Why Everybody Is Hooked on Fish Sauce

Melanie S. Byrd is a professor at Valdosta State University in Georgia, and the co-author of "Cooking Through History: A Worldwide Encyclopedia of Food with Menus and Recipes."

"The precise origin of the first fish sauce is unknown, and a source of debate among historians," Byrd says in an email. "Vietnam is often cited as one point of origin. Fish sauces and pastes were a part of ancient Chinese cooking."

It's known as nuoc mam in Vietnam and here it's made with just anchovies and salt. The best supposedly comes from Phú Quốc, a small island in the Gulf of Thailand.

Likewise, Thailand, Cambodia and Indonesia all have rich traditions of fish sauce usage. "There are different varieties of fish sauce in different Southeast Asian countries, and names vary according to language, country, and specific ingredients and flavoring," Byrd explains.

In Thailand, fish sauce is known as nam pla and is saltier than nuoc mam. It's also made of anchovies and salt, but oftentimes includes sardines, mackerel, herring or carp, as well as sugar.

Byrd says fish sauce is also commonly used in Korea and Japan, but it's mostly associated with Asia's coastal southeast.

Geography helps explain why. Mainland Vietnam has a coastline that's 2,025 miles (3,260 kilometers) long. Thailand's coast is 1,956 miles (3,148 kilometers) long — and the various shorelines of Indonesia add up to a whopping 50,300 miles (81,000 kilometers) of seaside terrain.

Plus, the region has a wealth of rivers, streams and ponds teeming with fish and crustaceans. So naturally, fishing is a pretty huge deal across Southeast Asia.

Just like all wines are not made using the same type of grapes, fish sauce can be made with a number of different sea creatures.

Anchovies are the common base ingredient for fish sauce. But as mentioned, some fish sauces might include herring, carp or mackerel — even krill.

No matter what type of fish is used, the critters must be salted before the magic can begin.

"The complex flavor [of fish sauce] comes from the fermentation process of bacteria breaking down the salted fish," says Byrd. "Fish, usually small fish like anchovies or krill, are salted and packed in barrels and left for several months to a couple of years."

Pham says Red Boat Fish Sauce ferments their sauce for about 12 months.

"Red Boat specializes in fish sauce produced on Phú Quốc Island, Vietnam," Pham says. "Phú Quốc has a global reputation of producing the best fish sauce out of Vietnam. Historical records tell us that people have been making fish sauce on Phú Quốc Island for over 200 years."

While you may think you've never eaten fish sauce, there's a pretty good chance you have. If you've ever eaten pad Thai or phở, for instance, you've had fish sauce.

Fish sauce has a surprisingly pungent aroma, but don't let that put you off. Its flavor, however, isn't overwhelmingly fishy. It's much more complex. It has notes of umami from the fish and salt, plus notes of earthiness and mushrooms similar to soy sauce. But its finish has an almost caramel-y sweetness.

The complexity makes fish sauce ideal for flavoring marinades and broths, or pumping up the taste of stir-fried cabbages, greens and other Asian-style side dishes. When you combine fish sauce with other ingredients, the sauce mellows out and its umami side amplifies, so it can be used to replace salt in a lot of savory dishes. Just remember the two distinctive flavor profiles of nuoc mam and nam pla — and that just a little goes a long way.

Asia was not the only continent to fall in love with fermented fish-based sauces.

"As in ancient China, ancient Greeks and Romans also made fish sauce, called garos or garum. Though it fell from use in the later Roman Empire in the west, it remained a condiment for a while in the Byzantine Empire," Byrd says. Romans used to smear garum over bread, eggs, meats and vegetables.

When the volcano Mount Vesuvius erupted in 79 B.C.E., it smothered the Roman city of Pompeii underneath a blanket of hot ash. That left six barrels once used for garum manufacturing exquisitely preserved for thousands of years — until researchers found them in 2009.

Chemical clues inside these artifacts, along with ancient written recipes that've survived to the present day, tell us a lot about how garum was made.

Byrd says the process involved salting the entrails of small fish, such as sprats, anchovies or mullets, and allowing the mixture then to ferment or macerate in the sun for several months. Herbs and other ingredients were often added.

"Many food historians suggest that the Greco-Roman garum was similar to the Vietnamese fish sauce, nuoc mam, which is still a staple in Vietnam," Byrd says.

To Pham, the condiment's enduring appeal is no mystery. "Fish sauce is the secret ingredient that will have everyone asking for your recipe!" she says. "It deepens the flavor of your dish and adds a savory, umami note."