The backbone of East Asian cuisine

With its savory flavor derived from the fermentation of anchovies or similar small fish, fish sauce has formed the backbone of East Asian and Southeast Asian cuisine. However, have you ever wondered whether you prefer the rich, pungent taste of Vietnamese fish sauce or the stronger, more robust flavor of fish sauces from other countries?

"Fish sauce plays a very important role in Vietnamese cuisine: it can give a dish its character, but it can also ruin it if not used correctly," shared chef Dang Que Vinh, who recently opened a contemporary Vietnamese restaurant called "Nhau" in the heart of Hong Kong earlier this year.

"There's a huge difference between Vietnamese and Thai fish sauce. Vietnamese fish sauce is much better. I've never tried any Thai fish sauce that tastes as good as Vietnamese fish sauce," Vinh added.

Traditionally, fish sauce is made from anchovies or any other fish or shellfish too small for consumption. In the traditional method, layers of fish are alternated with layers of salt and placed in earthenware jars. Bamboo mats are used to hold the mixture in place, and heavy objects are placed on top to weigh it down. Finally, the jar is covered with a ceramic or porcelain lid and left to ferment in the warm sun for a year. As the fish begin to decompose, they release a brown liquid that settles at the bottom of the jar.

This liquid is the backbone of East Asian cuisine. In Korea it's called "aek jeot," in the Philippines "patis," while Indonesians call it "toeuk trey."

The liquid layers are distinguished by the nitrogen gas produced during fermentation. Liquid layers exceeding 30N (N stands for nitrogen content) are considered premium, 40N is considered optimal, while those exceeding 40N are considered pure. Most fish sauce sold on the market today falls within the 20N range.

Some types of Vietnamese fish sauce have the words "nhĩ" or "thượng hạng" added to their labels for easier customer identification. These terms indicate that this type of fish sauce is extracted from the top layer of fermented fish in the fermentation vats and belongs to the highest quality category.

"The top layer has a lot of essence, flavor, and is also less salty," Vinh said. This chef particularly loves the flavor of fish sauce from the Nha Trang and Phu Quoc island regions in the west of the country.

"The second layer is also very flavorful but saltier. Meanwhile, the third layer has more salt. The fourth layer is what most people know when they think of fish sauce."

Mr. Vinh doesn't use the first-grade fish sauce for cooking. He'll use the fourth-grade kind for pasta, but for dishes that require dipping sauce, it absolutely has to be the finest quality fish sauce.

Meanwhile, although Thai fish sauce isn't as elaborate and complex as Vietnamese fish sauce, it's suitable for almost all types of food – says chef Num, who runs an Isaan restaurant in Udon Thani in northeastern Thailand. "It depends on what dish the fish sauce is going to be used for," he adds.

He is currently working with local fish sauce producers in Udon Thani province to preserve the traditional method of making fish sauce. The time and effort required to make fish sauce the traditional way is vastly different from the mass-produced fish sauces sold in supermarkets today. Currently, very few people make traditional fish sauce by hand.

"One of the traditional techniques for making fish sauce is to clean the fish's internal organs, add a layer of salt, and ferment it for six months until a brown liquid rises to the surface of the fish carcasses," Num explained.

"Filter the liquid, cook it, and add some palm sugar to balance the flavor. Put them in jars and leave them in the sun to naturally kill any bacteria."

"It can be said that this is how premium nam pla (fish sauce) is made."

Hannah Nguyen