Senses Working Overtime – how we taste wine
We call it wine tasting, yet a glass of wine can engage with all our five human senses. Moreover, it uses up more of the human brain than most other behaviours. Most of us have these senses in working order, and normally we take them for granted. Other animals may have different or more powerful senses, but ours are great all-rounders. This article briefly looks at how we use them in enjoying or analysing wine. It’s also my belief that wine tasting is a skill that anyone can master, without ever resorting to super-powers.
Five detectors in search of an interpreter
Our five senses are sight, hearing, smell, touch and taste*. These, especially when in combination, enable our participation in the world around us.
Our highly sensitive sense organs collect and then transmit sensory data via various pathways to the brain. Only there can it become meaningful. Different regions of the brain decode, create and interpret a sensory picture. Our emotional and physical responses follow. In other words, we detect, then think, feel and remember, and act accordingly.
Let’s say a bottle of wine is 85% water. Another 14% of it is alcohol. That leaves only about 1% of various chemicals to define the wine’s signature. In enjoying or analysing wine, we are mostly making a fuss about that 1%!
With wine, the emotional response is often one of pleasure, but sometimes pain. If we want to share this, the brain invokes our unique language abilities in an attempt to do so. Others can then agree or disagree with what’s said.
Our sensory processes happen in real-time, all the time. It happens in milliseconds. Determining how this works is primarily down to biological research. Yet even today, many details are yet to be determined, and discoveries continue.
Neurology is a gigantic and complex subject. Hence, this necessarily short article is simplistic and superficial at best. Hopefully, it will pique your interest and encourage curiosity.
First and foremost, humans are visual beings. Sight depends on the light in visible wavelengths entering our eyes. Usually, we can see in three dimensions, follow motion, vary our focus and see the big picture and tiny detail. In the dark, we’re almost blind.
Claims vary, but most can see 1-10 million colours, while a tiny minority can see 100 million. Rarely, some can even see in ultra-violet. More commonly, some cannot distinguish between red and green.
Also, our language is crammed full of visual descriptors that we can share and communicate. We have to borrow many of these to describe our other senses, however imperfectly.
Before we ever see the wine, we’ll see a package, a label, an advert, which create desire. Once the wine is in the glass, our sight gives information about age and condition based on colour. The wine might be an old white or young red, a pretty rosé, or anywhere in between. We can also see viscosity in the glass, perhaps from alcohol or glycerine, and possibly sediment or a contaminant.
If you hide the colour in a black glass, our other senses alone cannot readily ascertain whether the wine is white or red! It suggests that we also have preconceived ideas from previous experiences that are often gained from vision. Preconceptions mean we tend to go with what we think or we know or expect, even when that conflicts with our other senses. That’s why it’s important to serve wine “blind” when judging.
Facetiously, the best part about sight is that we can see when our glass needs refilling!
Humans can hear vibrations, in a frequency range from 20-20,000 Hz at best, and from a whisper to a scream. Hearing seems of limited use in a wine context – but surely you’ve listened to a glass of fizz? If you haven’t cocked your ear to the sound of effervescence, then I recommend you do, at least privately. How loud is it, at what frequency and for what duration?
And while on the subject, who hasn’t enjoyed the loud popping of a cork? Or the muted glug from a bottle? Perhaps there’s a sound made when swirling the wine in the glass, or when swallowing. All these are part of the fun, at least.
But what about distracting loud noises or speech? Those can undoubtedly prevent concentration. Conversely, soft music might help us relax and enjoy a wine experience more fully. What restaurant doesn’t employ this tactic?
We associate touch with our skin, which is our largest sense organ. Unless you bathe in wine (see my forthcoming article on that subject, hedonists), then touch comes into play when the wine is in the mouth. There is tactile physical experience from the mucous membranes on the inside of the mouth, the lips and tongue. Even the teeth might be involved, painfully so if the wine is icy cold.
Touch allows us to perceive volume, weight, texture/mouthfeel, persistence and temperature. All of these give clues to wine quality as well as pleasure.
The most important senses for wine are smell and taste. These two senses often work together.
Let’s begin with wine chemistry. Wine is a liquid with many properties that we mostly detect through smell and taste. Every wine has a different chemical cocktail dissolved in a solution of water and alcohol. Each of these chemicals has different properties and occur in varying and often tiny amounts.
Some of these chemicals are volatile and start to react on contact with air. Some will oxidise, others will evaporate and become odourants. As a wine’s temperature increases, more of these odourants form. There is a Goldilocks temperature zone, as below 6 °C, evaporation is so low that there isn’t much aroma and flavour to detect. Once over 20 °C, many of the chemical compounds will have boiled off, while even the alcohol will start to evaporate. This is why wine serving temperature is important.
Each of these odourants has a unique aroma message at a specific temperature, even if they are only present in minute quantities. Different grape varieties have varying amounts of chemical compounds and vinification, and maturation can add even more. Humans are good at detecting them, primarily by their sense of smell, involving inhaling them through the nose and the mouth.
The human nose may be less sensitive than those of other familiar animals, yet it’s still an incredible sense. Furthermore, smell contributes 90% of taste. It’s easily shown when you have a cold; it’s then hard to smell any difference between a grated apple and a grated onion! Fortunately, such anosmia is, while miserable, usually temporary.
