The Smelly Science of Perfume

jokes lately on faceboo. Nice cheesy science related jokes. There's no reason that scientists can't be humorous, and there's no reason that scientists can't smell fabulous, right, right, right, So today we're talking about the science of perfume, and I wanted to talk a little bit about the worst smell that you like, you know, sort of the smell you're not supposed to like, but you do. Um. For me, it's it's kind of weird cont that, but go on, well, you know, you know it smells bad for you're not

supposed to be sniffing it. You know, I'm not talking about you know, sniffing something to get you know, an effect, but just you kind of like the smell of it, like gasoline is mine. Okay, It's like I'm not talking about huffing, but gasoline smells fabulous. But I do like it also on that vein rubber cement. Okay, okay, but that's perfect sense. Wait what's yours? Um Well, I mean I'm one of these people I tend not to think

of like smells. I like is being like horrible. Um well, like one example, okay, during fruit kind of gets a bad rap for being a dozen indeed, have you ever eaten one? But yeah, that's the thing. It's like I finally got to try it when my wife and I went to Thailand and and Grant, we were outdoors in a we're well ventilated area and okay, everybody's just like

our daurian fruit. The smells horrible, blah blah blah. I mean not the people have sold it to us, obviously, but but you know, you hear that especially here in the States, and um and I really wanted to try it and give it a fair shape because I'm kind of thinking like this kind of like Western you know, chauvitism. It's like, you know, saying I don't want this fruit. You're an equal opportunity for you. So I gave it

a shot and it was it was really good. I mean, it's I think the thing with the Durian fruit is that you kind of have to go into it expecting more of a cheese like it's some sort of a

cheese fruit kind of a thing. But really, yeah, but in terms of things that, like, I guess I do have to admit that I now remember that like sometimes like when I'm painting, like painting, like house painting and stuff like, there is something kind of nice about that smell, like it almost kind of smells chocolate somehow to me, like I should eat it. Yeah. Well, I think it also has to do with a texture of the paint a little bit. You know, it has that like thickness

when it's going on. And and I guess we do tend to paint like the painting jobs I've been on, it tends to be kind of like a brownish or a tannish you know, or like even like a white chocolate kind of color. Stuff. Okay, Well, technically that could be a perfume, because perfume is a pretty I mean, you can define pretty much anything as a perfume. It's a pretty loose definition. It's basically something that you wear and something that smells. I mean, I'm sure the professional

perfumers out there I have a more rigorous definition. But for our purposes, like you don't count like Irish spring is a perfume, but it doesn't necessarily have to smell good or good to everyone. Right, Definitely baste on some of the perfumes I've smelt on public transportation, Yeah, no doubt.

So for our purposes, let's talk about liquid perfume. You know, the stuff you're gonna find in a bottle um, you know, a sprayer spitzer um, and that's just going to be a combo of alcohol, water and whatever key ingredients that evaporated room temperature that you you know, want to throw in to make your signature fragrance. And when you're smelling perfume, you're really just sniffering a bunch of evaporating molecules. Right.

Your nose detects perfume and it sends a message. Shear brain creating this perception good, bad, and different, whatever it may be. And you know that's what's going on in the elevator. Have you ever had this experience, I know all of you listeners. Definitely. Have you walk into the elevator, you know, somebody gets on at the next floor. They walk in in with them trills this just ragrant cloud of cologne or perfume. And I won't say it's women or ladies or men, because you know, I think both

definitely do this. Like there was this one dude that I used to work with him in a before it came to hou stuff works, and it's like I remember the day he came in to apply for his job. It was like, you know that comes in through the door. It's just this stream of just just really strong like cologne was just hanging off of him. And then he left and like the cologne stayed. I think that's when he gave him the job. It's like it's gonna smell impression.

Yeah he did that man made an impression. Yeah. When I was in college, is reminded me a lot of Thursday nights. To me, you'd be going out and you get in a you get an elevator with a with a boy and he would just you know, the whole elevator would smell like dre card noir. Do you remember that cologne? I think I remember. I think maybe my dad had an old bottle of it, and I like found it somewhere and it's like dark looking, right, it's

like dark manly looking cologne, I think. So, like, the more it looks like whiskey, the more it's okay for guys to wear it. Yeah, if I sniffed it now would totally take me back. So what's going on with the individual ingredients in those perfumes, like what's making the car or linger so long? Well, my understanding is that the alcohol works to spread out the different smells, right, allowing you to to to pick up the different hints and the complexities of the perfume. Otherwise you'd be small

on them all at once, right, right. So, writer Susan Nasa, who wrote the article on our site about how how perfume works, was talking about in the in the case of a perfume oil, Um, if you were just to smell that perfume oil, which is a really concentrated essence of the smell, it would kind of be like hearing all the members of an orchestra all play at the same time. Yeah, you're not going to hear the you know, the tuba kind of rumbling. Um. So that that's that's

a perfemale. But the alcohol, right, it allows you to hear or smell, as the case maybe with perfume, all these notes um not at once. It spreads them out like you said, Okay, It's kind of like if you go to Tapas restaurant and like they bring out you know, topless restaurant where it and it's, uh, you don't want all the top as at once in gobl them down in or you want to be there for like a lengthy period of time getting the one by one definitely, definitely.

