Science and claims about “modern perfumery.”

As a non-science teacher/professor I was surprised that so many students, including ones with majors in a scientific discipline, were more or less “clueless” about the scientific method.  Of course, scientists are not legally bound by it, and I’ve come across a few who really didn’t understand it, so it’s not surprising that students didn’t!  Moreover, one can argue that science is whatever gets into a science textbook that is used at a major secular university, but when one crosses a river by bridge or is considering a surgical operation, one hopes that there is more to it than that!

A book by Thomas S. Kuhn is (or was) considered to be the seminal work on this subject:

I’ll sum it up here.  First, there is a hypothesis, generally put forth by someone with “credentials” (though of course this was not the case before there were any institutions that could provide such credentials).  It should not be put forth on a whim, but after examining all the evidence available.  The person tests the hypothesis, and if there is any inconsistency it must be reworked or abandoned.  If it passes this test, it can be presented to other scientists, at least some of whom should do their own testing to see if indeed it doesn’t appear to be refutable.  Even if it passes that test (and then likely would be regarded as a theory), it can always be refuted at some point in the future.  Thus, there is no certainty in science.  Note that the world being spherical is not a scientific theory, but an empirical observation, which might be used to construct a hypothesis.  The reason why it is spherical requires a scientific hypothesis, assuming you are not guided by some kind of magical/supernatural belief rather than science.

One problem is that many claims cannot be tested, and today many notions regarded as “settled science” are based upon computer modelling and other lines of evidence (such as mostly human-driven global climate change).  In fact, the modelling for climate change includes a small percentage possibility of “existential disaster,” meaning an end to most if not all human life on the planet.  That’s not something, for whatever reason, one hears in the “mainstream media.”  In such situations, the “conservative” position would seem to be not to take such chances, since there is little to gain from it (other that perhaps more profits for those millionaires and billionaires in the fossil fuel industry).   Another important point is that experiments must be properly controlled, meaning one needs to test for any variable that could possibly be at work.  Sadly, I’ve seen situations where this was not done, even though it was inexpensive and easy to do, because the researchers assumed that those variables couldn’t possibly be relevant (they seem to do this because they tend not to question “textbook dogma”)!

Turning to “modern perfumery,” there are some interesting claims that exist in the online community.  One is that some of these olfactory concoctions (in sealed bottles), created by professional perfumers and almost always highly synthetic, could change within less than a year’s time and become much stronger, yet still smell the same!  In this instance, it’s a scientific claim, as all the variables can be measured.  Those who have asserted this claim have provided no evidence for it other than personal experience, which of course is why the scientific method is so important in the first place (that is, people tend to believe things about their perceptions that are simply false – Aristotle, for example, made various and rather simple claims that turned out to be false, such as why certain objects float in water while others sink).  At least one person mumbled something about “maceration,” but this is done by the perfume companies so that there is little if any change once the bottles are put up for sale to the public (certainly within the first couple of years!) – and that’s almost entirely about the smell rather than the strength.

There certainly can be very minor changes within the first couple of years, but nothing that would lead to a much stronger smell that is also perceived by most to be similar if not identical to what the scent smelled like originally.  Now the chemicals and naturals used to make nearly all of these concoctions are well-known and it’s mostly about variations on a theme at this point in history.  Just read the ingredients on a bunch of boxes and you’ll see the same ones, over and over again, listed.  Thus, if someone thinks that linalool, vanillin, and this or that essential oil are going to produce this effect, let him/her go ahead and make that claim.  You can’t say something like, “I predict something bad is going to happen this year,” and then when something does, as it certainly will, claim that it was a scientific prediction.  Your hypothesis must be precise.  In this case, one should be able to identify exactly what is going to occur within the first year that will lead to a stronger but otherwise identical scent.  And remember, it is the aroma chemicals that are nearly always responsible for the strength of a scent, at least beyond the top notes (and naturals being the main strength factor in a scent’s top notes is likely true for very few), so if you are smelling the usual molecules like linalool and vanillin when you first buy the scent there would have to be more of those to produce a stronger scent.  Where would these molecules originate?  What process could possibly create more of those in a sealed bottle?

