“A scent is worth a thousand pictures.” Dr Rachel Herz, Neuroscientist
Aroma is a fundamental aspect of whisky, but we experience aroma through a complex combination of chemical reactions, and electrical signals, with our own interpretation of those signals in light of our emotional state and experiential background. This is an area that continues to fascinate me as it greatly influences the scores we provide on Malt, and the weight which Malt’s readers put on our individual opinions.
Aroma, or odour, is fascinating in a sociological and historical context. It now plays the smallest part in the human experience relative to history. Certainly, this is true in the West. Gen Z and Y, often known as Centennials, have been surveyed as stating they would choose to give up their sense of smell before an item of technology such as their phone or laptop. In language, smell and our noses are often presented most often with negative connotations; “that smells” or “keep your nose out.”
Ancient Greeks are said to have put more effort into planning the olfactory experience at a feast than the eating. They used significant amounts of wild herbs and spices to enhance the party, and burned incense to take away the smell of food. In ancient Rome fountains were “sweetened” to enhance the atmosphere around them, and amphitheatres employed numerous techniques to enhance the smell experience. Christianity, strangely, has a lot to answer for here; certain smells were determined evil, while sweet, perfumed smells were heralded as a sign of righteousness. This is true from the very arrival of Jesus and the gifts of frankincense and myrrh. Priests were supposed to give off a sweet odour, and incense is still burned in church in certain denominations.
Our sense of smell and perception of aroma begins within the womb, and is exceedingly important for the initial bonding between mother and baby. Olfactory growth is a key part of our childhood development; it is believed we start with no genetic predisposition to smells, as a blank slate that is populated by learning. Flowers-smell-sweet is a common early association. Each new smell learned is associated with knowledge, experience, and emotion at the time that the smell was encountered. The next time that smell is encountered, the brain is preprogramed to react, for example to recoil from foul smells much as one learns not to touch a hot cooker.
As a result, our sense of smell, our appreciation and identification of aromas is deeply personal. Naturally, there will be common ground where the majority of people experience smells in a similar way. Generic ground coffee perhaps? This may be true of Western cultures, but the experience of coffee and coffee recipes and presentation certainly varies around the world. Even in the West, statistically there will be those who find coffee off-putting. I absolutely love to read John’s tasting notes, as his aroma-experiences living in the Philippines and travelling around Asia give an exotic and appealing profile in the whiskies he reviews. This article on a range of Douglas Laing whiskies is a good example.
Aroma, our sense of smell, and eating and drinking have a highly complex relationship. Our sense of smell is critical to our experience of flavour. Our taste sensation on our tongue is very basic. You can get five main tastes from your tongue: sweet, salty, sour, bitter, and umami. Once you introduce your sense of smell, you will get thousands of flavours.
We smell in two distinct ways. When we breathe in through our nose we smell the odour molecules in the air, known as orthonasal olfaction. We also smell through the back of the mouth – as we chew, the air passes out the nose – known as retronasal olfaction. The odours in your mouth will be different from the odours you inhaled through your nose, therefore you will get a more complex perception of flavour when you experience both. When nosing whisky, we are often encouraged to open our mouths. This allows the air we breathe in through our nose to fully circulate in the nasal cavity and react with both forms of olfaction.
This is true of holding the whisky in your mouth, too; breathing in slightly can deliver different flavours. When holding whisky in our mouths the warm air from our lungs will also take the odour molecules up into the nasal receptors. This retro-nasal pathway is unique to humans because we evolved without a transverse lamina and with a common tube for our digestive system and respiratory system. Not only does it allow us to make complex speech, but it allows us to hold food or liquids in our mouth and breathe over it, giving a much greater flavour perception. It seems a shame not to maximise this evolutionary advantage by using these nuanced tasting techniques.
We should also bear in mind that each nostril is individually contributing when we are nosing whisky. The nostrils take turns to engorge the nasal membrane with blood, most likely to help fight germs and bacteria breathed in. This nasal cycle allows for different air flow rates in each nostril. Different aroma molecules in the air will reside in each nostril for different periods of time. Allowing for each nostril to identify differences between “quick” volatile molecules and “slower” less-volatile molecules gives much greater depth of perception of smell by the olfactory receptor.
