and ~40% linalool [note: lavender oil with more linalyl acetate relative to linalool tends to smell “dryer” and “dustier”]. When composing fragrances, I’ll use linalool and linalyl acetate as isolates as well. Sometimes I’ll use them to “tune” other ingredients that already contain them, but not in the quantities I want (like lavender [e.g. “LAVENDER OIL 40/42 has fresh, herbal, clean, aromatic nuances. The numbers in Lavender 40/42 indicate the linalyl acetate content; in this case, they indicate the product contains 40%-42% of linalyl acetate. Lavender 40/42 is generally a blend of various lavenders in order to get a consistent scent from batch to batch, with processors adding linalyl acetate to cover the smell of camphor or borneol components of a given lavender.“]). Sometimes I’ll use them to add a sweet, floral character to completely unrelated materials. If natural oils are like photographs and bases are like CGI, isolates are like paints. You have the most control, but it takes the most skill to turn them into something beautiful and complex.

Typical Lavender Oil Composition (source)

“Aromachemical” is a catch-all term used to describe these fragrant materials, though it typically connotes materials that are either isolates or bases.

Now that we have that out of the way, let’s take a look at how commercial fragrances are created. The easiest way to do that is to take a look at a formula:

Cologne Accord [which you can find/purchase in Perfumer’s Apprentice‘s “Key Accords“]:

This is an example formula for a “cologne” accord that was composed by Givaudan. It’s by no means a finished fragrance, but most everyone would recognize the smell. It’s a fresh, slightly sweet, slightly bitter, slightly green smell that often finds its way into men’s fresh fragrances in one way or another (though that’s not to say that this exact formula does).

  • Florhydral – 10
  • Exaltolide Total – 10
  • Ultrazur – 15
  • Peonile – 60
  • Petitgrain oil -70
  • Ethylene Brassylate – 90
  • Aurantiol Pure – 100
  • Geranyl Acetate – 120
  • Linalyl Acetate – 220
  • Dihydro Myrcenol – 305

Total: 1000

Lets take a look at these ingredients one by one:

Florhydral is the trade name for an isolate. It is a floralizer that can add a sort of fresh, green, floral note to fragrances. It is not found in nature.

Exaltolide is another single molecule, a white musk. It’s very delicately animalic, with the characteristic smell of a white musk. It’s been used as a reference white musk because it’s so typical of the “white musk” family.

Ultrazur is a specialty base from Givaudan. It’s marine smelling, more oceanic than the Calone 1951 found in Cool Water. By itself, in concentration, it reminds me very much of fabric softener.

Peonile is another “not found in nature” molecule. It has a sort of rosy, sort of geranium-like, sort of peony-like, sort of grapefruit-like odor and acts as a volumizer and fixative. Odor descriptions that call to mind an assortment of known materials are fairly common, but it’s important to note that they don’t mean that it smells like x+y+z. It just means that they have facets that are reminiscent of these materials in some way.

Petitgrain oil is a natural oil made from the greenery of a citrus tree. Usually from orange trees, but varieties from mandarin, lemon, and all sorts of other citrus are also available.

Ethylene brassylate is a sweet, floral, white musk that can smell a touch old fashioned to some people by itself, or in really high concentrations. It’s still a fairly clean musk, however. Yet another single molecule.

Aurantiol is a very, very commonly used material in fragrances, particularly men’s fragrances. It’s a single molecule (more or less). Aurantiol is a Schiff Base, which is a class of materials that you get when you combine an aldehyde and an amine and they react with each other. Most amines don’t smell very good, but one of them, something called methyl anthranilate, does. It’s found in white florals, particularly neroli [see: The Neroli Neighborhood for a deep dive into the neroli vibe], as well as grapes. Artificial grape flavor is basically methyl anthranilate. Hydroxycitronellal is an aldehyde that is often said to smell as close as any single material does to Lily of the Valley. When they’re mixed together and heated, you get water and a very thick, highlighter yellow colored schiff base that smells like a more mild version of methyl anthranilate. It’s sweet, long-lasting, and reminiscent of orange blossom/neroli and grape.

