Sense of Smell – The Master of Decepting the Senses
In the context of the coffee experience increasingly being elevated to a sensory journey, the sense of smell – one of the most primitive senses of mankind – is playing a more important role than ever. We drink coffee not only with our mouths, but also with our memories, emotions and olfactory reflexes that have been accumulated throughout our lives. When passing a bakery, the aroma urges us to stop.
When entering a coffee shop, even if we initially do not intend to order a drink, the aroma of freshly ground coffee is sometimes enough to change our mind. The sense of smell becomes the “pen” that writes the script of our experiences, shaping consumer decisions that we sometimes don’t even notice. Scents alter how memories are processed in the brain, directly influencing our emotions and sensory experiences.
The silent persuasive power of scent in everyday life
Not only humans, animals in nature also rely on the sense of smell to survive and find food . For example, dogs can smell from hundreds of meters away, and birds can detect food or enemies thanks to this sensitive ability. In humans, the sense of smell also plays an important psychological role: people who live far from home will feel warm and safe when returning home thanks to familiar smells. Couples also often close their eyes to feel the breath, a form of close interaction based on scent.
In modern life, the sense of smell has become a “master of deceiving the senses” : we often rely on scent to judge surrounding objects without seeing them directly. For example, smelling an apple will create the feeling that the apple is in front of us, even though in reality it is just a fragrance. Cosmetics and personal care brands have fully exploited this phenomenon: coconut-scented shampoo reminds users of the beach, vacation, creating a feeling of instant relaxation; newly launched perfumes can evoke feelings of confidence, romance or refreshment depending on the scent.
Smell, memory and the brain’s ability to imagine
Every person is born with a unique store of olfactory memories . From the smell of bleach on your hair after a summer swim, to the smell of leaves after a rainstorm, or the smell of your grandmother’s cooking, all are recorded by the brain. These scents not only evoke memories but also influence current feelings and behaviors.
A 2024 study published at Harvard University found that scents can trigger memories and emotions five times stronger than visual images . Therefore, the scent experience in retail spaces, cafes or restaurants is not just a marketing gimmick but is also based on science – helping customers form a deep emotional connection with the product.
Conditions for the formation of the sense of smell and the sophisticated mechanism of operation of the sense of smell
The sense of smell works based on a complex system consisting of:
- Volatile aroma molecules
- Airborne transmission
- Olfactory organs (receptor cells)
- Olfactory nerve and processing centers
- Olfactory memory store in the brain
The process goes like this: odor molecules are released into the air, enter the nose, pass through the mucus layer and come into contact with olfactory cells. The signal is then transmitted through the olfactory nerve to the brain, where it is combined with previous odor memories to determine the final perception of the scent.
Smell and hearing are both senses that help us perceive from a distance, but they are different in nature: sound is wave energy, while smell is based on actual matter – volatile odor molecules . The ability to detect scents can be affected by:
- Concentration and volatility of odor molecules
- Wind speed and humidity
- Nasal conditions, rhinitis or colds
- Level of fatigue or stress
For example, when squeezing an orange, the strong evaporation of essential oils helps the scent spread far, while pure water is almost impossible to detect by smell. If you have a cold, the mucus layer thickens, reducing the ability to detect smell – this is why many people say “losing the sense of smell means losing the taste”.
Olfactory perception in coffee cupping: layers of aroma and sensory mechanisms
In coffee cupping, the process of smell recognition takes place through three main stages:
- Dry aroma – from ground coffee after roasting, mainly organic compounds released with CO2 gas. This is the first step to help identify floral, fruity and grassy aromas.
- Wet notes – when boiling water is poured into coffee grounds, aromas rise from the surface of the water. These aromas often include fruity, herbal, and nutty notes.
- Aromatics retronasal – when you sip coffee, the molecules travel back up your nose, creating a final perception of caramel, chocolate, or nutty flavors.
The sense of smell can be trained. Long-term, intensive practitioners will develop a rich olfactory memory , especially with extremely light, where floral and fruity notes are evident: roasted almonds with peanuts, orange blossom with jasmine, or identifying the origin and processing method of a coffee in just a few seconds of smell.
The role of olfactory training and its effect on taste
On average, each person can distinguish between 2,000 and 4,000 different types of smells . With practice, the ability to recognize and remember smells can surpass even innate sensitivity. Coffee experts often use the Le Nez du Café set of 36 scent bottles, divided into 4 main groups:
- Yeast group: floral, fruity, herbal, volatile scent
- Caramel group: hazelnut, caramel, chocolate scent
- Dry distillation group: resinous, spicy, charcoal smell
- Flaw group: strange smells, used to practice the ability to recognize defects
Through practice, the taster can determine the origin, the preparation method through the flavor wheel, or even just by smell, thereby enhancing the tasting experience.”
Additionally, the sense of smell largely determines the sense of taste . According to research, 75-95% of what we perceive as “taste” is actually the scent from the olfactory sense . If you hold your nose when drinking wet-processed Yirgacheffe coffee, the floral experience will disappear, leaving only a simple sweet and sour sensation.
Olfaction in modern life: experience, emotion and memory
The sense of smell not only determines the culinary experience , but also affects the perception of space, people and personal memories . A pleasant scent will help the experience positively, while an unpleasant smell can cause a negative reaction. In modern cafes, the space is designed to optimize airflow and neutral materials to enhance the coffee aroma experience , from the roasting of beans, the brewing method to the music that supports concentration.
Experts emphasize: just by observing and paying attention to the scents around , each person can expand their sensory experience, enhancing the sophistication in enjoying food, drinks and living space. The sense of smell, from a little-noticed sense, has now become a powerful tool in the modern human experience , combining science, art and personal experience.
(*) Image source collected
