For a long time, nature has been spritzing itself with eau de this-is-my-territory-not-yours and guess-what-I’m-in-heat cologne spray. You have to ask who made the jump from grinding the secretions from a civet cat’s anal gland into a perfume bottle, but someone did. Someone else has dumped the scent pods of male musk deer into a bottle of perfume. That was the root of the original musk. In went the material from beaver urine and smell sacs, as well as sperm whale intestines.
While they were common in early perfumes, real civet, musk, castoreum, or ambergris are now rarely used in fragrances. It’s now cheaper and simpler to create fakes in the lab, so most low-cost modern perfumes do so.
Modern perfumes have evolved to include fouler-smelling chemicals. Take, for example, Eau de Stilton, a Stilton Cheesemakers Association commission designed to bring more consumers on to the food [source: Discover]. You might say the Stilton scent was a joke, but actual perfumes sometimes have stench notes as a kind of circus act by the artist. The rotten note in Sécrétions Magnifiques, a fine fragrance, was exciting and intellectual, according to Luca Turin, a biophysicist and well-known perfume writer [source: Turin and Sanchez].
Perfume, in the broadest sense, is any liquid that you carry and that smells. There are no prerequisites for it to smell good. Clearly, the understanding of a perfume is shaped not just by what is in the bottle, but also by what is in your mind. Keep reading to find out what’s in the bottle.
The solvent in liquid perfume is a blend of alcohol, water, and molecules that evaporates at room temperature. “A scent is simply a molecule that’s light enough to float in the air, but not every molecule that’s light enough to float in the air has a smell — carbon monoxide, for example,” says Avery Gilbert, a sensory psychologist who’s worked with the fragrance industry. The smell is generated as cells in your nose detect evaporating molecules and relay electrical signals to your brain, resulting in a perception. Read How Scent Works to find out just how we smell.
If you’ve read the French phrases on your perfume bottle, you’re already aware that perfumes come with a variety of strengths. Perfume oils are the most abundant. They have been removed from a vine, herb, or fruit by crushing, steaming, or chemical separation [source: Sell]. Fragrance compounds are dissolved in 98 percent alcohol and 2% water in perfume oil. Anything that is perfume oil that has been mixed with alcohol. From most concentrated to least concentrated, parfum contains at least 25% perfume oil; eau de parfum contains 15 to 18%; eau de toilette contains 10%; and eaux de cologne and body spray contain less [source: Turin and Sanchez].
Perfumes are also divided into fragrance families in the perfume community. The categories exist and the words are used by commentators and designers. There are no universally agreed-upon groupings, nor are there any rules for categorization other than common sense and a perfume belonging whether it smells like the last perfume in the division. Here are a few classifications you might have come across:
- Floral: smells like flowers
- Fruity: smells like fruit, including citrus
- Green: fresh grass or leaves
- Herbaceous: like any variety of herbs
- Woody: like different types of wood
- Amber: like tree resin
- Animalic: bodily smells
- Musk: like a substance made by the musk deer
- Oriental: amber and spice
Sometimes perfumes are categorized according to the structure of one of its fragrant molecules:
- Aldehydic: fatty but makes other smells radiate
- Lactonic: creamy and fruity
- Phenolic: smells like tar
Tired of these subjective categories? There are no ambiguities in the chemistry of perfume, except in the secret ingredients, of course. Read on to learn basic perfume chemistry.
How Perfume Works
Why is perfume too watered down? It’s not as if factories are cheap. The real reason is purely aesthetic: A lot of alcohol spreads out the smells, making them easier to discern. You’d find a muddle of smells in a perfume spray. It would be like watching an orchestra play all of the notes of a symphony all at once if you smelled it. You might note that you’re smelling something sweet, but not that it’s strawberry, jasmine, and cherry. Because of its diluted nature, the smell is good.
In fact, most perfumes are formulated to have a three-part fragrance that grows after you add it to your skin. Within the first 15 minutes of use, you can smell the top notes. These compounds evaporate first from your skin. Designers also use strange, gross, or spicy odors in this process so that they pique your curiosity but do not last long enough to offend. After 3 to 4 hours, heart notes emerge. The chemicals that create these odors evaporate more slowly from your skin. They’re most likely what you remember from the perfume; if it’s a floral perfume, flowery scents belong here. Foundation notes cling to the skin with tenacity. You will scent them 5 to 8 hours after applying them [source: Sell]. Chemicals that are musky, watery, mossy, or woody are commonly used in the foundation [source: Calkin]. The term note is simply perfume jargon for a distinct odor.
Knowing the perfumes lose their scent when they evaporate allows you to apply them with more caution. When applying the perfume, spread it evenly but do not rub it in vigorously, as the heat generated would evaporate the top notes and diminish the overall scent.
Chemical reactions may also change the appearance of your perfume on the rack. Visible light contains enough energy to break the bonds in fragrance molecules, and direct sunlight will singe your perfume in as little as a week [source: Turin and Sanchez]. By oxidation, air will also corrode the scent, which is the same mechanism that converts uncorked wine into vinegar. Using your scent at room temperature, in the dark, and in a spray bottle would keep it fresh for a long time. Then it would have a minimum shelf life of two years [source: Sell].
What about your chemistry, though? Your temperature and oiliness seem to be the most significant factors. Hot and dry skin evaporates top notes quicker than cold and oily skin. Otherwise, by the time the heart notes appear, all smells the same [source: Turin and Sanchez].
You now understand the structure and actions of your perfume. You have spread but not vigorously rubbed. Following that, we’ll look at how the fragrance industry makes the stuff.
The manufacture of perfume begins with a company’s intention to sell you a perfume. Assume Gucci needs to announce a new scent. The organization will establish a short overview. It explains who and why the perfume should cater to, as well as what the fragrance should convey to the smeller, such as “classy,” “irreverent,” or “sunrise in Thailand.” It describes the fragrance’s shapes, such as a light green spray and a white soap, which assists chemists in selecting compatible ingredients. Finally, it describes where and how long the goods will be available: in Europe and Asia for the next two years.
The brief is mailed to a number of scent houses. Fragrance houses are businesses that have two operations. They recruit perfumers, who build and write perfume recipes. Fragrance houses also hoard thousands of perfume products, including spices stored in factories, fruit and flower oils, and vials of chemicals that simulate tobacco smoke, leather, or endangered wood species. Both operations are assisted by chemists. Analytical chemists are used by scent houses to classify compounds in an unknown liquid using an analytical method known as gas chromatography mass spectrometry (GCMS). Synthetic chemists who can create such molecules are often employed by fragrance houses.
The perfumer reads the brief, remembering the scents of a Thai sunrise. She makes a list of ingredients, including lime, coconut rind, papaya, and chili pepper. She then considers sources. The perfume house’s warehouse can contain coconut rind. Whether the company does not possess the scent of fresh papaya, it will have to purchase the result of someone’s headspace initiative, which we’ll explore in a moment. Since natural chili pepper extract would sting the nose, the corporation would then need to create or purchase a chemical that smelled like chili pepper.
You may be curious how fragrance houses store their caches. They can purchase ingredients from farmers and then extract the juices by steam distillation or chemical extraction. They may even order from companies that do the legwork for them. However, since fresh and steamed papaya have different smells, they can use a technique known as headspace. A fragrance house associate will place a ripe Thai papaya in a jar and vacuum out the scent for up to eight hours [source: Sell]. The samples would be returned to the fragrance house, where a chemist would study them using GC-MS to generate a printout of the molecules in that perfume. She’d try to reproduce the perfume from scratch.