Ludwig Wittgenstein Archives

The Biology, Psychology, and Philosophy of Wine Tasting

Kandinsky, *Composition VII* (1913). The mind at work.

By Dr Neel Burton — Psychiatrist, philosopher, and wine writer; Fellow of Green Templeton College, University of Oxford; author of over twenty books.

What happens when a novice and an expert taste wine? Is it simply a matter of the wine impressing itself onto their senses? Or does the expert enjoy a different wine?

To answer this question, we need to begin with the biology of taste.

The Biology of Wine Tasting

Our sense of taste arises from specialised sensory cells in taste buds on the tongue, hard and soft palate, and pharynx. There are around five thousand taste buds in the mouth, each with fifty to one hundred of these sensory cells, or chemoreceptors. Together, these chemoreceptors enable us to distinguish five basic or fundamental tastes: alkaloids and other compounds as bitterness, sugars as sweetness, salts as saltiness, acids as sourness, and amino acids as umami or savouriness. Although some parts of the tongue are more sensitive to certain tastes than others, the ‘tongue map’ that divides the tongue into discrete tasting areas very much overstates the case.

Chemical sense of taste is supported by the physical and chemical sensation of the liquid in the mouth, or mouthfeel. The physical sense of touch, which is responsive to dissolved particles as small as three microns, transmits the texture and temperature of the wine through specialised mechanoreceptors and thermoreceptors. The prickle of dissolved carbon dioxide is conveyed by chemesthesis, the same sense or sensibility by which chemical irritants such as chilli or mustard register their fieriness—not through taste, but through provocation.

Sense of smell, or olfaction—which is even more important—is triggered by airborne chemicals acting on olfactory receptors on the tiny hair-like cilia of olfactory receptor neurons in the nasal epithelium. The axons of these olfactory receptor neurons form the olfactory nerve (cranial nerve I), which courses up through the sieve-like cribriform plate of the skull to synapse in the olfactory bulb of the brain. There are around four hundred types of olfactory receptor, which, through a form of combinatorial processing, are capable of discerning several thousand aromas. Sensitivity to aromas can differ significantly, both from one aroma to another and from one individual to the next, with some aromas detectable in concentrations one hundred million times smaller than others.

The olfactory apparatus can be stimulated orthonasally, through the nostrils, or retronasally, from within the mouth and pharynx. Much ‘tasting’ actually takes place retronasally, which is why a runny nose can leave our food and wine tasting of cardboard.

What we call ‘taste’ is therefore much more than taste: it is also touch, temperature, chemesthesis, and, above all, olfaction. But this still leaves out the most important organ of all: the brain.

The Psychology of Wine Tasting

The ‘flavour’ of a wine is an integrated interpretation by the brain of all the various sensory stimuli detailed above. Upon tasting the wine, the brain experiences a sensory overload, whence the difficulty in picking out individual aromas and flavours. To ease its task, it relies heavily on preconceptions (including injurious ones, i.e. prejudices), context, and memory to inform its interpretation of the sensory stimuli.

The effect of expectation is so strong that, if a white wine with an aroma of lemons and apples is dyed red with food colourings, most people will describe red berry aromas; and if an ordinary table wine is served in a bottle labelled ‘Grand Cru’, most people will praise it as ‘balanced’, ‘complex’, and such-like.

The olfactory bulb is closely connected to the limbic system, an area of the brain linked with emotions and memories. Smells and tastes can trigger strong emotions and vivid memories that bias our perception of the wine. Conversely, our emotional state affects our appreciation of sensory stimuli, which explains why wine tastes better in good company or why champagne has it easy.

Blind tasting can help us overcome all these biases, first, by removing a number of their sources, and, second, by inviting us to focus on the wine itself. Paradoxically, by depriving ourselves of cues—grape variety, region, vintage, price, reputation, memories associated with the wine—we become a lot more attentive to the information that remains.

The Philosophy of Wine Tasting

In engaging with a wine, blind tasters activate not only the limbic system, but also areas of the brain responsible for cognition, which is a conscious, higher-order function. This process can be assisted and developed by writing tasting notes that seek to accurately describe the sensations produced by the wine. Given the limitations of language in accurately describing our sensations, this, like writing poetry, is no mean feat.

Nonetheless, language is by far the best tool at our disposal for communicating our experiences to others and, indeed, to ourselves. The practice of consciously describing the sensations produced by wine trains the mind and, over time, makes it much easier to taste and think about taste. As Wittgenstein famously remarked, ‘The limits of my language are the limits of my world.’

But does the language of wine merely enable us to describe what we taste, or does it enable us to taste more in the first place? Learning to taste involves learning what to attend to, how to discriminate, how to compare, and how to remember. What was once an undifferentiated sensation gradually resolves into parts, patterns, and relationships. Language does not merely label the world: often it helps us to notice it.

Although some people do have a higher density of taste buds, this does not necessarily make them better wine tasters. To use a computing analogy, tasting is not so much a function of the hardware (the sensory apparatus) as it is of the software (the mind or brain). That’s why I often say we taste far more with our brains than with our mouth and nose. Regardless of the sensitivity of their tasting apparatus, untutored tasters struggle to ‘get their head round’ more complex wines, and, as a result, derive greater enjoyment from simpler wines.

Just as an untrained ear can struggle with complex music, an untutored palate can struggle with complex wine. To the beginner, it can seem as though the more experienced tasters are making it up. But with enough experience and training, almost anyone can turn into a wine expert.

Think again of Kandinsky’s Composition VII. To an untutored eye, it can seem like a bewildering profusion of colours and forms. With sustained attention, relationships, rhythms, tensions, and depths begin to emerge. The painting has not changed.

If a novice comes to dinner, open something you can both enjoy. But keep your best Burgundy for experienced tasters such as me.