Barring actual poisons, is there any foodstuff more vilified than MSG? One might point to saccharin, or the supposedly Mikey-cidal combo of Pop Rocks and soda, but it's hard to beat MSG's toxic haze of associations: Ringing ears. Headaches. Brain lesions in rats. Top Ramen. That's why I was surprised to see chef David Chang quoted in November's Food & Wine on the appeal of the dread ingredient. According to the piece, he uses Kewpie mayonnaise from Japan in the lobster rolls at his restaurant Momofuku, claiming that it is "the best mayonnaise in the world, because it has MSG." Was he just being cheeky? Or could Chang be on the leading edge of an MSG revival?
One thing is certain: MSG's prospects have been greatly improved by the food world's recent embrace of umami, the basic taste that is now an accepted addition to the old quartet of bitter, salty, sour, and sweet. (We perceive complex flavors in food when these fundamental tastes, picked up by receptors on our tongues, are supplemented by the more nuanced aromatic data we gather with our noses.) Umami and MSG have long been conflated. In 2000, when the journal Nature first reported the discovery of an umami taste receptor, it explained that umami is "better known in the west as monosodium glutamate (MSG)."
The relationship is not quite that simple. David and Anna Kasabian detail the intertwined history in their well-researched book The Fifth Taste: Cooking With Umami,which was released late last year. In 1907, a Japanese chemistry professor named Kikunae Ikeda detected what he believed was a distinct taste in a bowl of soup. (The soup was most likely dashi, a Japanese staple brewed from kombu seaweed and dried bonito flakes.) Ikeda hypothesized that the satisfying, savory taste of the soup was discrete and could not have been cobbled together from aromas or the four other basic tastes, which were already well-known at the time. He studied kombu and isolated the source of the taste: an amino acid called glutamic acid and known in its salt form as glutamate. Ikeda called the taste umami—which translates roughly as "delicious essence"—and set about creating a form of glutamate that could be used as a food additive. That's MSG, to you and me.
Connoisseurs argue that naturally occurring umami—found in glutamate-rich foodstuffs like mushrooms and parmesan cheese—is far superior to its synthesized cousin. But when they try to explain what's so great about the "delicious essence," they inevitably resort to verbal mushiness. When umami is not being written off as "the taste of MSG," it is described as "meaty," "brothy," "savory," or, vaguely smuttily, as "mouth-filling." The Kasabians suggest that umami might be "the taste of protein," since glutamate is abundant in breast milk and many meats. I think of umami as a scrumptious roundness in food, akin to a lovely cello note. It's not a taste I would have isolated on my own (I'm not as perceptive as Ikeda), but once I read about it, I recognized it.
Whatever umami is, people like it. By 1909, monosodium glutamate was being marketed in Japan as the flavor enhancer Aji-no-moto, which is still available today. MSG was a quick, cheap way to mimic and reinforce the taste of glutamate-rich foods like dashi, fermented beans, and fish sauces. It also made meat-poor dishes seem meatier and quickly became popular throughout Asia.
In the United States, however, MSG was slower to catch on. It had a presence in Asian restaurants and industrially processed foods, but despite the efforts of the makers of Ac'cent, MSG never became the third shaker on the American kitchen table. And after World War II, people began to blame the additive for everything from brain lesions to Parkinson's. Most commonly, it was linked to "Chinese food syndrome"—which also goes by the less racist name MSG symptom complex—a nebulous collection of symptoms that can include headache, flushing, and heart palpitations. None of the most serious accusations have held up in double-blind studies, and though ingesting large quantities of the stuff may induce unpleasant, but temporary, symptoms in some consumers, the FDA has repeatedly failed to find dietary MSG a threat to the general public health. Still, Asian restaurants often feel compelled to label their menus MSG-free.
Beyond any health risks, real or imagined, MSG suffers from its association with cheap food and its stigma as cheat. Salt and vinegar and lemon peel and sugar are considered legitimate ways to balance the salty, sour, bitter, and sweet tastes, but there isn't really an analogous way to tweak a dish's umami quotient. Sure, there are fish and soy sauces and parmesan cheese, but their non-umami flavor components can be pretty aggressive. Before MSG came along, some Chinese cooks made use of umami flavor-boosters called taste essences—usually pastes made of dried fermented wheat gluten or soybean proteins. But even these were frowned upon as unnatural additives.
Despite the stigma, MSG does its job effectively. When I added a pinch of crystalline MSG powder to one of two cups of light duck broth I'd made, I got a sense of its power. The broth without the MSG tasted good, but slightly thin. The Aji-no-moto-fied portion tasted fuller, as though there had been more to the broth than water and duck parts, and it also tasted slightly reduced. American cooks often toss a bouillon cube—likely to contain MSG—into soup or a sauce to make it seem richer. Using pure MSG, you cut out the middleman. But there are limits to its appeal: Too much MSG, like too much salt, makes food taste worse, not better. And unlike salt, which, when used properly, tends to be forgotten, MSG-laced dishes all have that same mushroomy taste—eat too many and you get a case of déjà goûté.
It's not surprising, then, that the chefs who contributed recipes to The Fifth Flavor—among them Nobu Matsuhisa and Daniel Boulud—boost umami with natural glutamate-rich sources like soy sauce and parmesan. Very few trendsetting chefs are willing to brush off the "natural is better" philosophy that has dominated the food scene for decades. There is science-friendly Heston Blumenthal of the Fat Duck, who isn't afraid to rub shoulders with MSG-boosters: He showed up at a seminar sponsored by the Umami Information Center, an umami-industry trade group. But he and Chang are probably outliers.
Even so, that doesn't mean you're avoiding MSG. The ingredient is simply hiding in plain sight. It thrives in the industrial food world, where it is known affectionately to scientists as E621. The next time you eat your favorite binge-inducing snack—Cool Ranch Doritos, say, or a McDonald's sausage McGriddle, or those little Japanese crackers wrapped in nori—lick the flavor dust off your fingers and read the ingredient label. You're quite likely to find MSG. If not, it is likely that some other glutamate-rich flavorant is producing the same taste. (Hydrolyzed soy protein, autolyzed yeast, and sodium caseinate, to name a few, all serve essentially the same purpose as MSG.) In their book, the Kasabians call the manufacturers' bluff: "Some would say that the public's widespread distrust of MSG has deeply moved food makers—not to take glutamate out of their food, but to find ways of delivering it under unassuming pseudonyms."