Fish sauce — called nước mắm in Vietnam and nam pla in Thailand — is one of the oldest and most complex condiments in Asian gastronomy. The result of slow fermentation of fish and salt, it forms the umami backbone of an entire culinary civilisation.
A millennia-old fermentation process
Fish sauce production follows an ancestral protocol: fresh fish — anchovies or mackerel — are mixed with sea salt in precise proportions, then stacked in large wooden or cement vats. Fermentation lasts between 12 and 24 months. During this time, the fish's natural enzymes break down proteins into free amino acids, notably glutamate — responsible for umami taste — releasing an exceptional concentration of marine flavours.
How to read a label
Fish sauce quality is measured in nitrogen degrees (°N): the higher the number, the more concentrated and complex the sauce. A first-press sauce exceeds 40°N; common industrial products fall below 20°N. Also look for "first press" or "extra" on the label, indicating the sauce comes from the first natural draining of the vats, without dilution.
Culinary uses
Fish sauce is not limited to Asian cuisines. A few drops in a bolognese, stew or vinaigrette add an invisible but decisive umami depth. In Asia, it is used raw as a condiment, cooked as a sauce base, or diluted with lime, sugar and chilli to form nước chấm — the universal dipping sauce of Vietnamese cuisine.