Salty, sweet, sour, bitter. Sure, those taste receptors on the tongue seemed obvious enough. But the savory flavor of umami as a distinct taste? Western scientists had long dismissed the idea—but it was proven a long time ago in the flavor’s spiritual home of Japan.

Imperial University of Tokyo scientist Kikunae Ikeda discovered the flavor in 1907, after studying the compounds in kelp that his wife used when making stock from the sea-bound stalk, according to The Economist magazine. Ikeda called it umami (which literally translates to “delicious taste”) and developed it just a year later into the now well-known crystals we call “MSG” (monosodium L-glutamate). Just a tiny bit will transform nearly any basic dish into a savory spectacle (paywall).

Ikeda published his paper in Japanese shortly after making his discovery, but umami didn’t make any impact in Western culture. In fact, scientists for decades declined to accept the presence of umami receptors on the human tongue—little areas that notice glutamate. Even still, that didn’t stop others from adopting Ikeda’s creation. Within 20 years, MSG became a go-to in Japanese kitchens, spread further into Asia, and even into the rations of US soldiers during the Second World War—a nifty way to make otherwise bland rations more palatable. It found its way into potato chip for companies as big as Pringles.

It wasn’t until the mid-1980s that “savory” began to be recognized as a discernible taste and Ikeda’s findings were proved to be correct.

According to the Umami Information Center, a non-profit organization founded in 1982 to represent the taste, umami itself does cause a chemical reaction in the body. ”Umami… serves as a signal to the body that we have consumed protein,” the center says on its website. ”Sensing umami triggers the secretion of saliva and digestive juices, facilitating the smooth digestion of protein.” It can also be found in vegetables, shellfish, mushrooms, and even in some cheeses.

Fast-forward to today and umami is comparatively huge. It’s become a trend, even, as its reach has transcended Japanese home cooking and has found its way onto grocery store shelves in Western countries—witness the rise of instant noodles. The flavor has even inspired restaurant chefs like Momofuku guru David Chang, who used it as a base for a kind of “unified theory of deliciousness.” Umami Burger is a Los Angeles-based chain that’s made a name for itself by seasoning its meat with umami.

Umami isn’t the only taste that scientists have isolated and suggested join the ranks of official tastes. In 2016, murmurs from a contingent of the scientific world began advocating that flour-tasting ”starchiness” become an officially recognized flavor, too. That one hasn’t yet made the cut.