Geranyl acetate is the acetate version of geraniol. It’s a single molecule that is literally found in hundreds of natural oils. Everything from oregano and thyme to ylang ylang, rose, geranium and neroli, to fir needle and frankincense. It’s everywhere (much like linalool and linalyl actetate [note: in addition to lavender, also petitgrain, neroli, and bergamot all have very high concentrations of both linalool and linalyl acetate at the same time]). It’s sweet, fruity-floral, and vaguely green smelling. It also has a smell that I think of as the “acetate smell,” which can make it smell “chemically” to some people in isolation, even though it’s found everywhere in nature.

Linalyl acetate is another material like geranyl acetate that’s found all over the place in nature. Natural lavender oil is ~42% linalyl acetate. It’s also found in most of the natural oils I mentioned for geranyl actetate. The description for it is also very similar to geranyl acetate, but it’s more lavendery and less rosy. I really like this material and use it when I want to add an ethereal fruity/floral sweetness to a composition.

Dihydromyrcenol is aggressively fresh, cold, and almost harsh. It’s somewhat reminiscent of citrus and lavender. Mostly, though, it smells like laundry detergent. It was used to scent laundry detergent for years before it made it into fine fragrance. At first it was used in tiny doses, but by the 1980s it was being used much more prominently. Something like 10% of the formula of Drakkar Noir was dihydromyrcenol [and apparently also the fragrance super-star of the 90s Calvin Klein One]. It’s found in trace amounts in nature, but nothing natural really smells prominently of it.

So now that I’ve explained all the materials, let’s take a look at the formula. Here are some observations:

Natural oils from recognizable sources only make up 7% of the accord. There are other materials that are found in nature, but they’re all isolates, one alien smelling-molecule refined from a more familiar-smelling material. More than half of the formula is made from 2 molecules [once again, long-tails]. More than 90% is made from 8. The amounts of materials used can vary wildly. Material strength is in no way consistent.

The perfumer who composed this formula painted the majority of the formula in broad strokes from single molecule aromachemicals and then filled in depth and details with natural petitgrain oil, and tiny amounts of a specialty base (ultrazur) and a powerful aldehyde (florhydral).

I didn’t compose this, and I can’t speak for the perfumer who did, but I can imagine how it might have been composed. I’ll walk you through how I’m imagining the perfumer’s process:

I imagine the accord was inspired by petitgrain, but the perfumer wanted something fresher and more stylized and abstract, in the same way a graphic designer might prefer a stylized logo to a photo. Dihydromyrcenol is fresh and powerful, but also cold and harsh and almost bitter. It’s a good compliment to petitgrain, but right off the bat, I know it’s not going to be suitable by itself unless I’m trying to just modify the smell of petitgrain a little bit by adding a teeny tiny bit dihydromyrcenol. It needs some cushion, something to cut the harshness. Geranyl acetate and linalyl acetate add a niche cushioning effect, can be used liberally, and are both found in petitgrain, so they’ll go well with it. By itself, that composition is still cold and bitter. It needs a bit more warmth, but not a candy-like warmth. Something keeping in line with the petitgrain. Aurantiol is the obvious choice. The scent of orange tree leaves goes well with the scent of the orange blossoms that nestle amongst them. In keeping with the “more abstract” theme though, we don’t want to just dump neroli or orange blossom absolute into this. Too much complexity can leave a composition smelling muddled [see quote below for more on this], and we want the bitter, fresh, green petitgrain to be the star of the show here, not the neroli. Plus, neroli is quite expensive and not as long-lasting as aurantiol. We add the aurantiol for warmth. The peonile for volume and some white musks for depth. It’s pretty common to use multiple musks in a fragrance because many people are anosmic to some musks, so you want to make sure they’re able to smell at least one of them.

Then as finishing touches, we add a hint of Ultrazur, which adds a bit of modern sophistication and florhydral, which in tiny amounts adds a bit of a dewy, natural, green smell to the composition.

This composition isn’t about taking familiar smells and mixing them together like some sort of fruit salad with hunks of this and hunks of that. It’s about taking an idea and enhancing aspects of it, rebalancing it until it fits the vision. It’s more like painting than making a collage. It’s not necessarily as detailed or accurate, but it’s not supposed to be. Degas wasn’t trying to create photorealistic ballerinas. Van Gogh wasn’t trying to accurately render the night sky. They were trying to evoke an impression. Perfumers are the same way.

If that fragrance doesn’t smell like realistic rose/jasmine/cedar/etc., chances are, it wasn’t intended to. The perfumer wasn’t trying to make a realistic jasmine and failing, the perfumer was trying to make an entirely new smell that just has aspects that are jasmine-like.

