How does our sense of taste work?

The tongue is covered in small bumps called papillae, many of which contain taste buds, and each bud holds roughly 50 to 150 receptor cells. When food dissolves in saliva, its chemicals bind to receptors that respond to sweet, sour, salty, bitter or umami, the savoury taste of glutamate. Nerves carry these signals to the brain’s gustatory cortex. Much of what we call flavour actually comes from smell, as aromas travel from the mouth up to the nose, which is why food tastes bland with a blocked nose. The old “tongue map” showing different tastes in separate zones is a myth; all areas can detect all five.