Science has a technology to measure these molecules, MS/GC, which provides researchers with a graph showing the amounts of these molecules.  One simply can perform the test before and after the perceived significant strength increase.  It’s neither difficult nor expensive, in terms of scientific testing.  If the claim were accurate, in fact, it would be of especial interest to perfume companies, because it would mean they could save quite a bit of money, just as if you could put gold flakes in a sealed container (with some perfumer’s alcohol, linalool, etc.) and come back less than a year later, then lo and behold, you have more gold!  Instead of thinking such things through, though, some people prefer to mock those who point out how ridiculous (and truly worthy of mockery, presumably) this kind of claim is!  Even with wine, where the product is largely if not entirely natural and more chemical reactions occur after the bottle is sealed, the winemaker has a good idea about when to put the product on the market and how long it should be “aged” before opened.  For example:

Imagine if you could buy an expensive wine and figure out how to make it stronger over time without any other changes occurring (sealing it yourself with one of those vacuum devices that are cheap and effective)?  You could then dilute it with water and save a lot of money!  Isn’t it likely that winemakers would have figured this out already?  Perhaps this largely “boils down” to self-awareness.  That is, some people simply can’t seem to imagine that their sense of smell is so malleable, even if those whom they criticize have cited scientific evidence on that point!  New research suggests the opposite is true, that is, we are much less aware of “reality” than we’d like to think.  One book on this subject is “The Master and His Emissary” by Ian McGilchrist, for example.  And this is quite interesting:

According to Morsella’s framework, the “free will” that people typically attribute to their conscious mind — the idea that our consciousness, as a “decider,” guides us to a course of action — does not exist. Instead, consciousness only relays information to control “voluntary” action, or goal-oriented movement involving the skeletal muscle system. or

Perhaps a major issue in this context involves emotions, which aren’t well understood either (one example I use is the guy who gets angry at how “emotional” his wife supposedly is, but he fails to recognize that anger is a strong emotion!).  For example:

“If you get a warm, fuzzy feeling after watching cute cat videos online, the effect may be more profound than you think, according to research. The Internet phenomenon of watching cat videos, from Lil Bub to Grumpy Cat, does more than simply entertain; it boosts viewers’ energy and positive emotions and decreases negative feelings, investigators say.”

So it may be that believing in all kinds of apparently magical notions about fragrances makes people feel “warm and fuzzy,” whereas thinking that their sense of smell may be may be like Heraclitus’ river (“one cannot step in the same river twice”), generating negative emotions, perhaps rather strong ones!  Thus,magical notions certainly may be psychologically helpful, but science can’t help you understand the world if you allow emotions to rule the day!

NOTE:  Le Labo has a statement about maceration:

All our perfume concentrates are maturated for more than 2 months, enabling each raw ingredient to fully equilibrate within the formula. This is an important step in assuring that the fragrance has settled into the olfactive perception desired by the perfumer. Maceration usually follows maturation and begins when the essential oil is mixed to alcohol. Raw ingredients need to equilibrate with its new host. Le Labo products are freshly weighed at order, in front of you for you. The oil will macerate over a product specific period that can last as long as 2 weeks. Slight olfactive evolution can occur within this period.

As is pointed out, this process is mostly about how blended the scent will be, not about how strong it will be.  Moreover, almost all of these concoctions are largely perfumer’s alcohol (about 90% or more is common).  However, some people seem to prefer living in a magical kind of world, presumably, and so they make up silly arguments.  Notice how when challenged they have no interest in doing the obvious things they could do to demonstrate scientifically that they are correct!

