Sweet, sour, salty, bitter and umami (Japanese: full-bodied spicy) - these are the five flavors we can distinguish. Our taste buds are the microscopic structures that are responisible for our ability to taste. They sit on the tongue, palate and epiglottis, and we have roughly 2000 to 5000 of them as adults. With increasing age, we tend to lose taste buds. In addition, research shows that we may even be able to taste other nuances like spiciness, coolness (menthol, for example) or fat.
People used to think that every single flavor has a well-defined area in the mouth, especially on the tongue. Sweet at the top, bitter in the back of the tongue area, salty and sour at the border of the tongue, etc. Today, we know that taste is perceived in all areas of the mouth, but some tastes are experienced better in some areas.
Taste is an experience that begins before our food or spices even enters our mouth. We experience taste and flavor with all of our senses: our eyes capture the color, consistency and appearance of food, generating an expectation for taste. THe noses registers the scent of our food, which triggers memories in our brains. Special electric impulses are triggered by the tastes buds, which then travel to our brain and allow us to experience flavor.
Certain nerves make the connection between the taste buds and the central nervous system in the brain. Next stop: the cerebral cortex. Here the taste stimuli are detected and assembled with the olfactory impressions to form a complex flavor perception. Then the brain measures these impressions and helps us decide if we do or do not enjoy this flavor.