What’s the first question we instinctively pose to ourselves when pouring a glass of vino we haven’t tried before? For how many of you is it – ‘What can I smell in that?’
The bond of shared rituals
A certain theatrical bond has evolved around the handling of wine at a consumer level that no other drink shares quite so strongly. The art of smelling, describing the smell and questioning others on whether they share your smell experience is a spectacle I first observed as a teenager at home from my Sri Lankan mother. The same ritual is also reciprocated among many guests at my wine bars on a daily basis irrespective of culture, age, or level of wine knowledge.
if only you can detect the pencil shavings, forest floor and wild strawberries does that make you a bona fide wine pro?
Is it fair that we expect others to smell what we do in the glass? And if only you can detect the pencil shavings, forest floor and wild strawberries does that make you a bona fide wine pro?
What are aromas?
To unpack this, we first need to understand what aromas are. Any chemical compounds in your glass of wine light enough to float in air and physically reach your nose would be classed as an aromatic compound. From a scientific viewpoint, the free-floating aroma compounds which emerge from a glass of wine can be measured and documented by olfactometers and mass spectrometers. But, depending on how certain aromatics combine in a mixture or medium, they’ll then go on to smell like entirely different things. Even with lab equipment it’s tricky to understand how a person might perceive certain matrices of aroma compounds since there are so many aromatic combinations at play, and all at differing concentrations.
When we get a waft of delightful Châteauneuf-du-Pape aromas we imagine these aromatic compounds travelling up our nose to be picked up by our orthonasal system (the bit that detects all the smells), with information sent to our olfactory bulb in our brain which does all of the smell processing. This aroma from our wine glass arrives in a medium of oxygen-rich atmosphere and at room temperature so will only include aroma compounds that are made available at that temperature and mixture.
Swallowing helps you smell
The other half of this smelling process comes after we swallow. As we gulp our Châteauneuf the wine is superheated by our body Heavier aromatic compounds that were once too inert to leave the glass are now made more volatile and start to enter a gaseous state, just like a bowl of soup will smell more when heated up. As we breathe out, this extra dimension of smell rejoins our carbon dioxide-rich exhale and triggers our orthonasal system with an entirely different set of data. This second hit of aroma post-swallow is referred to as retronasal olfaction. Our olfactory bulb simultaneously merges the data from both in and out smells to create a better picture of what we’re smelling. In short, swallowing helps you smell.
Differing aroma thresholds affect what we smell
What really throws a spanner in the works is that we each individually have differing aroma thresholds to specific smells. These thresholds determine whether we register smells below certain concentrations or not. For example, If I have a high threshold for the green capsicum pepper smelling methoxypyrazine and you don’t, then it’s more than likely when smelling and sipping our bottle of Châteauneuf you’ll detect green pepper, but I won’t. Now apply this to the thousands of aroma compounds found in a glass of wine and our differing aroma thresholds for each from person to person. This means we will individually tend to smell the aroma compounds we have lower thresholds to than others.
Can you smell black pepper?
Additionally, in extreme cases certain individuals may be anosmic to specific aromas. This means that regardless of the concentration of a specific aroma, anosmic individuals simply won’t be able to detect it at all. A smell blindness of sorts. Sesquiterpene rotundone is responsible for the black pepper aroma in your bottle of Châteauneuf yet 25% of the general population are anosmic to it.
Already we’re starting to see how and why we all smell different things in the same glass of wine. In most cases no matter how hard we try, we’re not ever going to smell the same aroma picture as the person beside us.
Speed counts – how’s your sniff velocity?
The speed of smelling is another factor that plays a key role in what we pick up. Odour molecules all have different rates of sorption into the mucus of our olfactory systems, where heavier molecules will often require more time (deeper heavier sniffing) much like a hoover being passed over a particularly stubborn patch of carpet. Sniff velocity is a real game changer when sniffing wine and to develop a wider aroma picture I encourage you to mix up your sniffing pace!
we have all struggled to formulate a sentence around describing wine aroma yet never fail to link a smell to a memory.
Swirl it. Sniff it. Say it!
So far, we have discussed the aroma measurement tools we’re biologically equipped with. Let’s take this one step further to how we articulate this information, to language. Our Wernicke and Broca's part of the brain is responsible for language processing. It’s also incredibly far away from our olfactory bulb which does all of our smelling calculations. This directly reduces our Information Processing Capacity (IPC) which, put simply, means that we’re naturally not so good at it. Inversely our amygdala – which processes emotions and memory surround the olfactory bulb – they’re directly connected. This explains why we have all struggled to formulate a sentence around describing wine aroma yet never fail to link a smell to a memory.
We are all unique odour detectors!
Human biology and neuroscience show we are all fallible and unique odour detectors. Like wine itself, we are the outcome of place and genetics. But does knowing this now make the most earnest of question of ‘What should I be smelling here?’ somewhat existential?
