The evidence register · The Science

The Science: the evidence

The claims The Science makes, as it makes them today: 74 sourced, 76 labelled for what they are, 45 unsourced.

The whole register · the page itself

The molecules that changed everything

The Molecular Explorer

The Great Paradox

  • sourced C₁₀H₁₈O arranged in exactly the same way. · PubChem Compound Summary for CID 6549, Linalool
  • sourced C₈H₈O₃ as the section states it · PubChem Compound Summary for CID 1183, Vanillin
  • sourced Dior’s Eau Sauvage (1966, Edmond Roudnitska) is often cited for its use. · Osmothèque, Conservatoire international des parfums
  • unsourced You’re smelling hundreds of individual molecules hitting your olfactory receptors simultaneously.
  • unsourced Rosa damascena oil contains hundreds of identified compounds, among them:
  • house interpretation It means we know exactly what we’re making — and we can make it the same way every time.
  • house interpretation Synthetics expanded the perfumer’s palette far beyond what nature could supply.
  • perfumery convention Aldehydes often smell fatty or citrusy, esters fruity, alcohols fresh, ketones sweet or powdery. A small change in structure can change the whole scent.
  • perfumery convention The pyramid follows volatility more than any rule.
  • sourced The two mirror forms of some molecules smell different. Same atoms, different arrangement, different smell. · Genva M, Kenne Kemene T, Deleu M, Lins L, Fauconnier ML
  • unsourced Your nose has several hundred types of olfactory receptors. Each molecule activates a combination of them.
  • unsourced At high concentrations, indole smells fecal — it is one of the molecules in that smell. But at the trace levels found in jasmine, it creates that heady, narcotic, almost scandalous quality that makes jasmine so intoxicating.
  • house interpretation Your nose is a remarkably fine chemical detector.
  • unsourced You have several hundred types of olfactory receptors. Each odor activates its own combination — like a barcode.
  • sourced Some people cannot smell certain molecules (specific anosmias) — Iso E Super is a well-known case. This is one reason perfume smells different to everyone. · Genva M, Kenne Kemene T, Deleu M, Lins L, Fauconnier ML
  • unsourced Smell adapts quickly. After a while you stop consciously perceiving a constant odor.
  • unsourced Much of what you call “taste” is actually retronasal smell. Block your nose, and coffee tastes like bitter water.
  • unsourced Built from isoprene units (C₅H₈), terpenes are one of nature’s largest aromatic families.
  • unsourced A rose absolute can yield hundreds of peaks on a chromatogram — each peak a distinct molecule.
  • unsourced The “Flavor Dilution Factor” (FD) reveals true impact — a trace compound can outrank one present in far greater amounts.
  • unsourced Hundreds of volatiles have been identified in wine.
  • house interpretation An effect no single natural material gives.
  • unsourced Woody and velvety. Some people can barely smell it — partial anosmia.
  • house interpretation It is widely linked to the marine fragrances of the late 1980s and 1990s, Issey Miyake’s L’Eau d’Issey among them.
  • house interpretation A synthetic facet of ambergris, central to many recent masculine fragrances.
  • unsourced Its persistence in the environment is monitored and debated. Still used because little else smells quite like “clean.”
  • house interpretation Its generous use in Mugler’s Angel is widely credited with opening the gourmand category.
  • unsourced The bacteria living on your skin can transform some fragrance molecules into different compounds, which is one proposed reason a perfume can smell different from one person to the next. Your skin is a living surface, not a blotter.
  • house interpretation Much of a bottle’s price is marketing and packaging rather than the liquid.
  • unsourced Some fade from awareness in minutes, others take far longer. Whether the coffee beans on the perfume counter help is doubtful — they may not “reset” your nose at all.
  • unsourced It can float in the ocean for years, oxidizing into a complex, animalic-sweet material. Its legal status differs from country to country.
  • unsourced Androstenone, Iso E Super and some musks are well-known cases. For β-ionone, genetic variation changes how people perceive it.
  • house interpretation A fine fragrance can contain dozens of ingredients, a masterwork many more. But the palette available to perfumers is finite.
  • house interpretation A safer return for the brand.
  • unsourced Now largely replaced with synthetic civetone for ethical reasons.
  • unsourced From the musk pod of the male musk deer, a protected species whose trade is controlled. The “holy grail” of animalic notes, and the reason perfumery turned to synthetic musks.
  • house interpretation A complex natural with a very low yield.
  • sourced Studies have found scent-triggered memories often more emotional and older than memories cued by words or pictures; the olfactory system’s close links to the amygdala and hippocampus are the usual explanation. · Herz RS
  • house interpretation Skanky ouds, smoky leathers, medicinal notes can become beautiful with repetition. What you dislike today may become your signature.
  • sourced Paul Parquet used it in Fougère Royale for Houbigant, which gave its name to the fougère family. · Kleoff M, Kiler P, Heretsch P
  • unsourced In commercial perfumery, the fragrance concentrate is a small share of the retail price.
  • sourced Iris rhizomes dried and aged for years, then steam-distilled. · Crișan I
  • sourced Some naturals are restricted by the IFRA Standards (the industry’s own rules, which are not law in the US) and, for a few of their components, by EU law, because they can sensitise skin or react with sunlight; natural musk came from an animal now protected… · International Fragrance Association (IFRA)

