Le Hai Dang
Former Head of the Cultural Heritage Department,
Vietnam National Institute of Culture and Arts Studies (VICAS), Ho Chi Minh City

Vietnam is a country with a coastline stretching over 3,260 km. It is perhaps no surprise, then, that the country has seen versatile maritime cultures flourish. Fisheries, marine product processing, fish sauce production, shipbuilding (including fishing net manufacturing), and maritime freight services, among others, are major sources of employment in Vietnam, while the abundance of fishing grounds in the seas all around the country has resulted in fishing villages as well as coastal cities and provinces springing up in their vicinity.
Nước mắm (Nuoc mam), or fish sauce, is both a seasoning and condiment that is popular and ubiquitous in the culinary culture of Vietnam. It is used not only as a dipping sauce but also as a processed seasoning to add flavor to dishes. Nước mắm production has a long history in Vietnam, influenced by the country’s thriving maritime culture. In the past, at times when Vietnam had an abundance and even an excess of fishing yields, Vietnamese people took advantage of the plentiful bounty by processing seafood products for long-term storage, primarily through natural fermentation, drying catch such as squid and fish, or making fish sauce such as nước mắm from a variety of species.
Nước mắm production has developed across many regions of Vietnam, primarily in the provinces of Quang Ninh, Khanh Hoa, and Ninh Thuan, as well as areas of Cat Hai, Hai Phong, Cai Rong, Nha Trang, and Ca Na. In particular, Phan Thiet, Phu Quoc, and the provinces of Kien Giang and Binh Thuan are renowned fish sauce producers.
The two essential ingredients in making nước mắm are no more than fish and salt. The most widely used fish for producing nước mắm are amberstripe scad, anchovy, sardine, snapper, herring, and yellow jack, which yield different types of sauce. Amberstripe scads produce dark-brown nước mắm with a high protein content, anchovies produce light-yellowish nước mắm with a delicate fragrance, while yellow jacks produce bright yellow nước mắm after it filtering over a very long period using a traditional method. Among the different types, nước mắm made with ca danh (Puntioplites falcifer, a freshwater species of Cypriniformes found across the Mekong Basin in Southeast Asia) has traditionally been the most prized fish sauce, almost exclusively served for fishermen’s home meals and difficult to find in markets.
In the traditional method for making nước mắm, the following hygienic tools and adequate containers must first be prepared: boxes (or wooden barrels); a bucket or basket with a large, shallow, concave shape, with stones placed on the covering to ensure that all fish remain submerged; large bamboo-woven coverings to restrict air passage; ladles; long wooden sticks for stirring; a deep, hollow basket; and a ladder for working around the barrel. Then, the lu, a filter used to obstruct the passage of residue in the sauce-making process, is prepared, and a spigot is installed adjacent to the bottom of the barrel. Also, salt and chaff is mixed before salting the fish to purify the mixture, and then the outside is blocked or pressed using a broomstick-shaped brush before the fish is poured into the barrel. This spigot is used to drain the nước mắm upon opening.

Making Nước Mắm
Nước mắm is made using a three-stage process, which is described below. It typically takes from about six months to one year from salting the fish to the production of perfect nước mắm.

Stage 1: Chượp cá (Chuop ca, A series of processes for salting and pressing the fish and fish meat protein decomposition)
In the first stage, the fish sauce maker mixes the fish and salt at a certain ratio. For instance, amberstripe scad (Carangidae) requires a fish-to-salt ratio of 4:1 while Cyprinidae and many other species require a ratio of 6:1. The fish sauce maker pours and layers the fish in the barrel, piling the fish in one layer and then salt in another. Then, the maker places the vi, a large bamboo-woven covering to restrict airflow, and closes the lid. After several days, the maker decants the mixture by draining the liquid fish extract from the barrel by opening the spigot to pour out the initial salty water used to brine the unfermented fish.

Stage 2: Management
The next stage entails mixing the fish and salt, fermentation, and the final process of long. The process long refers to opening the spigot and pouring the liquid fish extract into another barrel, and mixing it. This process is repeated several times in order to obtain the optimal density.

Stage 3: Drain
The fish sauce maker removes the large inlet and lets the nước mắm trickle out through the small inlet on the barrel.

Traditional Culinary Heritage
Any Vietnamese-style dipping sauce is commonly referred to as nước mắm, while others regard nước mắm as simply one of many dipping sauces. However, culinary experts believe the value of nước mắm to be wholly different from that of typical dips, and assert that, in terms of ingredients and techniques, nước mắm constitutes a unique condiment and flavor created using fish, salt, and natural fermentation process.
Nước mắm is almost a dish in itself, as it is a constant mainstay of Vietnamese meals. In other words, nước mắm represents Vietnamese traditional culinary heritage and embodies the identity of the Vietnamese people, characterized by the custom of sharing a bowl of fish sauce with others around the dining table—everybody shares the sauce, regardless of age or gender, or whether they are relatives, friends, or regular guests. As such, the unique characteristics and flavor of nước mắm represent various aspects of traditional Vietnamese culture.
In this regard, nước mắm has served as not only as a treasure trove of folk knowledge, including longstanding wisdoms and lived experiences, but also as a vessel to mutually communicate feelings and sentiments within communities. A shared bowl of nước mắm at a daily meal simply represents a shared love in cohesion and solidarity among community members.