Ever wonder why it’s so difficult to describe what you are smelling? Well it seems that characterizing fragrances and how they affect the sense of smell has been a challenge for olfactory chemists and perfume producers for years. In fact, in recent years, scientists have argued about the very nature of our sense of smell.
According to a paper published last year in Science magazine by Rockefeller University researchers (www.sciencemag.org; 21 March 2014) the human nose can detect trillions of smells. However, researchers from Caltech as well as Arizona State University published a rebuttal article in eLife (lens.elifesciences.org/08127/index.htm) asserting this isn’t necessarily true as the molecular make-up of different smells combined with individual people’s personal tastes can cloud the actual number of smells people can detect. For example, think of a color wheel. You might be able to recognize the color red as plain red. However, what elements go into creating the color red? Is red a definite primary? There can be many hints or notes of different colors that a person identifies with.
Many experts might use a mass spectrometry analytical chemistry technique to analyze the molecular make-up of elements sampled from solids, liquids, and gas compounds. Another method adopted by many perfumeries in the 1970’s is called “Headspace technology: A method pioneered in the 1970s of capturing scent molecules and reconstructing their smell for perfumes.” (https://intothegloss.com/2014/07/perfume-fragrance-definition/)
Obviously, characterizing scents, aromas, and odors is a very scientific, very difficult task. But the essence of smell is also subjective. Every individual is different and has a different chemical and physical make-up. This “subjectivity” may help or hinder how you characterize a particular smell.
We are going to do our best to break down some basic concepts to help you understand “odor profiling” and how to verbalize what you perceive.
First, understand that our sense of smell is related to our sense of taste. It is said our taste buds can stimulate five different sensations: sweet, bitter, sour, salty and umami (a Japanese word describing a savory taste). So it is often relevant to use these terms in describing smell.
In addition, the following 10 different categories of aroma are often used:
-Fragrant (e.g. florals and perfumes)
-Fruity (all non-citrus fruits)
-Citrus (e.g. lemon, lime, orange)
-Woody and resinous (e.g. pine or fresh cut grass)
-Chemical (e.g. ammonia, bleach)
-Sweet (e.g. chocolate, vanilla, caramel)
-Minty and peppermint (e.g. eucalyptus and camphor)
-Toasted and nutty (e.g. popcorn, peanut butter, almonds)
-Pungent (e.g. blue cheese, cigar smoke)
-Decayed (e.g. rotting meat, sour milk).”
But we can’t rely simply on these categories without attempting to pair descriptions with other common aromas. For example, a volcano may smell slightly of “stinky, rotten eggs” while an ocean may smell “wet, salty and fishy.” Also, there are some instances where it is difficult, if not impossible, to describe a smell using other common aromas. For example, what does a “rose” smell like? You would probably say “a rose.”