So in that same vein, it makes sense that a lot of perfumes and when we're talking about perfumes again, perfume does not applied to women or men. It's just it's like we said, a smell um so they have a three part smell and each smell is called a note in the perfume industry, and that's what they like to come. But it's just jargon, and I was not

familiar with this at all before we research this. It's pretty cool, and the smells have different rates of evaporation, so on the top you're gonna have your top note, right, and uh, you're gonna smell these within fifteen minutes of apply. This is where you're gonna find kind of the racy, unpleasant, spicy, weird smell, you know, something that the designer threw into

just kind of you know, be crazy. This is the don't apply your perfume on on the train smell, right when the person next you decides to put it on and you're like cheese and that that's this. This is the top These are the top notes in action, right yeah. Yeah, And and and these are the ones, luckily, that evaporate first. So take us to the take us through the heart notes.

All right, Well, this apparently starts showing up after three to four hours after you've gotten off the train, ideally hanging out at work, and these evaporate more slowly from the skin. The phase of the perfume's life tends to be what this is the This is the phase that makes the most impact. This is what you remember. This is the prime perfume life stage, right, Robert, if you

were wearing a floral perfume, do you wear a floral perfume? Okay, So this is where you find your floral notes, okay, okay, and then you get your base notes, right, and so these form obviously the foundation of the perfume, the base of the perfume, and they linger the longest after you douse yourself in the morning, the five to eight hours

long in a fact. And it's not just the chemistry of the perfume and you know the rate of the molecules evaporating, it's you're a factor to right, So the top notes of the perfume are going to disappear faster if your skin is nice and dry and warm, um, rather than if you're kind of cool and oily. So you're gonna so when you go shopping for a perfume, you need to sort of carry some of the information with you, like, no, am, I you know, but how

my skin is going to behave with it? Sure? I mean, I guess I wouldn't hurt to keep that in mind. And then how you store the perfume is going to affect the chemistry as well. If you store it in bright light, that can impact the bonds and the freegrance molecules and break them um, and then you're you can have bright sun that canna damaged perfume within a week's time. And that was according to a Luca Turan Antonia Sanchez,

authors of the two thousand and eight book Perfume A Guide. Uh, that's the one for the dude Kills All the Ladies, right, No, that's fiction by Patrick Suskin. Yeah. Yeah, the protagonist of that. What is he he's trying to he's trying to. I've seen the movie, I've not read the book. Read Okay, well we complete each other and that then like, um, he I remember correctly, he wants to, like he like falls for these different ladies and like he finds them

into a into perfume. Right, he wants to According to Amazon, I believe captured the scent of a beautiful young version. That's it. That's what he's trying to do. And by version I meant virgin. Yeah. Um, but if it's sort of like Silence of the Lambs but with perfume, what do you think about that? Yeah? Pretty pretty good. The movie was pretty fabulous, pretty really Yeah, it had Dustin Hoffman and it's a perfumest in it. But but back to the storage. Think, what's weird to me about the

whole visible light breaking it down? It's like most perfumes come in like a little glass vials, right, I mean it's true, it's just begging to be broken down by the sun, and they're begging to be displayed, right, I mean because packaging, of course is such a big part of perfume as well. Well, that goes into another podcast that we did on the Smell and Science. Yeah, we've

been on a smelly bender this week. Well, there's a whole deal about how, like how you know, the information from our other senses also affect how we perceive a smell. If you tell me that a cheese is cheese, then I'm gonna respond better than if you tell me a cheese is body odor and and likewise in general, that's it.

That's a good assumption. Yeah, But the thing is, it's like they say that it also ends up applying to like the shape of our perfume container or the like the different the name or you know what are all these different factors that they're using to sell it to you. It's like that you shape it like an apple, even if it doesn't quite smell like an apple. It's like you're gonna be more inclined to think apple when you when you sniff it. Right, So smell being much more

than just the physical act of sniffing. Yeah, So before we move on. I just wanted to touch on. There's one other process that can can harm your perfume, and you guys know this is oxidation. So this is what's going to turn your uncorked wine into vinegar. And it can do a number on your bottle of Chanel number five as well. Okay, So don't keep your perfume out

in a like trough on your on your desk. Yeah, and storing your perfume at room temperature in the dark and in a spray bottle preserves it well, maybe a shelf life of two years, which is interesting because I think I tend to keep my sons much longer than two years. To self, Okay, I gotta go home and clear out the perfumes pomode on the sink. No, I will not do that. So why do we wear perfume?