The volatility of scent molecules is crucial to perfume creation. It is also a fundamental part of the whisky making craft of Dhavall Ghandi at The Lakes Distillery, but I think that could be a whole article in itself. If you want to hear more about top notes in whisky this SMWS podcast is worth a listen.
The psychology of aroma is a fascinating aspect that regularly comes up when tasting notes are discussed. How can a whisky remind you of waves breaking on a beach, of summer rain in childhood, or a wood-panelled library? The psychology and neuroscience is, complex but includes the initial recognition of the smell and secondly the launchpad of a memory which may or may not be related to the smell itself. Most of our interaction with smell are very mundane but some can be unique markers that would have become attached to a memory. How this occurs with smell more than other senses is due to the wiring of the brain.
Olfactory System. Source: Neuro News & Cosmo Clues
Now I am definitely getting out of my depth a little here technically, but my understanding is that the signals from the olfactory bulb – which interprets the interaction between the chemical molecules and the olfactory receptor cells – are initially processed by the amygdala, followed by the thalamus. The amygdala helps coordinate responses to things in your environment, especially those that trigger an emotional response.
The thalamus is a mostly grey matter structure of the diencephalon that has many essential roles in human physiology. The thalamus is composed of different nuclei that each serve a unique role, ranging from relaying sensory and motor signals, as well as regulation of consciousness and alertness. Therefore – unlike other senses which are first interpreted and reasoned with by the thalamus – the aromas can directly link with emotions within the amygdala. This also results in first memory associations with smell being extremely strong and difficult to change.
As we evolved, we were likely to encounter danger in the form of smells that needed to be quickly imprinted into our thoughts. These aroma associations are difficult to change; if your first experience of peaty whisky was at university, drinking too much, making a fool of yourself, ruining your chance with a potential love match, and then waking up in accident and emergency, it is unlikely you will be able to easily shift that negative connotation. You may never enjoy whisky.
There is an upside to all this emotional linkage: if you associate the aroma of whisky with a positive, relaxing feeling you will become more relaxed drinking it, less stressed. This reduction in stress and increase in calm has been proven repeatedly to have a physical impact on your immune system, clearing out stress hormones and boosting your ability to fight infection. Long story short, we can confirm that drinking whisky is good for you… if you drink it responsibly, that is!
Whisky drinkers will be interested to know that you can train you sense of smell by actively and consciously smelling the aromas in the world around you. For example, smelling fruits can help you define and be more specific about “fruity” aromas. This, too, is very good for your brain, as the nature of the smell sense means that during smell training a large part of the brain is activated. Smell training is particularly good for brain development and can mitigate some of the effects of aging that can dull the smell sense much like hearing and eyesight deteriorates. Call it the second health benefit to drinking whisky, so long as you are actively engaged with smelling the aromas!
This would not be a whisky review site without a review, so here is a slightly different take on our normal format. I’ll be evaluaing this one on aroma, exclusively:
Thompson Bros “Distilled in Sutherland” (Clynelish) 2000 – Review
Bottled to celebrate the 20th Anniversary of Dornoch Castle Whisky Bar. Aged 19 years. 53.3% ABV. £150.
On the nose: Heavy rich ripe fruits, over ripe melon, buttery shortbread, custard creams, windfall apples, waxy dried apricots, musty pineapple juice, baked apples, a faint whisp of peat, Liquorice Allsorts, pine needles.
I dipped more deeply into the aroma of this whisky, for longer than usual, which was a great experience. I knew the nose of this whisky would be inviting and alluring but I definitely got a greater experience from concentrating on the nose itself. I definitely noticed that one nostril felt more effective than the other due to the nasal cycle and could detect a benefit from the circulation of the aromas from both orthonasal and retronasal olfaction.
This article was developed for whisky drinkers from the excellent podcast series An Aromatic life with Frauke Galia, which I recommend readers drop into to explore. Additional information came from Dr Rachel Herz’s TEDx Talk. All other sources directly referenced.