Our noses are also highly sensitive. For example, we can start to detect some chemicals in tiny concentrations of only a few parts per million, billion, or even trillion! For instance, Trimethyl Amine (an unpleasant fishy odour found in human sweat) is detectable at 0.21 parts per billion! Hydrogen Sulphide (rotten eggs) comes in at 0.47 ppb. TCA (the chemical involved with corked wine) is detectable at four parts per trillion! Over those thresholds, such smells can get worse. Hence, humans are good at sniffing out wine faults as well as pleasant odours, which is a whole other related subject.
How it works
How does it work? The roof of each nostril has a region known as the nasal mucosa. This region contains up to ten million highly sensitive receptor cells, of which there are about a thousand types. Each type is sensitive only to its own narrow range of odourants.
When we inhale, the odourants dissolve in mucous and then bind onto the receptor cells. Those cells send messages to the olfactory bulb and, in turn, to the brain for interpretation. We can combine odours into patterns, distinguish between them and even recognise and memorise them. Some are attractive, others repulsive. Some odourants can combine to present new complexities. You will have your own culture-created set for some of these odours, that may trigger a powerful emotional response or memory.
Orthonasal and retronasal smelling
This process is orthonasal smelling. The details of how it happens continue to be studied. There are a lot of variables and stages between sniffing a glass of wine and perhaps showing a smile of appreciation or recognition milliseconds later.
Textbooks usually say that humans can discriminate between 10,000 distinct odours. However, a controversial study suggests a human capacity of one trillion different scents. Regardless, it demonstrates that the sensitivity of the human nose allows us to detect and appreciate the most subtle aromas and flavours, even when fleeting.
So smelling a wine before sipping is a critical step in both enjoyment and analysis, and is also why other smells can easily interfere. In wine judging, not smoking or wearing perfume is essential etiquette. And it’s why pairing wine and food is an art in itself.
The mouth also plays a part in smell, with a crucial aspect called retronasal smelling. Here, volatile odourants are released in the mouth by sipping, chewing and swallowing/spitting. They travel to the olfactory senses via the nasal passages. This process helps determine the length of the wine, the duration of a particular taste, and the flavours occurring on the finish.
Taste is a word with many shades of meaning but here refers only to our neurological ability. There are several types of taste-bud that exist on the tongue and elsewhere in the mouth. These distinguish between five primary tastes; sweetness, acidity, bitterness, saltiness and umami. The detection is helped by saliva and using the tongue to stir the wine throughout the mouth. And interaction with saliva helps us appreciate astringency, minerality, freshness and the balance between wine components.
Taste-buds are fragile things and luckily they are continually renewed. How else could we withstand the full-on assaults of Vindaloo, Coke or fags?
As for so-called supertasters, some individuals have more of a specific type of taste-bud, which can heighten sensitivity to bitterness. Bitterness often indicates potentially harmful poisons, so it could be a useful evolutionary trait.
However, the term supertaster is misleading because being a supertaster doesn’t make you a better wine taster. At best, it might get you a job as a Cup-bearer to prevent assassinations. Apply with your CV to your local Despot. “How I am galled – mightst bespice a cup, To give mine enemy a lasting wink, Which draught to me were cordial.”**
Nature versus Nurture
While there are genetic differences which give a “normal” variation in human senses, the vast majority of us are born with excellent and innate sensorial abilities. But each of the five senses can be developed in the brain through culture and practice, learning and memory. And these senses may act independently or in unison, but it’s up to the brain to sort through the jumble, recognise patterns and present a unified picture.
Consequently, nature is essential, but nurture takes over. Possibly some are born as potentially better wine tasters because of some genetic predisposition. But in my opinion, what makes one person able to “taste better” than another is predominantly a learned skill that also needs practice.
Also, without the ability to recognise, memorise and articulate in language, knowledge cannot be shared with others in a meaningful way, let alone agreed upon!
You can do it too
This means that most people can taste what a “professional” wine taster or enthusiast tastes. They are just unfamiliar with technique or how to articulate it. Unfortunately, the portrayal of wine tasting is too often elitist, specially maintained by a cadre of elitists. However, it’s just another skill that anyone can learn, practice, and be good at.
Who is the judge of whether you like something or not? You are. Yes, of course, we can learn a great deal and be encouraged by others. There are no wrongs and rights in our preferences and interpretations. But we can improve how we recognise and share them. To avoid repetition, this is something explored briefly in Silly Tasting Notes and Neuroenology.
Lastly, our abilities will vary, according to gender, age, hormonal balance, and biorhythms – over which we may have little or no control. However, time of day, hunger or satiety, and emotional state (for example, excitement, boredom, anger, happiness, depression) are also significant influences that we can manage.
To sum up, determining how our senses, brain, emotions and language work together in wine tasting is rocket science. But tasting and enjoying wine isn’t, it’s only a process of consciously exercising our senses. Consequently, its merely a journey anyone can take. I’m living proof of that.
I’ll leave you with this, which for me sums it all up rather well.
“And I can see, hear, smell, touch, taste.
And I’ve got one, two, three, four, five,
Senses working overtime.
Trying to take this all in
I’ve got one, two, three, four, five,
Senses working overtime.
Trying to taste the difference ‘tween a lemon and lime,
Pain and pleasure, and the church bells softly chime.”***
*A Neurologist would doubtless add more to these five, but for the purposes of this article I’ll stick with Aristotle
** Shakespeare, The Winter’s Tale, Act 1, Scene II
***XTC, Senses Working Overtime, 1982