Breaking it apart into notes is actually counterproductive in a lot of ways.

…but that’s a subject for another post.


In response to the Reddit r/DIYfragrance question: “Lavender + Lemon + Rose accordHow would you use a lavender + lemon + rose accord? I like that combo a lot – a narcotic acidic mix with powerful mood-lifting properties. But as soon as I use patchouli, ginger, or even chamomile as the base notes for the composition, the magic of the accord gets drowned out by the base. I’m curious how more experienced DIY fragrance makers would go about harnessing the magic of that accord by blending it with things that enhance rather than detract from it. Thank you in advance 🙂

u/NanashiSaito comments:

I’m going to take a shot in the dark here and say that it sounds like you’re using essential oils rather than individual aromachemicals for your accords. 

If that does happen to be the case, that’s your issue. It’s not that there’s anything specific about Rose/Lemon/Lavender that doesn’t play nice with other scents. It’s that essential oils inherently get “muddy” when you start to mix more than a few together. 

Essential oils are a complex combination of hundreds of individual aromachemicals. They’re almost like finished fragrances unto themselves. I look at them like jellybeans. One jellybean tastes like whatever flavor it’s supposed to taste like. Two or three jellybeans can taste like a fun combination of flavors. 

But have you ever tried popping a handful of jellybeans? The flavors all muddle together and create this generic sort of fruity sweetness that doesn’t really taste like anything in specific. It’s the flavor equivalent of swirling together a bunch of colors until you get brown. 

Same with essential oils. For example, lemon and lime essential oil share a ton of common ingredients, mostly terpenes like limonene, pinene, terpinene, Myrcene, etc. But anyone who has smelled lemon and lime knows that they smell very distinct. This is because they have slightly different proportions of these ingredients. Lemon might have 70% limonene, 10% pinene, and 15% terpinene whereas lime has 50% limonene, 5% pinene and 10% terpinene. When you blend them together, these distinct proportions are lost, and with them, their characteristic smells.

Same goes for mixing other different oils: ginger for example also contains a lot of the same terpenes that lemon contains. But it also has a big dose of camphene and zingiberene which give it the characteristic sharp ginger bite. But when you mix ginger with lemon, it throws off the delicate balance of terpenes in the lemon and thus muddies the character. Same with patchouli: lots of patchoulol and guaiene, but also lots of terpenes found in lemon. Same with chamomile: lots of ethereal esters but also lots of terpenes.

In fact, it’s hard to find essential oils that don’t muddy the balance of lemon. Lavender happens to have a fairly close balance of terpenes (in addition to the characteristic lavender combination of Linalool and Linalyl Acetate). And rose is almost all alcohols.

Basically, with each essential oil you add, you also add a large list of other oils you can’t add without muddying your scent. And with lavender/lemon/rose, there’s really not much room to explore if you’re using essential oils only. 

And there’s the rub: if you really want to explore enhancing your scent, you need to get more granular and start using individual aromachemicals rather than entire essential oils into themselves. 

If you’re dead set on using essential oils only, check out I put together a resource with about 200 different essential oils and their constituent ingredients. You want to find ones that use either entirely different ingredient sets than what are found in your main accord (which will be difficult because you’ve really covered a broad swath of ingredients with your combination), or find ones whose common ingredients are in similar proportion (which will also be difficult).

On the other hand, if you’re already using individual aromachemicals and your description of the accord is more abstract than literal, then you probably know all of this, so my apologies for the presumption, and I hope this comment is helpful for anyone else reading this. 

Good luck, and see you in the singularity!

Featured image: San Giorgio Maggiore at Dusk by Claude Monet

Learning the Trade

Excerpt from “Perfume: The Alchemy of Scent” by Jean-Claude Ellena (pgs. 36-38)

Odor Classifications

To help beginners memorize odors, different perfume companies have created various classifications. The one I provide is based around nine categories of odor.