The Olfactory Pyramid

  • sourced Small, lightweight molecules like limonene (C₁₀H₁₆, the lemon molecule) have high vapor pressure — they evaporate rapidly at body temperature and are gone within minutes. · PubChem Compound Summary for CID 22311, 1-Methyl-4-Prop-1-En-2-Ylcyclohexene
  • sourced Large, complex compounds like muscone (C₁₆H₃₀O, 15-membered ring) have vanishingly low vapor pressure — they can linger on skin long after the rest has gone. · PubChem Compound Summary for CID 7160826, Muscone
  • artistic visualisation Top, heart and base, hatched denser toward the base: drawn in-house
  • perfumery convention hours to a day and more
  • perfumery convention A fragrance’s sillage is something else: the scent wake it leaves behind as its wearer moves through the world.
  • house interpretation Composing this temporal architecture deliberately, in full knowledge of the molecular physics, is one of perfumery’s great technical achievements.

The Ghost Molecule

  • sourced ISo E Super (1-(2,3,8,8-tetramethyl-1,3,4,5,6,7-hexahydronaphthalen-2-yl)ethanone, molecular formula C₁₆H₂₆O) was first made in the early 1970s by the chemist John B. · PubChem Compound Summary for CID 1808124, 1-
  • house interpretation Iso E Super sits — by industry lore, no measured count — in a great many contemporary fine fragrances, Molecule 01 most famously.
  • unsourced Hall is also credited with Cashmeran.
  • sourced Why some people miss it: a specific anosmia is usually explained by differences in the olfactory receptors a person carries. For Iso E Super the details are still being studied; what wearers report is the experience below — a scent that seems to vanish for… · Genva M, Kenne Kemene T, Deleu M, Lins L, Fauconnier ML
  • unsourced Thought to be genetic. Published prevalence estimates vary widely; none is quoted here until a peer-reviewed source is cited.

More Accords

  • perfumery convention It sits at the heart of many oriental fragrances, giving warmth, depth and a skin-like sweetness.
  • house interpretation Patou’s Joy and Piguet’s Fracas are its classics.
  • house interpretation Before Mugler’s Angel it was widely thought vulgar.
  • house interpretation The clash of sweet and dark shaped a generation of caramel, coffee and vanilla fragrances.
  • perfumery convention Germaine Cellier’s Vent Vert for Balmain made it famous with generous galbanum and violet leaf.
  • house interpretation It shaped the “fresh” aesthetic of the 1990s, L’Eau d’Issey among its examples.
  • perfumery convention Historically built with rectified birch tar (now held to a purity specification by an IFRA Standard, the industry’s own rules, not law in the US), castoreum (now replaced by synthetics) and smoky phenolics.

