“Is fish sauce just a form of MSG?” —Danielle Sommerville
Fish sauce is an indispensable ingredient in the cooking of Vietnam, Thailand, Burma, Cambodia, Laos, and the Philippines. The potent liquid is made by salting and fermenting fish (usually anchovies) for months, an ancient method for preserving a seasonal abundance of fresh protein. (it’s not specifically Asian; the Romans, for instance, relied on a similar liquid they called garum.) In the kitchen, fish sauce, like a dab of anchovy paste, is transformative, both amplifying and deepening the flavors in a dish or dipping sauce that would otherwise taste flat. Think of it this way: You would miss it if it weren’t there.
And is it a form of monosodium glutamate (MSG)? Well, yes. MSG is the commercial counterpart of glutamate, which results when glutamic acid, a naturally occurring amino acid, is cooked, fermented, or ripened. It’s found in almost all foods, including mushrooms, walnuts, meats, fish, kelp and other sea vegetables, tomatoes and other vegetables, fermented soy, and cheeses—in particular, Parmigiano-Reggiano. Whoops, almost forgot—glutamate is also present in milk, including human breast milk. In fact, 40 grams of glutamate are produced every day in the human body, where it’s necessary for brain function and metabolism.
Glutamate’s reputation as a flavor enhancer—and the subsequent development of its cheap, ubiquitous commercial form—has its roots in Japan, specifically, the northern island of Hokkaido, where the salty-sweet brown kelp known as kombu—integral to the sea stock called dashi—is harvested. (Ramen noodles, anyone?) In 1908, the chemist Kikunae Ikeda, a professor at Tokyo Imperial University, found that kombu contained a high concentration of glutamate, and he isolated the savory, almost meaty taste sensation he called umami, or “deliciousness.” (By the way, I couldn’t find one online link to Professor Ikeda that didn’t perpetuate the myth of the four basic tastes: bitter, sweet, sour, and salty. If you’re interested in the science of flavor, read Bruce Feiler’s “The Corrections” in the July 2008 Gourmet and prepare to have your world rocked.)
These days, almost any protein can be broken down to make MSG, and the additive is used in all manner of processed foods to make them taste better. Now, I know that even though MSG has been recognized as safe by the EU, USDA, and medical establishments the world over, there is a small percentage of people who react to foods containing MSG (a.k.a., those suffering from Chinese Restaurant Syndrome). Their symptoms include headaches, flushing, sweating, fuzzy thinking, heart palpitations, numbness, and tingling. Am I alone in admitting that I had a number of these symptoms on many a first date? And as far as the last two symptoms go, didja eat something seasoned with Sichuan peppercorns? If so, you are supposed to go all numb and tingly.
All kidding aside, food sensitivities are extremely difficult to diagnose for a number of reasons, and even the results of placebo-controlled studies are drowned out by anecdotal—and very real—experiences to the contrary. If you are among those who want to avoid adding (more) MSG to your diet, you should be aware that as far as food labels are concerned, it lurks in a wide range of ingredients, including yeast extract, “broth,” and “natural flavorings.”
But back to a far more enjoyable subject: fish sauce (nuoc mám in Vietnam; nam pla in Thailand). If you love to cook Southeast Asian dishes and are unfazed by MSG, then there is no reason whatsoever to avoid using fish sauce, packed as it is with its natural glutamate. Generally speaking, fish sauce from Vietnam (or a Vietnamese-style sauce made in Thailand) is lighter and more delicate than a Thai-style sauce, which is geared to the heavier, spicier food of that country.
For more information, I turned to Andrea Nguyen, author of Into the Vietnamese Kitchen: Treasured Foodways, Modern Flavors (available at your local independent bookstore or at Amazon). Her marvelous blog, Viet World Kitchen, has a terrific post on how to buy fish sauce. And don’t be shy about branching out. I’ve been cooking my way through Naomi Duguid’s Burma: Rivers of Flavor, and I’ve been impressed by how accessible it is. In fact, it’s a window into a whole new cuisine and culture. Pass the fish sauce.