It’s usually said that the human tongue can detect only four basic tastes: sweet, sour, bitter and salty, and that all tastes are combinations of these. Many specialists now believe that taste is actually more complicated than this, with the taste buds being helped along by sense of smell, by the feel of substances in the mouth and even by the noise that food makes when we chew it.
In recent years some workers have added a fifth taste, umami, to the other four, though western food scientists are divided about whether it really exists or not. It has been suggested that the taste is triggered by compounds of some amino acids, such as glutamates or aspartates, especially the flavour-enhancing substance monosodium glutamate.
Both the word and the concept are Japanese, and in Japan are of some antiquity. Umami is hard to translate, to judge by the number of English words that have been suggested as equivalents, such as savoury, essence, pungent, deliciousness, and meaty. It’s sometimes associated with a feeling of perfect quality in a taste, or of some special emotional circumstance in which a taste is experienced. It is also said to involve all the senses, not just that of taste. There’s more than a suggestion of a spiritual or mystical quality about the word.