WHAT THE RESEARCH SAYS

Same plate,
different flavours.

Two people can eat the same mouthful and taste quite different things.

A generous bunch of fresh coriander on a wooden chopping board beside a knife, limes and a red chilli — AI-generated image, not a photograph of a real person or place.

Bitter genes vary
Smell genes vary more
Habit does the rest
Why taste is personal

Part of the reason is in our genes: in bitter-taste receptors and in hundreds of smell receptor genes. Part is learned, from the foods we grew up with to the one meal that made us ill.

Updated 16 October 2026

THE SHORT ANSWER

Genes set the dial,
experience turns it.

Three findings on why taste differs
from person to person.

CORIANDER

Soapy for some

A study of 14,604 people linked tasting coriander as soapy to a genetic variant among smell receptor genes, near OR6A2, which binds the herb's aldehydes. The effect was small.

Check a food

BITTERNESS

A famous lab accident

In 1932 a scientist found that PTC dust tasted bitter to colleagues but not to him. Variation in one gene, TAS2R38, explains much of the difference.

See the numbers

LEARNING

We learn to like

Many preferences are shaped by what we are used to, especially as children. People new to fermented foods often find them disgusting but can learn to like them.

Learning to like

A QUICK FOOD CHECK

Is it your genes
or your history?

Pick a taste reaction to see what the research says about it. The bar shows how much of the difference between people is linked to genes.

Based on the University of Utah's Learn.Genetics, the University of Delaware's Myths of Human Genetics and a 2012 genome-wide study of coriander taste.

Taste check

Choose a reactionA test strip tastes horribly bitterBroccoli or dark chocolate is too bitterCoriander tastes of soapBlue cheese or kimchi seems offA food that once made you ill

A test strip tastes horribly bitterMostly one gene

Differences in tasting PTC and PROP are mostly due to variation in TAS2R38. About 25% of people taste nothing at all, though the trait is less simple than the classroom version.

Broccoli or dark chocolate is too bitterMany receptors

Bitter-sensing cells carry about 25 known types of bitter receptor. Variation in their genes helps explain why one person loves dark chocolate and another cannot eat it.

Coriander tastes of soapSmall genetic part

A variant near the smell receptor gene OR6A2 was linked to the soapy taste, but the heritability tagged by common variants was low, about 0.087.

Blue cheese or kimchi seems offMostly learned

Fermentation creates sour, sharp flavours and off odours. People who grow up with these foods love them; newcomers can learn to like them over time.

A food that once made you illLearned aversion

Conditioned taste aversion is one of the most powerful forms of learning. One bad experience can put you off a food, even if the food was not the cause.

Sources: Learn.Genetics (University of Utah), Taste and Smell; J. H. McDonald, Myths of Human Genetics: PTC tasting; Eriksson et al. (2012), arXiv 1209.2096.

TWO NUMBERS WORTH KNOWING

A quarter taste nothing,
and we all smell differently.

One figure on a classic bitter test,
one on the genes behind smell.

≈ 25%

People to whom PTC and PROP taste of nothing

To some people these chemicals taste intensely bitter, to others mildly bitter, and to about a quarter they have no taste at all.

BITTER TASTE · LEARN.GENETICS

≈ 400 genes

Human genes that code for smell receptors

Each gene codes for a receptor that responds to a different set of molecules, and each comes in two versions, one from each parent. The mix helps decide which smells you notice.

SMELL · LEARN.GENETICS

Learn.Genetics notes that the flavour of chocolate comes from more than 600 different molecules, which the brain blends into one sensory experience.

A wedge of blue-veined cheese and a small bowl of red fermented cabbage on a rustic wooden table — AI-generated image, not a photograph of a real person or place.

FOUR THINGS TO TRY

Explore your
own palate.

None of these is a test of anything. They are simple ways to notice how personal flavour is, based on what the research describes.

Compare notes on coriander
Ask friends whether it tastes fresh or soapy. You are likely to find both answers at one table.
Follow a smell
Smell is tied to memory and emotion, so notice which food smells take you back to a particular place or time.
Try a food again
Preferences shift with exposure, so a taste rejected years ago may be worth another go.
Notice changes with age
Studies found sensitivity to PTC tends to be lower in older people, so taste can change over a lifetime.

LEARNING TO LIKE

Born with some tastes,
taught the rest.

Some preferences are built in: babies like sweet things and reject bitter ones. But much of what we enjoy is shaped by what we ate as children and by the foods of our culture, from spicy dishes to fermented fish.

Smell is closely tied to memory and emotion. Learn.Genetics explains that smell signals go directly to brain areas for emotion and memory, which is why one smell can make one person gag and another feel at home.

Steamed broccoli florets and squares of dark chocolate side by side on a plain white plate — AI-generated image, not a photograph of a real person or place.

Questions

Questions people ask

Why does coriander taste like soap to some people?

Its aroma comes largely from aldehydes. A 2012 study linked the soapy taste to a genetic variant near OR6A2, a smell receptor gene that binds several of those aldehydes, though genes explained only a small part.

What is PTC?

Phenylthiocarbamide, a chemical that tastes very bitter to some people and of nothing to others. It was discovered by accident in 1932 and is often used in classroom genetics.

Is bitter tasting controlled by a single gene?

Mostly but not entirely. TAS2R38 explains much of the variation, but family and twin studies show it is more complicated than the simple dominant-recessive story.

What is a supertaster?

Someone highly sensitive to PTC and PROP. They may find vegetables and citrus unpleasantly bitter. Contrary to popular belief, they do not have more papillae on their tongues.

Can I learn to like a food I dislike?

Often, yes. Many preferences are shaped by exposure, and people who first try foods like strong cheese or fermented fish as adults may learn to like them over time.

Same plate,
different flavours.