  1. Flowers. They are subdivided into five groups.
    1. Rose Flowers: This group, which includes rose e.o.[1], geranium e.o., and the odor of hyacinth, lily of the valley, and peony, is characterized by the fragrance of two components of these flowers – phenylethyl alcohol and geraniol.
    2. White Flowers: This group is determined by the combination of two molecules – methyl anthranilate and indole – that characterize the absolutes of orange flower, jasmine, and tuberose, but also the aromas of sweet pea, gardenia, and honeysuckle.
    3. Yellow Flowers: This group is defined by the presence of ionone beta, a molecule produced by the breakdown of the pigment carotene, which is responsible for the color of flowers like freesia and wallflower, extracts of which are in cassia absolute and osmanthus absolute.
    4. Exotic or Spiced Flowers: This group is defined by the combination of benzyl salicylate and eugenol, which is present in the odor of carnations and lilies and as a component in ylang-ylang e.o.
    5. Anise Flowers: This group includes mimosa absolute and the odors of lilac and wisteria. They are created using anisic aldehyde or heliotropin.
  2. Fruits. They are subdivided into three groups.
    1. Citrus: Lemon e.o., bergamot e.o., orange e.o.
    2. Orchard Fruits: Aldehyde C-14 (called peach), fructone.
    3. (Soft) Fruits: Black currant absolute, frambinone.
  3. Woods. They are divided into five groups.
    1. Sandal: Sandalwood e.o.
    2. Patchouli: Patchouli e.o.
    3. Vetiver: Vetiver e.o., vetiveryl acetate.
    4. Cedar: Virginia cedarwood e.o., Atlas cedarwood e.o.
    5. Lichen: Oak moss absolute.
  4. Grasses. They are subdivided into three groups.
    1. Green or fresh-cut grass: Hexenol, galbanum e.o.
    2. Aromatic: Lavender e.o., rosemary e.o., thyme e.o.
    3. Aniseed: Basil e.o., tarragon e.o., anise e.o.
  5. Spices. They are divided into two groups: cool spices and hot spices.
    1. Cool Spices: Pepper e.o., cardamom e.o., nutmeg e.o., pink pepper rose e.o.
    2. Hot Spices: Cinnamon e.o., clove e.o., pimento e.o.
  6. Sweet Products. They are subdivided into three groups.
    1. Vanillas: Vanilla absolute, vanillin, benzoin resinoid.
    2. Coumarins: Tonka bean absolute, coumarin.
    3. Musks: Synthetic musks.
  7. Animal Products. They are subdivided into three groups.
    1. Ambers: Labdanum absolute, cistus e.o.
    2. Castoreums: Castoreum absolute, birch tree e.o.
    3. Civets: Civet, skatole, indole.
  8. Marine Products: Seaweed absolute, calone.
  9. Minerals: Aledhydes.

In addition to this classification, I recommend another system for identifying odors. To make it easier to memorize and to conceptualize “odor” as an object, I use words associated with another sense, in particular the sense of touch. So I say of an odor that it is hard, soft, cold, hot, velvety, dry, flat, sharp, silky, prickly, gentle, thin, heavy, light, harsh, fragile, oily, greasy, and so forth.

So the vocabulary specific to olfaction consists of words for aromatic objects (soap, sweet, cigar, etc.), of names of flowers (jasmine, lilac, lily of the valley, etc.), of the names of chemical molecules (linalool, benzyl acetate, hexenol, etc.), or of their function (salicylate, aldehyde, etc.), and of words drawn from other senses.

However, what distinguishes the vocabulary of the perfumer from that of laypeople is the choice of a common language based on the training provided in perfumery schools and the discussions between perfumers and experts within the profession. This linguistic community creates a consensus around certain perceptual features. For the perfumer, soap, aldehyde, jasmine, nail varnish, rose, leather, wood, bonbon, and so forth are terms that describe the odor and not the object that produces it. A lily of the valley can be described as “jasmine”, as can a fragrance, a washing powder, and so on. For the perfumer, the word “jasmine” refers to an olfactory experience, which can be very different from the fragrance given off by jasmine flowers. For the professional, therefore, the vocabulary of odors no longer brings to mind the image of the source but a mental picture of the odor. The perfumer thus invents the object of his science; he invents odor, and that is the source of his creativity.

[1] e.o.: abbreviation for essential oil.

See also these articles that discuss the state-space of scents:

A Big State-Space of Consciousness

Kenneth Shinozuka of Blank Horizons asks: Andrés, how long do you think it’ll take to fully map out the state space of consciousness? A thousand or a million years?

The state-space of consciousness is unimaginably large (and yet finite)

I think we will discover the core principles of a foundational theory of consciousness within a century or so. That is, we might find plausible solutions to Mike Johnsons’ 8 subproblems of consciousness and experimentally verify a specific formal theory of consciousness before 2100. That said, there is a very large distance between proving a certain formal theory of consciousness and having a good grasp of the state-space of consciousness.

