Why Two People Smell the Same Wine Differently

If ten people smell the same glass of wine and describe it ten different ways, this is not a failure of tasting. It is a feature of human perception.

One of the most persistent frustrations for wine students, judges, and professionals is the belief that there is a single correct aromatic truth hidden in the glass. There is not. Wine does not exist as a fixed sensory object. It exists as a chemical signal that is interpreted by a biological system, varying from person to person.

Understanding why people smell wine differently is essential if you want to move beyond guessing and toward real sensory mastery.

Smell is not a Camera. It is a Biological Filter

The nose does not record aroma. It translates it.

Just as the eye does not capture color but interprets wavelengths of light, the olfactory system interprets volatile molecules through receptors that vary between individuals. This translation process is inherently personal.

When volatile compounds rise from a glass of wine, they enter the nasal cavity and bind to olfactory receptors. These receptors do not function identically in all individuals. No two individuals share the same olfactory receptor profile.

This means that two people smelling the same wine are not receiving identical sensory input before memory, language, or expectation ever enters the picture.

The differences begin at the biological level.

Genetic Sensitivity Determines What You Can Smell

Humans possess roughly 400 functional olfactory receptors encoded by approximately 350 to 400 active genes, out of nearly 1,000 olfactory receptor genes in the genome. These genes exhibit extensive variation due to single nucleotide polymorphisms, small genetic differences that alter receptor structure and function.

The result is a dramatic variation in sensitivity to specific aroma compounds.

Some individuals detect certain molecules at extremely low concentrations. Others require much higher levels, and some may not detect them at all.

This is not a subjective opinion. It is measurable biology.

Well Documented Examples in Wine

Thiols (3MH, 4MMP)
These sulfur-containing compounds drive aromas such as passion fruit, grapefruit, boxwood, and blackcurrant bud in wines like Sauvignon Blanc. Detection threshold studies show variation spanning orders of magnitude. Some tasters detect these compounds intensely at concentrations below 5 nanograms per liter. Others barely register them, even at levels above 50 nanograms per liter.

Methoxypyrazines (IBMP)
Responsible for green bell pepper, cut grass, and herbal notes, particularly in Cabernet Sauvignon and Sauvignon Blanc. Sensitivity to isobutyl methoxypyrazine varies widely. One taster may detect it at a concentration of 1 to 2 nanograms per liter. Another perceives it only above 15 nanograms per liter. A third may not perceive it at all until concentrations exceed 30 nanograms per liter.

TCA (2,4,6 Trichloroanisole)
The compound responsible for cork taint exhibits extreme detection threshold variation. Some individuals detect it below 1 nanogram per liter. Others do not perceive it above 10 nanograms per liter. This explains why disagreements over whether a bottle is corked are common even among professionals.

None of this reflects intelligence, experience, or training. It reflects genetics.

Specific anosmias, or selective smell blindness to individual compounds or chemical families, are well documented. Similar phenomena exist for vanillin, asparagus metabolites, androstenone, and other aroma compounds relevant to wine.

Detection Thresholds are not Universal

Every aroma compound has a detection threshold, but that threshold is not fixed across people.

Think of smell the way you think of hearing. Some people hear high frequencies better than others due to differences in cochlear structure. Smell works the same way, but with chemical receptors instead of hair cells.

One taster may detect a compound at one part per trillion. Another may require ten times that concentration. Both are normal. Both are tasting correctly for their biology.

This is why consensus tasting is difficult and why professional panels require calibration with reference standards. It is also why self-doubt is so common among students who assume disagreement means incompetence.

It does not.

Memory Determines Recognition

Smell is the most memory-dependent of all the senses.

Olfactory signals project directly to the piriform cortex and limbic system, including the amygdala and hippocampus, regions responsible for emotion and long term memory formation. Unlike vision or hearing, smell bypasses the thalamus, making odor perception highly associative and deeply personal.

You cannot recognize what you have never smelled.

If you have never encountered quince paste, you will not identify quince in a wine. If you grew up around eucalyptus trees, you may recognize that aroma instantly. Someone else may describe the same compounds as minty, medicinal, or camphor-like.

The aroma does not change. The mental library does.

This is one of the strongest arguments for structured aroma training. Recognition improves not through repetition alone, but through targeted exposure paired with explicit naming. Labeled memories become anchors that dramatically accelerate future recall.

Language is Often the Real Barrier

Many people smell accurately but struggle to describe what they perceive.

This creates the illusion of sensory failure when the real problem is linguistic.

Aroma perception and verbal description are two different cognitive skills. One does not automatically produce the other. Psycholinguistic research shows that odor naming is particularly difficult because smells are rarely labeled during acquisition, unlike visual or auditory experiences.

Common barriers include:

• Knowing the smell but not the word
• Knowing the word but hesitating to say it
• Overcomplicating descriptors to sound credible
• Freezing under social or exam pressure

This is why experienced tasters often sound simpler, not more complex. Precision beats poetry. “Black cherry” is more useful than an elaborate metaphor.

Context Alters What You Smell

Sensory perception does not occur in isolation.

Lighting, temperature, ambient noise, fatigue, stress, expectation, and prior information all influence what you perceive. This is extensively documented in sensory science literature.

If you are told a wine is expensive, you are statistically more likely to perceive complexity. If faults are suggested beforehand, you will detect them faster. Fatigue measurably reduces chemosensory sensitivity.

This is why professional tastings control variables. Neutral lighting. Standardized glassware. Absence of perfumes. Temperature control. Consistent timing.

Remove noise. Isolate signal.

Disagreement does not Mean Error

One of the most damaging myths in wine education is that disagreement means someone is wrong.

• Two tasters can both be correct
• One taster may detect compounds that another cannot
• Descriptors may differ, while perception overlaps
• Language choices may obscure agreement

For example, one person says black cherry, another says dark plum. These are not opposing views. They are neighboring references describing similar aromatic drivers.

Understanding this builds confidence and reduces intimidation, particularly in exam and judging contexts.

Why Aroma Training Works

Genetics defines the starting point. Training determines how far you go.

Aroma training cannot change your receptors. It cannot make you smell compounds you are biologically blind to. But it dramatically improves:

• Recognition speed
• Memory anchoring
• Descriptor accuracy
• Confidence under pressure

Structured aroma systems work because they remove ambiguity. You know what you are smelling. You repeat it. You label it. Over time, recall becomes automatic and cognitive load drops.

Professional tasters converge not because they smell identically, but because they communicate accurately within a shared framework.

That is the goal.

The Goal is not Agreement. It is Accuracy

Professional tasting is not about matching notes with your neighbor. It is about:

• Identifying what is chemically present
• Avoiding false positives
• Communicating clearly
• Remaining consistent across evaluations

Wine does not change from glass to glass. People do.

A great taster is not the one who smells the most things. It is the one who understands what they smell, why they smell it, and how to articulate it without hesitation.

That is the difference between guessing and mastery.

About the Author

Sébastien Gavillet is COO of Wine Aromas - Le Nez du Vin. A renowned wine and whisky expert, winemaker, and distiller, Sébastien has been working with Le Nez du Vin for over 25 years. He is the author of Discovering and Mastering Single Malt Scotch Whisky and the International Whisky Guide series. He serves as a panel chair and examiner for The Council of Whiskey Masters, shaping global tasting standards and mentoring the next generation of spirits professionals.