Flavour is mostly smell
What is called flavour is largely retronasal smell — odorants from the mouth reaching the nose — together with taste, touch, and temperature.
Established2 min read
The tongue and the palate detect a short list: sweet, sour, salty, bitter, umami, and a few debated others, plus texture, heat, and pain. The variety of 'tastes' in a kitchen is odor. Molecules go up the back of the throat to the olfactory epithelium while you chew. That route is retronasal, and it is most of flavour.
This is why a cold dulls dinner, and why wine language is a language of smell even though the wine is in the mouth. The brain binds the two senses into one percept and then assigns the whole thing, wrongly, to the tongue.
Caveats
- Taste is real. Sugar is still sweet with the nose closed. What vanishes is the identity of the fruit.
- The binding can be broken by experiment and by congestion. It is not a permanent confusion of the nerves.
Sources
- 1Shepherd G. M.. Smell images and the flavour system in the human brain. Nature 444, 2006.