For most of the 20th century, schools taught that the tongue had four basic tastes: sweet, sour, salty, and bitter. That count was wrong. In 1908, a Japanese chemist named Kikunae Ikeda noticed that some foods - soups, cheeses, ripe tomatoes - had a flavor that didn’t fit any of the four. He isolated the substance responsible (glutamate) and named the new taste umami, which means “delicious” in Japanese.
It took the rest of the world almost a century to catch up. In 2002, scientists confirmed that the tongue has specific receptors for umami, completely separate from the receptors for the other four tastes. Today, umami is officially the fifth basic taste.
While we’re correcting old facts: the “tongue map” you might have learned in school - sweet on the tip, bitter at the back - was based on a misreading of an old German paper. Every part of your tongue can taste every flavor. Different areas are slightly more sensitive to certain tastes, but all five are detected pretty much everywhere.