The Olfactory Laboratory

  • sourced 5 — Chanel (1921) · Osmothèque, Conservatoire international des parfums
  • sourced Shalimar — Guerlain (1925) (from the record) · Osmothèque, Conservatoire international des parfums
  • unsourced Aventus — Creed (2010)
  • sourced Shalimar: 1925 (from the record) · Osmothèque, Conservatoire international des parfums
  • sourced Mitsouko: 1919 (from the record) · Osmothèque, Conservatoire international des parfums
  • sourced L’Heure Bleue (1912) · Osmothèque, Conservatoire international des parfums
  • sourced Vol de Nuit (1933) · Osmothèque, Conservatoire international des parfums
  • sourced Eau Sauvage (1966) (from the record) · Osmothèque, Conservatoire international des parfums
  • sourced 1972 as the section states it · Osmothèque, Conservatoire international des parfums
  • sourced 1944 as the section states it · Osmothèque, Conservatoire international des parfums
  • illustrative example $1.50 as the section states it
  • illustrative example $2.50 as the section states it
  • illustrative example $0.15 as the section states it
  • illustrative example $0.25 as the section states it
  • illustrative example Luxury Niche (100mL/$320)
  • illustrative example Designer EDT (50mL/$85)
  • illustrative example Extrait (30mL/$450)
  • illustrative example Mid-Range (75mL/$200)
  • illustrative example $50–150 as the section states it
  • illustrative example $150–300 as the section states it
  • illustrative example 22°C as the section states it
  • illustrative example 18°C as the section states it
  • house fact Thirteen tools for exploring how fragrance behaves — diffusion, evaporation, colour associations, classification, care. Each is a simplified model, and says so.
  • house fact A simplified particle picture of a spritz spreading through still or moving air (modeled, not a physics simulation). Lighter, more volatile molecules spread and fade first. Warmer air spreads them faster.
  • unsourced Lighter molecules diffuse faster: limonene (136 g/mol) before linalool and geraniol (154 g/mol), before patchoulol and ambroxan (222 and 236 g/mol). Molar masses from PubChem; the particle speeds on screen are modeled.
  • house fact It compares your blend with a set of fragrance families and names the closest (the house’s own model).
  • unsourced Many people link smells with colours, and studies find shared tendencies across groups — an evocation, not a rule (a lemon is not “science-says” yellow). This painter uses the house’s own mappings to render your blend as abstract colour. Select notes and…
  • house fact Twelve questions of the house’s own design map your scent preferences to fragrance families, notes, and famous perfumes worth smelling. A starting point for your nose, not a test.
  • house fact Your own prices go in; the sprays per millilitre are modeled (8, 10, 12 and 15 by concentration), and the presets are example prices, not quotes.
  • house interpretation Wrists — Classic; rubbing them together is said to dull the opening
  • house interpretation Don’t rub — Let it dry on its own; friction warms and hurries the top notes
  • house interpretation Good storage keeps a fragrance close to how it left the bottle for much longer.
  • house interpretation Avoid bathrooms (humidity + heat) and windowsills. Keep it cool and steady.
  • house interpretation An unopened bottle ages most slowly
  • house fact The score is the house’s own model, a nudge rather than a verdict.
  • house fact Browse the house’s office-friendliness opinions, based on projection,
  • house interpretation Fragrance is personal: a small sample or a travel size lets them try it on skin before a full bottle.

Scent, Memory & Emotion

  • unsourced In Swann’s Way (1913), Proust described how the smell of a madeleine dipped in lime-blossom tea triggered a complete, involuntary return to his childhood.
  • sourced The usual explanation: smell reaches the brain’s memory and emotion regions by an unusually short route, and studies have found odour-cued memories often more emotional than memories cued by words or pictures. · Herz RS
  • unsourced Body odour is shaped in part by genes of the immune system (the MHC), and some studies suggest people prefer the scent of partners with different MHC profiles; the evidence is mixed. Perfume changes this signal more than it hides it.
  • sourced A 2014 study (Bushdid and colleagues) estimated that people can tell apart more than a trillion odour mixtures; a later critique argued the maths overstates it, so treat the figure as vivid rather than settled. Either way, the nose encodes smells… · Gerkin RC, Castro JB
  • sourced The Proust effect — the involuntary, vivid memory a scent can bring back — is a well-known idea in the science of smell, and one that researchers have tested in the laboratory. · Herz RS

Dilution Calculator

  • illustrative example 10% as the section states it

Building an Accord

  • perfumery convention A rose accord can contain no rose absolute at all — a construction of citronellol, geraniol, phenylethyl alcohol and damascones that the nose reads as rose. An accord is a question of proportion: drawn in-house
  • perfumery convention Many perfumers think in three roles: the body (the dominant note, most of the accord), the modifier (a smaller part that shapes and colours it), and the enhancer (a trace that makes everything smell more itself). The enhancer is often unexpected — a touch…
  • house interpretation A few percent of ambroxan can make the other ingredients seem to project further and last longer without adding a distinct note of its own.

