Many countries claim fish sauce, but Naomi Duguid has a compelling theory about the origins of Southeast Asia’s most important ingredient.

Part 2 in Naomi Duguid’s Fish Sauce Chronicles. Check out Part 1 here.

Traditionally, fish sauce hasn’t made many friends outside of Southeast Asia. It was like Tibetan butter tea is to most non-Tibetans: smelly and incomprehensible.

I remember in the mid-nineties chatting about Thai food to a well-known (American and Eurocentric) food writer who said something like, “yes but that awful fish sauce…it’s so overpowering!” The writer would probably deny saying it now.

In the last decade fish sauce has become “normal”; these days it would be uncool to dislike it. North Americans have come to love Vietnamese and Thai food, from curries to dipping sauces. In all of them fish sauce is the indispensable ingredient.

It may be the lifeblood of Southeast Asian cuisine, but the fish tale begins in Europe.

There are a lot of claimants, but the earliest signs of fish sauce come from ancient Rome, and a fish-based liquid called garum, as well as its more refined first cousin “liquamen.” They were used as a salty seasoning, and also, as we understand now, gave an umami depth of flavor, just as modern-day fish sauce does. I’ve been teaching a food history course recently and have come across a lot of research by academics and impassioned amateurs who believe that the Greeks or perhaps the Phoenicians were the ones who came up with the fish sauce idea first. The Romans then took it on. With fish and salt both plentiful in the Mediterranean, it was an affordable and effective way to store the catch.

Once the discussion moves to Southeast Asia, well…every country claims fish sauce as its own and most take this claim very seriously. There are the Chinese, who say that soy sauce and dao jiao (fermented soy beans) are the vegetable/soy version of fish paste and fish sauce, which were a Chinese invention. The argument is that the idea traveled south from China, either with migrants overland or with traders, as rice-noodle-making seems to have. Then the Vietnamese, whose nuoc mam is now famous, of course take ownership, and the Cambodians (their word is tuk trey), and the Thais, whose nam pla is the fish sauce most widely available in North America, in a wide range of brands. And let’s not forget the Burmese, the Filipinos, the Japanese.

But I think in Southeast Asia it must have started with the Khmer. After all, their great kingdom centered at Angkor controlled not just present-day Cambodia but also what is now southern Vietnam. They needed a method of preserving fish, because every year the great lake, Tonle Sap, yielded a staggering catch.

It works like this: the lake swells as monsoon rains raise the level of the Mekong so much that it flows back up and fills the lake. The floodwaters bring nutrients in the form of eroded soil from upstream (all the way from Tibet, Sichuan, and Yunnan), and that feeds the fish in the lake. By the time the water level drops, as the monsoon ends and the Mekong water levels go down, the lake drains south. With a lot less water and a lot more fish, for centuries, every October-November has been fish harvest time around the Tonle Sap. How to preserve the catch?

You can dry it, but it’s much safer and more practical to pack it with salt and preserve it. The cruder country version of fish sauce, which is how it must have begun, is called prahok in Khmer. It a combination of salty water and softened fermented pieces of fish, very pungent. Fish sauce is a much refined descendent of prahok.

Yes, of course, the idea could have come in from elsewhere, but it seems to me there’s a good argument for the Khmer, whose kingdom depended on the riches of the Tonle Sap, being the originators of fish sauce in the region. Another supporting argument is that in Southeast Asia there’s what I call the “fish sauce line”. North of it, people didn’t traditionally use or make fish sauce. That includes the Shan (also known as Tai Yai) who live in northern Burma and Thailand, and other Tai peoples who live in Yunnan, including the Tai Lu, also known as Dai. They use fermented soybeans and dried shrimp to give dishes that umami flavor Asian cultures love, but traditionally fish sauce has no place in their pantry.

I’m an outsider though, a North American, and fish sauce is a local subject, tied up with pride and identity, just as olive oil or bread is for people in parts of Europe. Each country and culture takes pride in its own version of fish sauce and fermented fish, and lays claim to having invented it. My Khmer theory would prove more than a little controversial in, say, Thailand or Vietnam. That’s why, despite writing a number of cookbooks on regional Asian cuisine, I’ve been shy about discussing origin theories: I don’t want to step on anyone’s toes.

It’s not about “the right answer”. Instead I think it’s about appreciating the human creativity and ingeniousness that figures out how to take advantage of what food possibilities are out there, and turn them into delicious sustaining foods that nourish us in body and imagination.


I have been deeply imprinted with Thai fish sauce since 1980, so now that is my go-to version, rather than the Vietnamese fish sauce that first initiated me. Try them. If you are lucky enough to come across Cambodian or Burmese fish sauce, buy a bottle. Try the Philippine version, called patis.

If you are trying to decide which one to buy, check the ingredients list and avoid those that contain anything more than salt, fish, and water; many have sugar, which I think muddies the flavor. But you may like the effect, so don’t hesitate to try them all, so you can judge for yourself. Buy a number of different brands and do a taste test (one of fish sauce’s great virtues is that it’s cheap and it goes a long way).

Use fish sauce as a seasoning for sauces, a base for a marinade, or make a simple nuoc cham sauce, Vietnamese style: equal parts of fish sauce, water, and rice vinegar or fresh lime juice (or a blend); a small amount of sugar; a little crushed garlic if you want; and a little minced chile if it pleases you. Store in a glass jar, well sealed. If you include garlic, use within three days. It’s easy to make up a fresh batch any time. Put out as a dipping sauce for meat, vegetables, spring rolls, whatever.

Another option for those who like chile heat is to keep a glass jar of fish sauce with lots of minced bird chiles in it (the small hot pointed guys also known as Thai chiles). The combo is known as nam pla prik in Thai. Delicious. The mixture is hot and salty early on, but mellows over time. As you use it, top it up with a little more fish sauce.

[Naomi Duguid is the author of six award-winning books on food and travel. Hot Sour Salty Sweet is one of the finest books ever written on Southeast Asian cuisine and a primary reason for our obsession with the region. Her latest book, Burma: Rivers of Flavor, is out in September.]