I found this pretty interesting? Um So, the writer Susan Nasser interviewed this psychologist, Rachel Hurts Uh and she's a she's a Brown University and she's researched smell pretty extensively. It Hurts had a couple of ideas about why people wear these scents. You want to take the men ones? Yeah, and this this makes a you know a lot of sense, like young men wear fragrance to attract women or four men. Um, you know what a preference and uh, of course that

makes perfect sense. And that's like the stereotype too. You know. It's like guys putting on some sort of funky scent generally and on oftentimes maybe not generally, but often not knowing quite what they're doing when when they're picking one out. Um. So that's the young guys and then the older men. According uh, according to Nasser, older men wear it as a nod to the person who gave them the perfume.

In other words, I'm wearing this perfume because i got it as a gift and I've got to use the whole bottle where I'm never going to hear the end of it. And I think you and I think you think it smells nice. So yeah, so I guess as well as nice, I'll wear it. If she likes it, well, we're going out to dinner, might as well. That was myself a little bit. Yeah, generally I don't receive perfumes except from um. Bonnie's grandmother gave me perfume one year. Yeah,

I think we quietly destroyed it. I hope she's not listening. Um So, young women may wear it because of friends, uh and and media influence. This one actually rang true for me. I remember at a certain point in my life in middle school, I think I did start to wear fragrance. And it wasn't because I you know, wait, you probably were, didn't you like wear it earlier? Like you went and like trying on all your mom's perfume

at once? Yeah, that's probably true. I probably did. But you know, I actually bought a bottle from my local drug store or something like baby Softer, I don't even know, some terrible perfume. Not that it's terrible, but I just probably wouldn't buy it now. But it was very much something that all my friends were doing, so it was more like in you know, a reflection of growing up or something to that effect. Um So, her is the psychologists that that a writer interviewed says that women in

thirties do it just because you know, they want to. Uh, once you get into your forties, they're wearing it because they like it. This sounds random to me, though, I mean, you don't like it before and then well, I mean maybe it's kind of like with you know, some people steal with like say beer, you kind of like, you drink beer tastes horrible at first, and then supposedly if you drink enough of it, you start to love it and then you like it takes a while to like

build up in appreciation for it. So maybe it's like you spend your thirties, you know, using these perfumes, but you don't really necessarily like it, but you know, after a while, then you develop this real appreciation for it and then you're, you know, totally into it. That being the case. By sixty again, the women are just wearing it to please others. Well maybe they're just they're just nice old ladies and they're like, I'm just gonna gonna wear this because my son credit for me and they'll

make them happy. Kind of a deal, you know, right, righties are just nice, That's what saying. So sense can affect our moods and our behavior, right, we know this. I mean, it can pull up some sort of treasured memory and it can influence our actions. And there have been a couple of interesting studies in this vein um. I think that you guys have probably heard of the one about the cinnabon. Have you heard about that. We were talking about this a little bit before the podcast. Yeah,

what was to do with this again? It's just the scent of cinamon, right, So put the put the scent of cinnabon in the air, do it, you know, in a mall. Okay, And what you're gonna want to do is you're gonna get some people involved. You're gonna get your participants, and you get one person to drop something and then, um, see if a stranger picks up that pencil, say that you dropped. Well, it turns out if you have the smell of cinnamon in the air, um, people

are more likely to pick up that pencil. The stranger is more likely to pick up that pencil. Good smells as a correlation with you know, good behavior. You know you're going to pick up a pencil, maybe you'll give directions, maybe you're just going to be an all around nice person as long as you're within cinnabons. Wow, it's kind

of interesting, it can. It makes me think of like a futuristic society, you know, where everybody is like a perfect citizen and they're doing it because they're just constantly pumping out the odor of cinnamon. You know what this really made me wonder, and I didn't have time enough to get into it before the podcast, was what do casinos smell like? I'm not a hardcore gambler, but I had to wonder how this sadness, stale cigarettes, sadness and

cinnabone old ladies playing the slats. I don't know, that's really I'm gonna I'm very curious. Now. So there's a study in France that followed a sort of similar cinnamon protocol, only they check to see whether a woman who was wearing perfume would um influenced this sort of similar behavior and strangers so um, you know, she would drop something from her person, she would. They would see if strangers would help her pick up the object, and in fact

