What is umami? Why the 'fifth taste' is so difficult to describe

• Umami is the savory or meaty taste sensation that makes your mouth water.
• Scientifically, it's the presence of glutamic acid, usually combined with nucleotides.
• To add umami to your food, try mushrooms, seaweed, tomato paste, or cheese.

Umami, or savory flavor, has been a hot topic in the food world over the past decade. TV chefs casually mention it as they're adding tomato paste or fish sauce to a dish, and there's even a fast-casual restaurant chain called Umami Burger.

Believe it or not, though, umami was only discovered in 1908. Tokyo Imperial University professor Kikunae Ikeda realized that a seaweed called kombu (a staple in Japanese cooking) contained an amino acid called glutamate that gave it a meaty flavor. Ikeda coined the word umami, which roughly translates to "pleasant savory flavor."

The term moved into more popular usage in the latter half of the 20th century. It's since gained a reputation as the "fifth taste" - the one that's not salty, sour, sweet, or bitter. And it seems to be the toughest one to nail down.

We chatted with Pat Polowsky, a food scientist based in Madison, Wisconsin, and Sarah Wassberg Johnson, a food historian based in New York City's Hudson Valley for more context on the science, the history, and the flavor of umami.

The science of umami

"When things interact with our tongue, they're called tastes," says Polowsky. Salt and sour and acid are unique in how they interact with our tongue, they're simple chemicals that we have channels for. Everything else, meaning sweet, bitter, and umami, we have specific g-coupled protein receptors that are specific to certain compounds."

If you don't know what a g-coupled protein receptor is, that's okay. Essentially, all our tastes rely on receptors on our tongue, some of which are more complex than others. Umami is one of the more complex tastes.

Glutamic acid, sometimes called glutamate, gets a lot of credit for umami flavor, but Polowsky says there's more to it than that. Five-prime nucleotides, tiny building blocks of DNA and RNA, are also an important part of the umami experience.

"Basically, umami is an evolutionary response signaling protein," says Polowsky. "If you find these compounds together in the wild, cooked protein isn't far away." In other words, we need protein to thrive, so nature made it delicious.

Salt can help amplify our experience of umami, says Polowsky, though he adds, "that's kind of cheating because salt amplifies most flavor experiences." Umami can help temper bitterness as well.

So what does it taste like?

Umami is a savory or meaty flavor. You may associate it with a Sunday roast, a perfectly charred hamburger, or even Doritos. A bowl of ramen is packed with umami thanks to the seaweed, mushrooms, and soy sauce. A cozy, satisfying bowl of red sauce pasta is also rich in umami, thanks to the tomato.

But, umami is as much a sensation as it is a flavor, says Polowsky. "It induces salivation - even to a greater degree than acid. It literally is mouth-watering."

Umami rich foods

"We in America kind of always understood the value of the meaty savory flavor, we just never bothered to identify it," says Johnson. For example, tomato-based ketchup was common in the 19th century and precursors to it were made with walnuts, anchovies, and mushrooms. She also cites "meat-based extracts" popular in the late 19th and early 20th centuries used to make broth and enhance the flavors of other dishes.

Today, there are plenty of readily available ingredients that can add an extra boost of umami to your food.

• Mushrooms: Polowsky notes that there's a huge concentration of five-prime nucleotides in dried mushrooms. They can be added to soups, broths, pots of beans, and more. Fresh mushrooms have umami too, though in less concentrated doses.
• Tomatoes: The quintessential sweet-meets-savory flavor of tomatoes is thanks to glutamic acid. Tomato paste is an even richer form of umami.
• Beef: Beef, especially the long-cooked cuts like brisket and chuck, have a high concentration of umami. Traditionally, beef has been a major source of umami in the American diet, says Johnson. She adds that Americans have eaten more meat than almost anybody else in the world since the 19th century
• MSG: "The vilification of MSG was based in pseudoscience and racism," says Polowsky. "There's never been any conclusive or even hinting evidence that it's a health hazard." MSG stands for monosodium glutamate - and remember, glutamate is the very amino acid that creates the taste sensation of umami. Polowsky keeps a shaker of MSG to add to his cooking. "I use it in basically everything," he says.
• Fish sauce: Fish sauce is a condiment whose deep umami flavor comes from fermented fish. Today, it's more widely associated with Southeast and East Asian cuisines, but the ancient Romans had their own version of it as well. Chef David Chang has said that he adds fish sauce to his pasta dishes for a quick boost of umami.
• Parmesan: Many cheeses, especially longer-aged ones like Parmigiano Reggiano, have highly concentrated umami. Another umami-rich cheese is the French sheep milk blue cheese Roquefort.
• Seaweed: Seaweeds like kelp, dulse, kombu, and nori are naturally rich in umami. In fact, it was nori that lead Ikeda to discover umami. If you don't already cook with seaweed, an easy way to add it to your food is by keeping around a jar of furikake, a Japanese seasoning containing nori, to sprinkle on rice, fish, and other foods.

Insider's takeaway

There's a lot to learn about the science and history of umami, but you also can learn a lot about it in a functional sense by trying different sources of umami in your meals. If all else fails, just keep a shaker of MSG around for a quick hit of savory, mouthwatering goodness.

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