About the senses taste and smell. Why did a woman have to correct misinformation after 30 years, and why can you smell better with a low blood-alcohol level as explored in “The Senses Behind Tasting”
In a Glass
The tongue perceives taste, the five basic tastes are sweet, salty, sour, bitter, and umami. Olfactory cells in the nasal mucosa are responsible for the sense of smell. Taste and smell are not the same thing.
But what exactly are they? They are certainly important.
And how they function is explained further down.
The Taste
The Tongue
The tongue is the center of taste. On this muscle in our mouth, there are several small bumps called papillae. Located on these papillae are microscopic taste buds, which allow us to perceive taste. There are three types of papillae primarily responsible for taste reception: circumvallate papillae, foliate papillae, and fungiform papillae.
The older you get, the fewer taste buds you have. The papillae remain, but the taste buds die off.
The Tongue Map is wrong
So, the Tongue is the place where the taste happens and there is a myth or, to be more precise, a piece of misinformation that has stubbornly persisted for over 50 years. The Tongue Map indicates the locations on the tongue where the individual tastes are perceived and that is wrong.
In 1901 the German physiologist D. P. Hänig established that some parts of the tongue are slightly more sensitive for particular tastes.
The mistake then happened 41 years later. When Harvard psychologist Edwin Boring translated the data wrong in a textbook. His graphical representation made small differences in sensitivity appear erroneously as exclusive zones, which gave rise to a myth that persisted for decades.
Virginia B. Collings refuted in her work “Human taste response as a function of locus of stimulation on the tongue and soft palate” in 1974 the tongue Map.
She demonstrated that the taste receptors for all five basic tastes: sweet, salty, sour, bitter, and umami, are distributed across the entire surface of the tongue, palate, and throat. While there are minor variations in sensitivity along the edges, there are no isolated zones.
What do we Taste?
On the tongue are millions of taste papillae and taste buds to perceive the Taste. The receptors send signals to the brain, and the brain then evaluates those signals.
The five Tastes:
Sweet
The taste of sweetness signals the presence of readily available carbohydrates and energy, such as in the form of sugar or fruit and alerts the body to the location of safe, calorie-rich food.
Salty
Salt indicates the presence of essential minerals. It regulates the body’s water balance, blood pressure, and nerve functions.
Sour
A warning sign is the taste “sour” should admonish of unripe fruits or spoiled food. Already small amounts of acidity stimulate salivation and promotes digestion.
Bitter
The taste of bitterness is an ancient warning signal intended to protect against toxins. Many poisonous plants taste bitter.
Umami
The word for pleasant taste in Japanese. It points to the presence of protein and amino acids. It signals that a food contains protein and ensures a long-lasting feeling of satiety.
Not a Taste but we feel it?
The tongue perceives not only the five basic tastes but also chemosensory stimuli. With their millions of sensory cells, the papillae also perceive texture, temperature, and pungency. Capsaicin, for example, creates a sensation of heat; carbonation produces a tingling feeling; tannins cause a sensation of dryness; and menthol provides a cooling effect.
The Smell
The Nose
Unlike the tongue, which can distinguish only five basic tastes, the nose is responsible for the vast majority of what we perceive as flavor. It is estimated that olfactory impressions account for approximately 75 to 95 percent of what we commonly refer to as “taste.”
How it Works
When we eat or drink, aroma compounds reach our olfactory receptors, located in the mucous membrane in the upper part of the nasal cavity, via two distinct pathways. The first is the orthonasal route: aromas travel directly through the nostrils to the receptors, much like what happens when we smell something. The second is the retronasal route: here, aromas reach the receptors via the throat (pharynx) while we are chewing or swallowing. This is precisely why a food or drink tastes different when consumed compared to when it is merely smelled.
Humans possess approximately 10 to 30 million olfactory cells within the olfactory mucosa. These cells have a lifespan of about 4 to 8 weeks and are continuously renewed. Typically, each scent compound activates a combination of several different receptors, enabling humans to distinguish between tens of thousands of different odors.
Smell and Memory
Of all the senses, the sense of smell is the most directly connected to the limbic system, the part of the brain responsible for memories and emotions. This is why a specific aroma can instantly transport us back to a particular moment or place. It also explains why descriptions of aromas are often highly personal and associative: one person might perceive “banana,” while another associates the scent with “nail polish,” even though both may be describing the exact same ester. This is also why certain smells become inseparable from specific tastes, vanilla being a prime example.
The Nose and Spirits
When you smell a spirit, volatile aromatic compounds evaporate from the surface of the liquid and travel directly to your olfactory receptors. This is why the shape of the glass plays such a crucial role: a narrower opening concentrates the aromas, whereas a wider glass allows them to dissipate more easily.
The alcohol itself is also perceived by the nose; if the alcohol content is high, it can mask more subtle aromas. For this reason, you shouldn’t thrust your nose too deeply into the glass right away, so as not to overwhelm your senses. Furthermore, when dealing with cask-strength spirits, adding a few drops of water can help “open up” their flavor profile. The water reduces the evaporation of the alcohol, allowing the more delicate aromatic compounds to reach the nose more effectively.
The olfactory system is not yet fully understood. However, here is an interesting funfact from the scientific community: research conducted at the Weizmann Institute in Rehovot has shown that olfactory performance is actually better when a person has a low level of alcohol in their system compared to when they are completely sober. The exact reason for this remains unclear. Nevertheless, previous studies have suggested that a region of the human brain responsible for the sense of smell is subject to constant inhibition. It is possible that alcohol suppresses this function, thereby lifting the inhibition and enhancing one’s ability to smell.
How to train your Senses?
There are different ways to train your senses, from blind tastings to dedicated olfactory exercises.
Olfactory Training
For this, you can select four different scents, ideally essential oils specifically intended for olfactory training. Such oils are often found in aroma kits or “Le Nez du Vin”. Each scent should represent a distinct category, for example
– Floral: Rose
– Fruity: Pear
– Spicy: Cinnamon
– Herbal/Botanical: Pine needle
Hold each scent 3–5 cm away from your nostril. A distance of less than 3 cm may irritate or overwhelm the olfactory receptors, while a distance greater than 5 cm will be too faint to provide sufficient stimulation.
The training should be performed while in a relaxed yet upright position, either sitting or standing. Hold each scent in front of your nose and inhale for 15–20 seconds. While smelling, it is helpful to focus intently on the item and visualize it; this strengthens the cognitive association with the scent. Afterward, take a 30-second break before moving on to the next scent.
Final Thoughts
We do it constantly, we do it all the time. Yet, unfortunately, we often do it without much conscious awareness. While the tongue and the nose work hand in hand, we still need to learn to distinguish between taste and smell. Understanding why we perceive certain flavors the way we do is helpful when creating food and drinks. Furthermore, the close connection between the sense of smell and the limbic system allows us to relive past experiences and the emotions associated with them.