Knowing Maxwell’s equations gives you a formal theory of electromagnetism. But even then, photons are hidden as an implication of the formalism; you need to do some work to find them in it. And that’s the tip of the iceberg; you would also find hidden in the formalism an array of exotic electromagnetic behavior that arise in unusual physical conditions such as those produced by metamaterials. The formalism is a first step to establish the fundamental constraints for what’s possible. What follows is filling in the gaps between the limits of physical possibility, which is a truly fantastical enterprise considering the range of possible permutations.Island_of_Stability_derived_from_Zagrebaev

A useful analogy here might be: even though we know all of the basic stable elements and many of their properties, we have only started mapping out the space of possible small molecules (e.g. there are ~10^60 bioactive drugs that have never been tested), and have yet to even begin the project in earnest of understanding what proteins can do. Or consider the number of options there are to make high-entropy alloys (alloys made with five or more metals). Or all the ways in which snowflakes of various materials can form, meaning that even when you are studying a single material it can form crystal structures of an incredibly varied nature. And then take into account the emergence of additional collective properties: physical systems can display a dazzling array of emergent exotic effects, from superconductivity and superradiance to Bose-Einstein condensates and fusion chain reactions. Exploring the state-space of material configurations and their emergent properties entails facing a combinatorial explosion of unexpected phenomena.

And this is the case in physics even though we know for a fact that there are only a bit over a hundred possible building blocks (i.e. the elements).

In the province of the mind, we do not yet have even that level of understanding. When it comes to the state-space of consciousness we do not have a corresponding credible “periodic table of qualia”. The range of possible experiences in normal everyday life is astronomical. Even so, the set of possible human sober experiences is a vanishing fraction of the set of possible DMT trips, which is itself a vanishing fraction of the set of possible DMT + LSD + ketamine + TMS + optogenetics + Generalized Wada Test + brain surgery experiences. Brace yourself for a state-space that grows supergeometrically with each variable you introduce.

If we are to truly grasp the state-space of consciousness, we should also take into account non-human animal qualia. And then further still, due to dual-aspect monism, we will need to go into things like understanding that high-entropy alloys themselves have qualia, and then Jupiter Brains, and Mike’s Fraggers, and Black Holes, and quantum fields in the inflation period, and so on. This entails a combinatorial explosion of the likes I don’t believe anyone is really grasping at the moment. We are talking about a monumental “monster” state-space far beyond the size of even the wildest dreams of full-time dreamers. So, I’d say -honestly- I think that mapping out the state-space of consciousness is going to take millions of years.

But isn’t the state-space of consciousness infinite, you ask?

Alas, no. There are two core limiting factors here – one is the speed of light (which entails the existence of gravitational collapse and hence limits to how much matter you can arrange in complex ways before a black hole arises) and the second one is quantum (de)coherence. If phenomenal binding requires fundamental physical properties such as quantum coherence, there will be a maximum limit to how much matter you can bind into a unitary “moment of experience“. Who knows what the limit is! But I doubt it’s the size of a galaxy – perhaps it is more like a Jupiter Brain, or maybe just the size of a large building. This greatly reduces the state-space of consciousness; after all, something finite, no matter how large, is infinitely smaller than something infinite!

But what if reality is continuous? Doesn’t that entail an infinite state-space?

I do not think that the discrete/continuous distinction meaningfully impacts the size of the state-space of consciousness. The reason is that at some point of degree of similarity between experiences you get “just noticeable differences” (JNDs). Even with the tiniest hint of true continuity in consciousness, the state-space would be infinite as a result. But the vast majority of those differences won’t matter: they can be swept under the rug to an extent because they can’t actually be “distinguished from the inside”. To make a good discrete approximation of the state-space, we would just need to divide the state-space into regions of equal area such that their diameter is a JND.15965332_1246551232103698_2088025318638395407_n


In summary, the state-space of consciousness is insanely large but not infinite. While I do think it is possible that the core underlying principles of consciousness (i.e. an empirically-adequate formalism) will be discovered this century or the next, I do not anticipate a substantive map of the state-space of consciousness to be available anytime soon. A truly comprehensive map would, I suspect, be only possible after millions of years of civilizational investment on the task.