Fragrance is a term that refers to any substance or mixture of substances that conveys a pleasant smell, whether from natural sources such as flowers, herbs or foods, or synthetically manufactured fragrances found in scented household products. The word is closely related to the terms perfume, cologne and redolence, which also refer to an enjoyable odor.
The art of creating and mixing odoriferous substances to produce a perfume or cologne has been practiced for thousands of years. In fact, references to the creation of perfume have been found in ancient Chinese texts, Hindu texts and Egyptian texts, and there are also mentions of odoriferous substances in the Bible.
Perfumes are liquid mixtures that emit a distinct odour when applied to the skin. They are made from fragrant essential oils derived from plants and spices or synthetic aromatic compounds. These are combined with other ingredients such as solvents, fixatives, stabilizers and preservatives to create a finished product. The main groups of perfumes are parfum, eau de toilette, eau de cologne, and aftershave. The differences between these are mainly the concentration of the fragrance chemicals, with parfum having the highest concentration.
A perfume’s composition is a combination of various odorous substances that diffuse at different times and can be broken down into three categories: top notes, middle notes and base notes. The top notes are the initial odours that appear when the perfume is applied or opened, and they evaporate quickly. The middle notes are the scents that emerge just prior to the dissipation of the top note, and they form the heart of a perfume. The base notes are the most persistent odours, and they last for several hours after the middle note has disappeared.
Creating a fine perfume requires an understanding of the interplay between these different components, as well as the ability to combine them to produce the desired effect. During the process of developing a new scent, many creative decisions must be made in order to achieve the desired result. For this reason, creating a great fragrance is considered to be both an art and science.
The chemistry of fragrance is complex, with each raw material having its own unique characteristics that need to be balanced. For example, the odour of a flower can vary depending on when and where it is harvested as well as its chemical composition. The quality of a raw material can also vary by supplier. This can be due to the different methods used in growing, harvesting and extracting a particular scent, or it could be the result of adulteration of the actual raw material.
Some of the most commonly used odour-producing compounds are derived from natural sources such as flowers, herbs and fruits. These are typically extracted by steam, water or solvent distillation. Other fragrance chemicals are synthesized, and these often have advantages over natural scents. For example, some synthetics are less expensive than the natural raw materials they emulate, and they can have a more consistent smell when compared to naturals. This makes them a popular alternative in modern perfumes.