The Science Behind Perfumes

Fragrances are almost as old as civilization itself. The oldest evidence of perfume-making dates to the Bronze Age, nearly 4,000 years ago. Ancient Egyptians distilled botanical fragrances like attar and lily not only to smell better but as a sign of social status. Most historical documentation on perfume reports on the life of the rich and perfume

Over time, perfume has grown to become more than a status symbol and perfume-making has evolved from basic distillations of plants and essential oils available only to few into a booming industry. With

perfumes being so embedded in our daily routine, it does make one wonder about the wonderful science that goes behind this process. 

Picking Up Scents With Our Nose

As opposed to what was originally thought by scientists, humans actually have an incredible sense of smell, with the ability to discern a wide variety of scents. We have about 50 million scent receptors that work together to collect scent molecules when we inhale and the molecules are absorbed by a thin membrane in the nasal cavity.  

Small hairlike protrusions in the nose, called cilia, then send the appropriate signals to one of the four areas of the brain that process and manage olfactory inputs. The ability to perceive the scent itself arises from the frontal cortex of the brain. The amygdala and hypothalamus are responsible for the physical and emotional responses we have to certain smells. In essence, our noses are merely a conduit with our brain creating these responses. Hence, it really is no surprise that the mere scent of pine can summon memories of a lovely Christmas season. 

The human nose can detect more than 1 trillion individual odours. Our olfactory sense (sense of smell) is believed to be our oldest evolved sense. Neuroscience helps to back this up with evidence of smell and memory being so closely linked because of the brain’s anatomy.

How Do Perfumes Work?

If you are wondering how perfumes work, most perfumes are engineered to have a three-part smell, which unfolds after you apply it to your skin. It unfolds in the form of notes, which is perfume jargon for the individual smell. Notes in perfumery are descriptors of scents that can be sensed upon the application of a perfume. These notes are carefully created with an understanding of the evaporation process and intended use of the perfume or fragrance.

Within the first 15 minutes of application, you will be able to smell the top notes. They are the first to evaporate off your skin. After about 3 to 4 hours, the heart notes appear. The scent of this middle note compound is usually more smooth and rounded. These notes are the driving force of the fragrance and evaporate more slowly from your skin. Due to its longer ‘hang-time”, the heart notes are probably what stays with you when you smell it. For example, the flowery smell of floral perfume. 

The base notes are the scents that appear close to the disappearance of the middle notes. They stick stubbornly to your skin and bring depth and solidity. They are usually perceived within 5 to 8 hours of application. Common chemicals that go into the base include musky, watery, mossy and woody ones. 

How Does Perfume Interact with Our Skin? 

Ever wondered why a certain perfume you love doesn’t appear to love you back? Chemical reactions can morph the smell of the perfume; hence it can smell differently on different people. When perfume is sprayed on the skin, there are several factors that affect its fragrance. The pH balance of the skin differs slightly, which can change the way a scent smells. Your diet, the acidity of your skin fats, and your hormone balance also affect the aroma. These factors will either strengthen or weaken the different notes of a perfume. 

Most perfumes are made with ingredients that are attracted to oil. If you have oily skin, it will hold top notes for longer. It can also exaggerate certain elements in the perfume. Your everyday products such as soap, body lotion and shower gel also influence the way a perfume smells on you. 

To keep a perfume’s original scent, apply it to fabrics. Since it contains your body heat and personal scent, the perfume can mix well with it. And it does so without skin fats influencing the smell. However, be careful not to spray perfume on silk, suede and leather. Using a shower gel designed for sensitive skin will also help keep your pH in check and in turn, work to not alter the smell of the perfume when it touches your skin. 

Whatever the reason is for which you are wearing perfume, be it to feel confident or stand out, the science behind how you smell is fascinating. It leaves little to the imagination as to why a fragrance can create such a powerful impact in your life.