Fish Sauce, the Vietnamese Miracle Sauce Made from Fermented Fish

Nước mắm (pronounced /nɥɔk mam/) is the famous Vietnamese fish sauce made from fermented fish, and it is an integral part of the local cuisine. Recognized by its dark color and unique, powerful, and pungent smell, it can be quite overwhelming for the unprepared nose. Used as a condiment, the Vietnamese commonly mix nước mắm with other ingredients such as water, lime, garlic, sugar, or chili. Discover all the secrets of this star sauce of Vietnam, a must-try during your trip to Vietnam!

Written by Jade NGUYEN, (local expert) Updated on 14-05-2025

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Table of contents

1. How is Nước Mắm, the famous Vietnamese fish sauce, made?
2. Where to find the best fish sauces in Vietnam?
3. Easy Vietnamese Fish Sauce Recipes
4. Buying Nước Mắm

1. How is Nước Mắm, the famous Vietnamese fish sauce, made?

Nước mắm, the fermented fish sauce, is made by pressing fish that has been fermented with salt. The authentic nước mắm is made exclusively from anchovies, although in some regions, other types of fish are added. Vietnamese fishermen go on multi-day fishing trips to supply anchovies to nước mắm makers.

The anchovies are stored in large barrels or jars, with the type of wood carefully selected, as it imparts a unique color to the brine produced after at least one year of fermentation. On Phu Quoc Island, laurel wood is used, as it grows abundantly there.

To produce excellent brine, the ratio of 1:3 is strictly followed, with one part salt to three parts anchovies. The first brine is extracted after a few months and is poured back into the barrel, a process repeated throughout the production of this famous fish sauce.

The first few liters, called "nuoc mam nhi," are considered the best, much like the first press of olive oil. This syrupy first extract is a true nectar. Over time, the sauce, initially very dark, begins to lighten, and its strong flavor gradually mellows.

Nước mắm, widely used in Vietnamese cooking, is also a health asset. It's packed with proteins, amino acids, and numerous minerals that support bone and blood formation. It also provides a significant amount of iron, copper, and vitamins, especially B12, which is crucial for brain and nervous system function.

*Anchovies are used to make the best nuoc mam*

2. Where to find the best fish sauces in Vietnam?

Nước mắm is produced along the Vietnamese coastline, but three places are renowned for producing the best fish sauce made exclusively from anchovies.

2.1 Phu Quoc Island

The best fish sauce in Vietnam undoubtedly comes from Phu Quoc Island. This island paradise, located at the southernmost tip of the country, is loved by travelers for its crystal-clear waters and dream beaches. It is home to hundreds of artisanal fish sauce factories, producing nearly 10 million liters per year. The excellence of Phu Quoc fish sauce comes from using only one type of anchovy.

Phu Quoc fish sauce producers swear by the long-jawed anchovy, which is plump and can grow up to 26 centimeters long. When visiting Phu Quoc Island, don't miss the chance to tour one of the fish sauce factories to witness the process of making this famous Vietnamese sauce and see the massive barrels where the anchovies are fermented.

Phu Quoc fish sauce is the only one in Vietnam with a Protected Geographical Indication (PGI) and is the first Vietnamese product to receive a Protected Designation of Origin (PDO) from the European Union. Phu Quoc fish sauce is exported worldwide, making it a true star of Vietnamese fish sauce!

>>> Read also: Things to do and see in Phu Quoc

2.2 Phan Thiet

Located about 200 kilometers northeast of Saigon, near the resort town of Mui Ne, Phan Thiet has been producing fish sauce since the early 19th century. As a veteran in fish sauce production, Phan Thiet opened the country's first fish sauce museum in April 2018.

The Phan Thiet Fish Sauce Museum offers several spaces, including a cinema with a large screen that tells the story of ancient fishing villages, a cultural area showcasing the ancient Champa Kingdom, and an exhibition space with paintings and photos of past activities in this coastal region. In one corner, you can see the barrels used to make fish sauce and learn about the traditional production process.

*The production of nuoc mam on Phan Thiet*

2.3 Nha Trang

The famous resort town of Nha Trang, located in central Vietnam, is the third major location for high-quality fish sauce production. Nha Trang produces some of the best fish sauce in Vietnam, exclusively from anchovies caught in one of the most beautiful bays in the world. You can also visit one of the many fish sauce factories in Nha Trang to learn about the production secrets.

>>>> Learn more about: Is Nha Trang Worth Visiting?

3. Easy Vietnamese Fish Sauce Recipes

Similar to how salt is used in other cuisines, nước mắm is a common ingredient on the dining table and is used in the majority of Vietnamese recipes. It needs to be taken with caution due to its strong flavor and high salt content. Lime, sugar, garlic, chile, ginger, shrimp paste, unsalted roasted peanuts, coriander, mint, and even olive oil go well with it.

*Nuoc mam is used in most Vietnamese culinary preparations*

When combined with other ingredients, nước mắm goes well with a variety of foods, including meats, vegetables, seafood, and stir-fried, raw, steamed, and boiled foods. Usually, it's used as a dipping sauce for foods like Vietnamese nems, spring rolls, and banh xeo, which are crispy pancakes from Vietnam. The renowned bun cha's pork pieces and meatballs are dunked in a nước mắm sauce. In stews like the tasty caramelized pork, a few drops of nước mắm are also added.

Let's now demonstrate how to prepare Vietnamese-style fish sauce at home. After that, you can dip your bun cha, banh xeo, or nems and savor it! It's a quick and simple recipe.

3.1 Fish sauce for Nems

In a bowl, mix the following ingredients:

4 tablespoons of nước mắm (preferably Phu Quoc)
2 teaspoons of freshly squeezed lime juice
2 teaspoons of sugar
About 300 ml of water

Heat the mixture until the sugar dissolves. Let it cool. Add minced garlic and sliced chili. You can also add thin slices of carrot and cucumber for extra crunch. This sauce can be stored in the fridge for up to 2 weeks.

>>> Learn more about: Vietnamese spring rolls

3.2 Fish sauce for Bún Chả

Peel and finely chop green papaya and carrot.
In a large bowl, mix:
- 6 tablespoons of rice vinegar
- 6 tablespoons of nước mắm
- 12 tablespoons of water
Add 3 tablespoons of sugar (adjust to taste).
Once the sauce is ready, add:
- 1 finely chopped garlic clove
- A bit of red chili
Add the chopped carrot and papaya to the mixture.

4. Buying Nước Mắm

When buying nước mắm, make sure to read the label carefully and ensure that it contains only salt and anchovies. Avoid sauces with additives or monosodium glutamate (MSG). Visit an Asian grocery store, as they tend to carry better products than regular supermarkets.

If you want to buy excellent nước mắm, make sure to get the "nước mắm nhi," which is the first press, and ensure it comes from Phu Quoc Island, where it is considered the best. Look for a fish sauce with a high concentration of nitrogen (proteins). On the bottles, you'll find a number in degrees. It's recommended to choose one with a 40°N concentration and not go below 30°N.

The "nước mắm nhĩ" from Phu Quoc has a beautiful amber color and a much less aggressive scent than lower-quality fish sauces. Be cautious of counterfeit fish sauces that illegally label themselves as Phu Quoc products. The best way is to buy it directly from the factory during your next trip to Vietnam!