UPDATE:  A recent review of Aventus (at is yet another example of this alchemical notion:

…all this talk about reformulation and longevity i ll give you my personal experience with my 2015 batch. honestly when i first got it i thought it was a fake bottle because i was getting 2 hours of longevity and zero projection. it was also all vanilla pineapple with no birch. fast forward 5 months i have about 85 percent of this juice left and let me tell you even two spray is too much with this stuff. i get the nice fruity top with the ashy smoky woods in the drydown. i can smell this stuff even after a shower. dont know exactly what happened but i ve read others with similar experiences.

At least in this case the person realizes he wasn’t smelling the notes in the same way, but the notion of a magical change to make it much stronger remains.  When I was a newbie, this was the experience I had with Jacomo Rouge. I couldn’t smell much of anything beyond the top notes but then some months later I was able to detect the sweet sandalwood drydown.  As the old saying goes, “you mind might be playing tricks on you!”

UPDATE #2:  One blogger who has argued that these concoctions (in sealed bottles) can get much stronger, claiming that oxidation is the cause (though a fragrance chemist I spoke to recently told me that was ridiculous) has continued to advance this belief:

…I’m going to go ahead and say that no, this isn’t my imagination. My Kouros got stronger – much stronger. And that’s a good thing, especially with less than an ounce left until I’m spritzing fumes.

Here is a scientific paper on the subject which sheds some light on the chemical reality:

Terpenes are widely used fragrance compounds in fine fragrances, but also in domestic and occupational products. Terpenes oxidize easily due to autoxidation on air exposure. Previous studies have shown that limonene, linalool and caryophyllene are not allergenic themselves but readily form allergenic products on air-exposure…

If you aren’t aware, limonene and linalool may be the most common components of the kinds of scents most aficionados wear, and they are not used in tiny amounts most of the time either!  However, preservatives are used (BHT is common, and quite strong) to prevent deterioration of the scent.  Moreover, there is always a little air in the common sealed bottles (so that if air exposure was a major issue, all scents would “spoil” quickly), and using even an ounce in a three ounce bottle is not going to make any major difference in this context.  The researchers did not disclose in the abstract if preservatives were used in their study, but it would have been counter-productive for them to use any (and it would have been academically inappropriate not to mention it).  Evaporation can make a scent a little stronger, if that evaporation is extreme, which would mean something like a three ounce bottle containing perhaps a couple of ml, nearly all three ounces evaporating.  However, the fragrant portion also evaporates, so where is this extra strength supposed to originate?  The evaporation in a sealed three ounce bottle of Kouros, for example, even if it amounted to a few ml with two and half ounces remaining, would be insignificant (and in most modern, sealed bottles evaporation will be nearly nothing), in terms of making the scent significantly stronger.

Certain scents could change due to poor storage and smell “off,” but that is almost always just a top notes phenomenon (I’ve got a few bottles with this issue – they smell like varnish for a little while – all are splash bottles, IIRC).  Perhaps the most interesting implication for this blogger’s claim is that one could more or less turn lead into gold!  That is, you could buy bottles of Chanel No. 5, Shalimar, etc., then decant them into bottles without putting the top on (you could use coffee filter paper and a rubber band to keep dust out).  After a few months or so, you would have something much closer to a Pure Parfum, Extrait, etc. formulation, which costs a whole lot more!  And according to him, you’d only have to give up something like a quarter or half ounce of your three ounce bottle (even if it was a 1.5 ounce bottle you would be getting quite a good deal, especially with vintage formulations, presumably – due to “better” ingredients with many of these).  So, whether he wants to admit it or not, in the fragrance market, his claim is “alchemical,” for all intents and purposes!  Note that in all the Kouros bottles I’ve had since 2008 (at least 7, and all with”chrome shoulders”), one spray to the chest was either strong or incredibly strong, depending upon my sensitivities at the time (some where half full 100 ml, 80% of 50 ml, nearly full 50 and 100 ml, etc.).




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Filed under Criticizing the critics.

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