It is commonly accepted that our tongues have taste receptors that allow us to perceive five primary taste modalities: salt, sweet, bitter, sour and umami. To this list, some food scientists have added a sixth taste known as kokumi. The first four tastes are pretty straightforward – the last two less so.
The word umami is derived from the Japanese root "umai," meaning "delicious" or "good." Umami loosely translates as a "pleasant savory taste" or "essence of deliciousness." Though there is no equivalent English term for umami, it can be best described as "a pleasant broth-like, meaty, savory taste with a mild but lasting aftertaste that stimulates salivation and creates a coating sensation or furriness on the tongue." Umami is the prevalent taste experience in fermented foods. Foods considered to have a strong umami flavor include aged beef, Parmesan cheese, balsamic vinegar, fish sauce, soy sauce, Worcestershire sauce, miso, seaweed, tomatoes and dried mushrooms.
Even harder to describe than umami is a more recently identified taste quality known as kokumi. Kokumi is sometimes translated as "heartiness" or "mouthfulness" and describes compounds in foods that don't have their own flavor, but enhance the flavors with which they're combined. In cooking, kokumi develops over time; a long-simmering stew will have greater kokumi than the same food tasted early in preparation. An in-depth exploration of kokumi will appear in a future column.
Umami usually develops through cooking or fermentation. Raw beef doesn't have umami the way a seared steak does. Our prehistoric ancestors developed a preference for cooked and fermented foods, a trait they share with dogs, gorillas and chimpanzees. Uncooked, potentially rotten meat could be full of pathogens. The evolutionary development of taste receptors that responded favorably to cooked and fermented foods enhanced human survival.
Umami was first "discovered" in 1907 by Kikunae Ikeda, a chemist at the University of Tokyo. The origin story goes that while Ikeda was eating a bowl of his wife's dashi soup, he detected a savory flavor that was distinct from the four basic tastes of sweet, sour, bitter and salty. He named this additional flavor "umami." Dashi, the mother stock of Japanese cooking, is a light, savory stock made by briefly boiling and straining kombu seaweed (giant kelp) and katsuobushi (a fermented, dried fish). Dashi is not only delicious on its own, but amps up the flavor of many other savory foods. Ikeda suspected that something in the seaweed might be the source of dashi's unique flavor-boosting ability.
At his lab, Ikeda ran dashi through a series of evaporations to isolate its individual chemicals and found it to be predominantly glutamic acid. It turned out that kombu seaweed has one of the highest concentrations of naturally occurring glutamic acid of any food and concluded that this was the source of umami.
Realizing the flavor-enhancing potential of his discovery, Ikeda developed a process that produced a sodium salt of glutamic acid through microbial fermentation of sugar cane. Monosodium glutamate (MSG) became widely used in Asian cuisine and appeared on Western grocery shelves as Accent Flavor Enhancer. MSG became controversial and fell out of favor in the 1960s after a letter to the editor of the New England Journal of Medicine implicated MSG as the cause of "Chinese restaurant syndrome," a claim that research has subsequently revoked. Nowadays, MSG is found in Chick-fil-A's fried chicken and in the popular snack nacho-cheese-flavor Doritos, which contains five separate forms of glutamate.
More recently, food scientists determined that in addition to the glutamic acid from seaweed, dashi also contains the free nucleotide disodium inosinate (IMP), provided by the katsuobushi. Research has shown that glutamates and inosinates interact together, not just in an additive way, but in a multiplicative way, essentially becoming eight times more flavorful when tasted together. It was also discovered that another free nucleotide, disodium guanylate (GMP), which is present in shiitake mushrooms, has a similar multiplicative effect on taste when eaten in conjunction with glutamates. Dried shiitake mushrooms are often substituted for katsuobushi when a vegan dashi is desired. Both IMP and GMP are considered "flavor potentiators."
Foods high in umami increase saliva production, literally making your mouth water. Saliva is a palate cleanser, and it enhances your ability to taste food. People experience umami through taste receptors that typically respond to glutamates and nucleotides, both of which are widely present in meat broths and fermented foods. Umami taste receptors exist not only on the tongue but also in the gut. Human breast milk is rich in glutamates.
Home cooks desirous of creating more deliciousness in their savory dishes can achieve this boost by incorporating components that are high in umami. All the ingredients in this recipe, when combined, deliver a major umami punch that can elevate even a ho-hum grocery store steak.
Pan-seared steak with red wine mushroom sauce
2 steaks, about 8-ounces each
1 cup red wine
6 dried porcini mushrooms
4 tablespoons unsalted butter
½ pound fresh mushrooms, sliced (cremini, button, oyster, shiitake or a combination)
1 medium shallot, minced
2 cloves garlic, minced
2 tablespoons finely chopped sun-dried tomatoes (optional)
1 tablespoon tomato paste
1 tablespoon ketchup
1 teaspoon fish sauce
2 teaspoons Worcestershire sauce
¼ teaspoon MSG
Salt and freshly ground black pepper
2 tablespoons high-heat oil, such as grapeseed
Allow the steaks to come to room temperature, and season liberally with salt and black pepper.
In a small saucepan, bring the wine to a boil and blanch the porcini mushrooms for 2 to 5 minutes. Strain the mushrooms through a coffee filter, reserving the wine. Rinse the rehydrated mushrooms gently in cold water and pat dry.
In a large skillet, melt the butter over medium high heat. Add the fresh and rehydrated mushrooms, shallots, garlic, sun-dried tomatoes, and sauté until the mushrooms are golden-brown. Stir in the tomato paste and ketchup and cook a few minutes longer until the pan starts to dry.
Add the wine and scrape the bottom of the pan with a wooden spoon to loosen the browned bits and reduce until slightly thickened. Stir in the fish sauce, Worcestershire sauce and MSG. Set aside and keep warm.
In a heavy skillet, heat the oil until shimmering and sear the steaks, turning once, until desired doneness. This should take between 3 to 5 minutes per side. Remove from the heat and rest for about five minutes.
Season the mushroom sauce to taste with salt and pepper. Serve atop the steaks.
Peter Glatz is a second-career chef currently touring the United States.