Extraction Methods

  • perfumery convention Steam distillation loses much of jasmine’s character; solvent extraction captures what distillation misses.
  • sourced Bergapten — a furanocoumarin in bergamot that reacts with sunlight on skin — can be removed to make the “FCF” (furanocoumarin-free) grade perfumers commonly use. · International Fragrance Association (IFRA)
  • house interpretation Supercritical carbon dioxide acts as solvent at high pressure, producing pure, true-to-nature extracts with little or no solvent left behind. Increasingly used for fine ingredients.
  • perfumery convention Lily of the valley gives no usable oil, so muguet (lily of the valley) fragrances are compositions built from analyses of the living flower.

Fragrance & the Mind

  • house interpretation Here is what the evidence actually supports. The old promise of scent as remedy, drawn in-house
  • sourced Smell reaches the brain’s emotional centres by an unusually short route. · Herz RS

The GC-MS Decoder

  • unsourced But gas chromatography–mass spectrometry can separate a mixture into its components and identify most of them, and houses routinely analyse each other’s launches.
  • unsourced The result is a chromatogram: each peak a compound, identified from its mass spectrum, with a rough idea of how much of it there is.
  • house interpretation A trained analyst can read much of a commercial fragrance this way. The large houses run their own instruments; independent perfumers can use university facilities or commercial analytical labs.
  • unsourced What GC-MS reveals: Most aroma chemicals present above trace levels.
  • house interpretation Houses analyse significant launches as a matter of course. Inside the industry it is called market intelligence, not espionage — and “secret formulas” are more transparent to anyone with the equipment and training than the marketing suggests.

The Lab

  • house interpretation Learn these three and you can read many modern formulas. Fougère, chypre, oriental: three structures, drawn in-house
  • perfumery convention Fougère Royale · Azzaro Pour Homme · Drakkar Noir · Brut · Cool Water
  • house interpretation The warmest, richest structure in the perfumer’s palette.
  • unsourced Shalimar — in the house’s legend, an existing composition to which Jacques Guerlain added a large dose of vanillin — remains the archetype.

Projection Estimator

  • modeled A rough estimate of how far a fragrance projects with its concentration, the temperature and where you apply it. Every constant in it is modeled, not measured. The three zones around a wearer, drawn in-house
  • perfumery convention Eau de Cologne (typically 2–5 %)
  • perfumery convention Eau de Toilette (typically 5–15 %)
  • perfumery convention Eau de Parfum (typically 15–20 %)
  • house interpretation Pulse Points: Wrists, neck, behind ears — warm skin lifts a fragrance sooner but spends its top notes faster.
  • unsourced Temperature Effect: Warmth speeds evaporation, so a fragrance projects more on a hot day and fades sooner.
  • modeled the zones, bar widths and durations are the house’s simplified model; real projection varies with the formula, the skin and the air.

Your Skin Changes the Formula

  • house interpretation The same formula can smell different on different people — and on the same person from one day or season to the next. One drop on a paper strip, one on skin: drawn in-house
  • unsourced Healthy skin is slightly acidic, and its chemistry varies from person to person. Perfumers commonly observe that dry skin lets a fragrance fade faster and oilier skin holds it longer; how much pH itself changes a scent is less clear.
  • unsourced It is one proposed reason two people wearing the same perfume smell different: their bacteria may transform some of its molecules differently.
  • unsourced What you eat and your hormones can change the volatile compounds your skin gives off, so a fragrance may wear differently over a week or a year. Claims that particular hormones favour particular notes go beyond the evidence.
  • unsourced After a few smells of the same material your nose adapts and you briefly stop noticing it. This is why perfumers step into fresh air between samples; whether the coffee beans on the counter help is doubtful.

Olfactory Thresholds

  • unsourced The concentration at which a molecule first becomes perceptible differs enormously from one odorant to the next.
  • house interpretation A modern synthetic often used generously; some people barely perceive it
  • unsourced Strong at very low concentrations; the signature of the aquatic family
  • unsourced Violet reconstructions; known for fading from notice quickly as the nose adapts

The Captive Molecule Catalog

Aroma Chemicals Reference

from the house’s claims register and the records, checked against the pages’ own words when the site was built