Barry C Smith is a Professor of Philosophy and Director of the Institute of Philosophy in the School of Advanced Study, University of London, where he co-directs the Centre for the Study of the Senses. He has written mostly on the philosophy of mind and language, on the topics of self knowledge and our knowledge of language. He works with psychologists, neurologists and neuroscientists on flavour perception and is now the co-organiser of an international research project on the Nature of Taste, jointly run by the University of London and NYU. He has published a collection called Questions of Taste – the philosophy of wine (2007) and was the writer and presenter of the BBC World Service radio series, The Mysteries of the Brain.
Tasting is deceptively simple. We pop something in our mouths, sip or chew it and instantly we seem to know how it tastes and whether we like it. But it’s surprising how little we know about tasting. For a start, we get very little of what we call taste from the tongue. The best way to illustrate this is:
Going from sweet or sour only to the ‘taste’ of strawberry, or orange or coconut, when you stop pinching your nose, lets you know how much smell contributes to what we taste. The tongue only has receptors for sweet, sour, bitter, salt, savoury and metallic – it has no receptors for strawberry, cherry, mint, etc. These are contributed by olfaction and the resulting combination of taste and smell is called flavor. What’s more, our tongues are different. Some people have very densely packed papillae making them more sensitive to bitter flavours. These are the so-called super-tasters, and we can tell who is a taster, a non-taster or a super-taster by their reactions to stops of paper that have been soaked in phenol-thio-carbamide, or PTC.
Many things contribute to the flavours we experience when tasting, including touch. Temperature makes a difference. Some people find warmth on the tongue sweet, and cold salty or sour. These are thermal tasters. But for all of us, when a liquid, like coffee is cooler, it tastes more bitter.
In addition to touch, taste and smell, there is a contribution from the trigeminal nerve (or facial nerve) that serves the eyes, the nose and the jaw. This nerve is irritated by spices, making mustard taste hot and peppermint taste cool, even though there is no change in temperature in the mouth. Carbonation, too, affects the trigeminal nerve and accentuates sourness.
All these factors affect our individual experience of wine: the temperature of a wine, the carbonation in the bubbles of Champagne. And perhaps, through technology, restaurants may in the future be able to cater to these differences and give the diner a better experience. Normally, when we drink wines, we do the hardest thing: tasting a single glass of wine. A much easier exercise, which we explored together, is comparative tasting:. By comparing two glasses of wine, deciding which one you prefer, and why, you learn more about each wine, and improve your skills as a taster.
How could restaurants enhance people’s experience of wines, offer them choices and increase their knowledge? Perhaps diners can be presented with small viols of different wines, or the same wine at different temperatures and decide how they would like to drink their chosen wine. No longer would diners be asked to taste the bottle they ordered. By new trying new tasting techniques people would learn more about wines and about themselves.