they did. You know, the woman wearing the perfume brought out that behavior again she's smelt like cinnamon. No, she smelt like a different perfume. No they did not. Well, see they should combine these two studies, right, maybe they have them. It has the best I act if it's a cinnamon for fume. And then there's just one final

study that I'll get you here. There's a study published in the Journal of Psychological Science, and that found that a citrus scented cleanser was associated with people behaving more fairly when they played a game, a classic trust game. According to this article on the Boston Globe, like apples to app sir, what I don't know, I don't know what the game was. Yeah, so fair behavior, people picking up pencils for you. I mean, it does seem like

scent can influence action. And and that's just you know, a smattering of studies that have been done there. There are many more to explore. But let's let's take a break from that and look at the genetic side. So each of us has a genetically determined number of odor receptors or cells in our nose that grab fragrant molecules out of the air around us. So, with more receptors for a classic compounds like say lily smells, you're gonna smell lily at a lower concentration, but at normal amounts

the smell could be intense and overwhelming. Alright, But too few receptors can be a problem. Why is that? Well, for example, cilantros fragrance consists of many odors. If your genetic code spells out of variation that reduces your number of receptors for an odor. You may miss one of Cilantro's many odors and it may smell soapy to you. We've got touched on this before, Yeah, we did on the genetic stuff. They're talking about it tasting soapy and

of course sent and taste or blood brothers. Indeed, So let's get to the evolution side. And one question that people have thrown out a lot are you know, are our old factory likes and dislikes programmed? And there's pretty

healthy argument on this area. So on the pro side, some people are going to argue that the answer as to whether we like certain smells isn't really genes but history, right, um, and you know, way way way back history like Grays, like just foraging for food kind of things like like I smell fruit, I eat fruit, fruits great. I wish everything smells like fruit. Is the center bund thing again?

Yeah totally um, yeah, right, so that kind of harkens back to our foraging days are hunting and gathering days. And then you know, on the other hand, we're not gonna like the smell of you know, urine feces or you know, maybe rotten or fishy smells, because like urine could like it could be telling me that somebody else's territory, um, you know, fecal all that's gonna potentially parasites and pathogens two sees infectious agents, right, So there could there be

an evolutionary mechanism at work there. That's that's one thought school of thought on this. I'm I'm game to believe that. What about the other side of the argument, Well, yeah, there's the other side of the argument says it smells are an evolutionary programmed and this is this is kind of like the sort of short, short and dirty version of this is like people can get used to anything, right, Your culture preference, your personal experience can override any smell.

I mean, if you grow up with the latter and smell, maybe it's not going to bother you. Yeah, you grow up, you know, gutting fish, then the fish smell is not going to bother you. Back before the days of refrigeration, um now, Sir writes in her article, the smell of rotten meat was tolerated and even liked in Europe. Huh yeah, I guess I just don't really have a perception of rotten hamburger meat per se, just because the refrigerator does

play such an important role. Well, one example that comes to mind, it's like I don't know if you know here, go to like like sort of foreign or not even foreign, but just kind of like I guess, like sort of Asian like kind of like fish markets and stuff, or I guess just any fish market. It's like, I'm not around them, so when I go to them, it's it's a bit overpowering. But I'm thinking, like people a people were around it a lot are going to be more

less inclined to think it's stinky. And also if it's like more like a cultural thing, you're going to tolerate it more. Yeah, or maybe even you know, say you're a smoker, right, you know how smokers can smell themselves, but if you walk into an elevator with a smoker, you can instantly smell it. Or if you're riding the train with somebody who you know, hit happy hour, maybe they can't smell the alcohol on them, but I mean it just waffs over to you on a giant cloud

of dirty martini. Yeah. Yeah, So anyway, So so that's really the other side of the argument is that, Yeah, like you were saying, we can override any of these preferences, and evolution really doesn't have a whole lot to do with smell. So I think we gave you guys a lot of odor for thought. Yeah, I mean, I'm I

think it's. Yeah, next time you're throwing a little perfume, you might think about it a little differently you and also like maybe even like go ahead and mark down on your schedule, like which phase of the perfume is gonna is gonna line up with what part of your day. It's like, oh, crap, I got a three o'clock um, you know, interview, and that's after phase two ends. What am I gonna do about my floral notes being gone? Yeah? So we love to hear from you guys, smelly thoughts

or otherwise. So send us an email at science Stuff at how stuff woraks dot com, or connect with us on Facebook. Yeah, we're on there as stuff in the Science Lab. Also find us on Twitter as lab stuff and y hey, and shoot us some jokes, you know, give us some sort of nice cheesy science joke, include your you know your name and where you're from, and we will try and throw it up there at the start of the podcast. It's good, all right, that's all

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