Sweet, sour, bitter, and salty. These flavors are all pretty easy to describe. But there’s a fifth flavor, umami, that’s equally as important as the others, but not nearly as easy to get a grasp on. Chances are, if you’ve ever been to a Japanese or Chinese restaurant, you’ve sampled this unique taste. Read on to learn more about the elusive flavor and why it took so long to discover.

What is umami?

A simple, if inadequate, way to put it would be that umami is a savory flavor. Think beef, fish, and cheese. But before you assume that umami is merely a trait of meat and dairy products, consider that tomatoes and mushrooms also pack a healthy dose of umami flavor.

To understand how this is, we have to begin with the fact that umami taste comes from glutamic acid. When glutamate breaks down, it becomes L-glutamate, which is really what we think of when we think of umami. And glutamate can break down in many ways: when a steak cooks, when a tomato ripens under the sun, or when soy sauce ferments. This is the key trait that links umami foods together.

How scientists (finally) recognized umami

Before we get to the scientists, let’s be clear: chefs recognized umami way before anybody in a lab coat did. The French chef Auguste Escoffier knew there was something distinctive about his popular veal stock back in the 1800s. It wasn’t just sweet or bitter or sour or salty.

But it took until the next century for a Japanese chemist named Kikunae Ikeda to identify glutamate as the common thread between the meats, cheeses, and veggies that share the umami taste. He tasted in dashi—a popular Japanese broth—something similar to what Escoffier’s patrons tasted in his veal stock, and then he was able to isolate glutamate as the culinary culprit.

That was in 1908. It wasn’t until 2002 that Ikeda’s discovery became scientific consensus, however. The reason for this? Scientists finally proved that the human tongue indeed has receptors for five distinct tastes—a biological basis for declaring umami its own flavor category.

How you can recognize umami

If somebody was unfamiliar with sweet flavors, you could tell them to eat a big bowl of sugar. It’s not quite so straightforward with umami, but there are still plenty of ways to hone your palate. Anything slow-cooked, especially soups or broths, is a great place to start. A Japanese shiitake soup really drives this point home, as does almost anything made with miso. And for something more distinctly Western, savor some parmesan cheese.

Umami or MSG?

Since umami and MSG are both so ever-present in Asian cuisine, it’s easy for people to confuse the two. So what is the difference between umami and MSG anyway? Not much, as it turns out. MSG is a manufactured form of umami. It’s similar to how a vitamin supplement is a manufactured form of nutrients that naturally occur in foods.

As such, there’s reason to be skeptical of most claims that MSG causes unpleasant side effects. Anyone who truly experiences discomfort from eating MSG-heavy Chinese food should feel similar effects from, say, a bowl of spaghetti with tomato sauce and parmesan.

Or perhaps an even better example would be the popular chain Umami Burger, whose signature burger—topped with dried-mushroom-and-seaweed powder and a sauce of Marmite and soy—is basically a large hadron collider for umami taste.

And to bring it all back around, here’s one more way the two substances are intertwined: MSG was first patented by Kikunae Ikeda, the Japanese chemist who discovered umami.