Human taste detects at least five basic qualities, including savory umami.

Taste begins when chemicals from food or drink stimulate specialized receptor cells. These cells are gathered in taste buds, and their messages reach the brain through nerves involved in taste rather than through a single universal flavor pathway.

Umami is the savory quality associated with glutamate, a substance found in foods such as broths and some meats. Recognizing umami explains why a savory sensation cannot be described adequately as just a mixture of sweet, salty, sour, and bitter.

The familiar tongue map is misleading. Cells responsive to different basic qualities are distributed across the tongue rather than confined to separate exclusive zones, so sweetness is not restricted to the tip or bitterness to the back.

The National Institute on Deafness and Other Communication Disorders describes taste as one of the chemical senses. Microscopic substances released from food interact with sensory cells in the mouth and throat. Taste cells cluster in taste buds, including those on the tongue, roof of the mouth, and lining of the throat. The visible bumps on the tongue are not themselves individual taste buds, although some types contain them.

Taste receptor cells communicate with nerve fibers that carry information toward the brain. There, incoming messages contribute to the recognition of basic taste qualities. Sweetness, sourness, saltiness, bitterness, and umami describe categories of sensation, not a list of every food a person can recognize. An apple and a sweetened drink may both taste sweet while differing greatly in aroma, texture, acidity, and the overall eating experience.

The distinction between taste and flavor becomes especially clear during a cold. Chewing normally releases aromatic molecules that can travel from the mouth and throat toward receptors high in the nose. Congestion can interfere with this route. Someone may still detect sweetness or saltiness while finding familiar foods bland because much of the aroma information is missing. What feels like lost taste can therefore be primarily a smell problem.

Other sensations add further dimensions. Nerve endings help register the burning of hot peppers and the cooling effect of menthol, while touch supplies information about crispness, smoothness, or thickness. These experiences matter to flavor without making each one a separate basic taste. Saying there are at least five established qualities leaves room for scientific investigation of additional candidates without treating every distinctive mouth sensation as an already accepted sixth or seventh taste.

NIDCD distinguishes a basic taste quality from the identity of an entire food. Sweetness describes one dimension of an experience, not a unique label for a particular ingredient or meal. A food may combine sweetness with sourness, aroma, texture, and temperature. The five established qualities therefore describe components of flavor rather than five boxes into which every eating experience must fit.