How Your Nose Makes Sense of Complex Whisky and Wine
You close your eyes and raise the glass to your nose.
Dark berry fruits, an old leather armchair, and fresh pencil shavings all emerge within a magnificent bouquet.
But here’s the thing. Obviously none of these objects are bobbing about in your chosen tipple. So how is it that we can picture them so vividly?
It becomes even more remarkable when we consider that each of these scents is made up of hundreds of individual odour molecules, yet your brain interprets them as a single, unified aroma such as an old leather armchair. This is the magic of odour objects, the brain’s ability to take chaotic sensory inputs and transform them into something meaningful. But how does this happen? And what does it mean for the way we experience tasting whisky, wine, and other complex drinks?
What Are Odour Objects?
Unlike vision or hearing, where the brain can clearly separate components (e.g., different musical notes in a chord, or different colours in a rainbow), odour perception is an illusion that the brain creates. This means that instead of processing each odour molecule individually, the brain groups related odorants together to form a single perceptual experience that we associate with a physical thing – such as a pineapple.
So if we look at the molecules that make pineapples smell like pineapple, for example, many different molecules combine to create the experience. But rather than the brain identifying each individual molecule on its own, it views them as a collection of molecules that it associates with pineapples. These associations between specific groups of molecules and things are what we call ‘odour objects’.
A sense such as vision is considered a direct sense, meaning that we see individual colours on a spectrum in a direct way. But olfaction, the sense of smell, is considered a synthetic sense. Aromas are created in the brain as opposed to being a real-world representation of molecules. For example, while wine may smell of gooseberries in your brain, there are no actual gooseberries in your glass. You can read more about this illusion here: How Your Brain Creates Taste and Perception.
How the Brain Builds Odour Objects
The olfactory bulb sits at the top of the nasal cavity and is the data relay hub for smelling. Odour receptors detect molecules and send the information to the olfactory bulb. But this information is chaotic and messy, so it’s the role of the olfactory bulb to organise the signals into patterns.
The unique selling point (USP) of the olfactory bulb is that it connects directly into the brain. In fact, for all intents and purposes, it creates a bridge between the brain and the outside world via the odour receptors. Once the olfactory bulb has grouped the information together it sends the signals to the piriform cortex, often called the “’olfactory cortex’. This is where the brain codes and organises this information into meaningful odour objects.
Here’s how it works:
Pattern Recognition - The brain doesn’t store smells like a chemical inventory. Instead, it learns patterns and creates neural templates for specific odours. For example, after repeated exposure, the smell of peat smoke becomes a recognisable odour object, not just a mix of phenols.
Memory and Association - The piriform cortex communicates with the hippocampus, which links smells to memories and experiences. This explains why certain aromas instantly transport you to specific places, like a dram of whisky reminding you of sitting around a beach bonfire.
Adaptive Coding - The brain can rewire itself based on familiarity and exposure. If you drink a heavily sherried whisky enough times, your brain will refine the ‘sherry bomb’ odour object, making it easier to identify and even predict specific nuances within it.
Odour Objects Are Flexible and Subjective
A common misconception is that flavour, or aroma more specifically, is a static experience. At a whisky tasting or wine tasting it’s common to believe that because flavour ‘appears’ to be in the glass, its character is an absolute thing and it’s up to the taster to identify it. But since odour objects are constructed in the brain, they are not absolute. This is why:
Our unique life experiences will create a different set of odour objects in the brain when compared to another person. What one might call ‘coconut’, another might say ‘toasted oak’. It all depends on what are most familiar to us.
The same whisky or wine can smell different depending on what you’ve eaten, your mood, or how fatigued you feel. The drink hasn’t changed, but you have.
Odour perception can evolve over time. Research has demonstrated how familiarity with certain odours can make them seem more pleasant. What once smelled overpowering might later become nuanced and delightful with diligent effort.
Hence, aromas are subjective experiences that are in a constant state of flux. How we perceive odour molecules will vary throughout each day, and because odour objects are created by the brain, it’s important to understand that no flavour experience is set in stone.
The Role of Context and Expectation
Your brain doesn’t just identify smells, it interprets them based on context. This is why the same set of molecules can be perceived differently depending on how they are experienced:
Orthonasal vs. Retronasal Olfaction – Odours reach the nasal cavity from both sniffing and from sipping a drink. The scent of a whisky when nosed (orthonasal) can feel quite different from when it is tasted (retronasal), even though the same molecules are involved. Read more about it here: The Surprising Secrets of Taste and Smell.
Expectations and Biases - If you are told that a whisky is rare and expensive, your brain is primed to perceive more complexity and depth. The same whisky, presented in a basic bottle with no fanfare, may not evoke the same experience.
Cultural Differences - People from different cultures often construct different odour objects. A whisky that smells richly peaty to a Islay fan might register as medicinal or even unpleasant to someone unfamiliar with phenolic compounds.
How This Affects Whisky Tasting
Understanding odour objects can transform how we approach tasting whisky or wine. Here’s why:
There Are No Right or Wrong Tasting Notes
Since flavour perception is a brain-generated experience, every taster constructs odour objects differently. This means that divergent opinions are valid, and there is no single ‘correct’ way to describe a whisky.
Descriptive Language Can Shape Perception
The vocabulary used to describe aromas influences what we perceive. If a whisky is described as having ‘candied orange peel’ notes, tasters may be more likely to detect that specific aroma, even if they wouldn’t have noticed it otherwise.
The Brain Fills in Gaps
Because some odour patterns may not be entirely complete, the brain can fill in missing sensory information. For example, you may smell a whisky that almost smells like old leather, but not quite. So the brain fills in the gaps and identifies it as the closest odour object, in this case old leather. This means that subtle flavours may not need to be strong to be perceived, our brain will reconstruct them if it expects them to be there.
Understanding Odour Objects Can Help Train the Palate
If you want to become better at tasting, the key isn’t just memorising flavour wheels, it’s training your brain to recognise odour patterns more efficiently. Repeated exposure to a wide variety of different smells helps refine the brain’s ability to construct odour objects with greater precision.
Conclusion: Rethinking How We Smell and Taste
The next time you sniff a whisky or nose a wine, remember that you aren’t just detecting molecules, you are constructing an experience inside your brain. Flavour isn’t in the glass; it’s an illusion created by your mind, that’s shaped by memory, context, and expectation.
By understanding odour objects, we can:
Become more open-minded about how others perceive whisky.
Develop more refined tasting skills by actively smelling and tasting different experiences that the brain considers to be odour objects, i.e. sniffing fruits, vegetables, and flowers.
Understand that whisky appreciation isn’t about ‘right’ or ‘wrong’ descriptors, it’s about the rich, unique, and personal experience of flavour.
So, the next time someone tells you a whisky smells like banoffee pie or croissants, just smile, because that’s their odour objects. What’s yours?
If you enjoyed this and are hungry for more, check out our online course: Professional Whisky Tasting. It’s packed full of insights such as odour objects, explained clearly and in a way that helps to enhance your tasting skills, whether you’re a complete novice or a seasoned professional.