Fragrance notes – how a scent is constructed

When associated with fragrance, notes are descriptors of scents that can be sensed upon the application or delivery of a particular fragrance to i.e. a room. Fragrance notes are separated into three categories;

Top/head notes

Middle/heart notes 

Base notes

These three categories represent the groups of scents. They can be sensed with respect to the time after the delivery of a fragrance (or in perfumery, the time when the perfume was applied). The creation of fine fragrance and the science of perfumery is one that is very hard to replicate without detailed knowledge of how perfumes are created and just how notes blend together.

These notes are carefully created with an understanding of the evaporation process and intended use of the perfume or fragrance.

The presence of one note may alter the perception of another – for instance, the presence of certain base or heart (middle) notes will change the scent perceived when the top notes are strongest. The same for the scent of base notes in the “dry-down” – these will often be altered depending on the smells of the heart notes.

Top notes

Top notes are otherwise called the head notes. These notes are apparent or detected immediately upon application of a perfume or delivery of fragrance to a room.

The top fragrance notes consist of small, light molecules that evaporate quickly. These notes are important as they form a person’s initial impression of a fragrance and thus are very important in the selling of the product – it’s important not to ‘top load’ a fragrance. Scents that are associated with top notes are usually described as “fresh”, “assertive” or “sharp”. Think of a Bergamot, Citrus, Lemon scent. The compounds that contribute to top notes are strong in scent and evaporate quickly. They are strong, pack a punch and provide an instant impact however need additional notes to support their longevity.

Although not as prominent or obvious to the nose, the heart and base-notes actually contribute much to the scent in the top notes – much more than a person exposed to a scent would think.

Middle notes

They are also called the “heart notes”.

The middle fragrance notes are scents that come to the fruition just before the top notes disperse. The middle note compounds form the “heart” or main body of a perfume and emerge in the middle of the perfume’s dispersion process. Middle notes mainly serve to mask the often unpleasant initial impression of the base notes. Though these become more pleasant with time. The scent of a middle note compound is usually more smooth and “rounded”. When applied as a perfume, scents from this note class disappear anywhere from twenty minutes to one hour after the application. When dispersed in the air, the middle notes are the driving force of the fragrance, allowing for longer ‘hang-time’ than other notes.

Lavender is a typical middle note.

Base notes

The base notes are the scents that appear close to the disappearance of the middle notes. The base and middle notes together are the main theme of a fragrance.

Base notes bring depth and solidity much like any strong foundation or, base. Compounds of this note category are often the ‘preservatives’ used to hold and boost the strength of the lighter top and middle notes. Consisting of larger, heavy molecules that evaporate slowly, compounds of base note scents are typically rich and “deep”. When applied as a perfume, they are usually not perceived until 30 minutes after the application of the fragrance. If applied in a spray or dispenser, these notes would be the ‘final’ fragrance recognized in the air.

Some base notes can still be detectable after twenty-four hours, after any application, particularly musk notes. Much like in music, the different fragrance notes each play a part in building the structure of a scent. Without each fragrance note, a scent would smell very different indeed.

Explore Scent Marketing to find out how scent can help brands and businesses engage with their customers and target audiences in new ways.