Vietnamese Fermented Foods and Agriculture: The Full Process of Nuoc Mam, Pickles, and Fermented Tea

When speaking of the Vietnamese table, fermented foods cannot be set apart.
Their distinctive flavor and deep umami are the crystallization of many years of agriculture and traditional technique.

"How is nuoc mam made?" "How do Vietnam's fermented foods differ from Japan's?"
Many people have such questions.

This article explains in detail Vietnam's three major fermented foods, nuoc mam, traditional pickles, and fermented tea, from the raw-material produce to the production process. It is useful content for agricultural professionals, food importers, and anyone interested in Vietnamese business.

What Is Nuoc Mam (Fish Sauce)? Its Deep Connection to Vietnamese Agriculture

Nuoc mam is a Vietnamese fermented seasoning made from only fish and salt.
It is the equivalent of Japan's soy sauce and is used in almost all home cooking.
Annual production is estimated to exceed 300 million liters, and it is exported actively, not just consumed domestically.

The main raw-material fish is a small fish of the anchovy genus, called "ca com" in Vietnamese.
Phu Quoc Island and the Phan Thiet coast are famous as production areas.
These fisheries and salt-field farming support the foundation of the nuoc mam industry.

Production Areas of the Salt Used as a Raw Material

The salt used for nuoc mam differs in quality from ordinary table salt.
Coarse salt sun-dried in the salt fields of Khanh Hoa and Ninh Thuan Provinces is preferred.
It is rich in minerals and is said to have a favorable effect on the fermentation process.

A Thorough Explanation of the Nuoc Mam Production Process

Step 1: Sorting and Mixing the Raw Materials

Fresh small fish are rinsed with water and mixed with salt, entrails and all.
The ratio of fish to salt is roughly 3 to 1 as a base.
This ratio greatly influences the fermentation speed and the final flavor.

Step 2: Charging the Fermentation Tanks

The mixed raw materials are packed into large wooden or ceramic tanks.
Coarse salt is laid at the bottom of the tank, and the top is also covered with salt.
This suppresses the growth of unwanted bacteria while promoting beneficial enzyme reactions.

Step 3: Long-Term Aging (12 to 24 Months)

The fermentation and aging period is at least 12 months, and high-quality products take 24 months or more.
During aging, the tank is opened periodically and the liquid is circulated, a task repeated again and again.
This "stirring of the nuoc noi (the floating liquid)" is an important step that produces richness and umami.

Step 4: Filtering and Shipping

After aging is complete, it is filtered with bamboo or cloth to remove impurities.
The first liquid extracted (the first pressing) is considered the highest quality.
The grade is determined by the nitrogen content (derived from protein).

Vietnam's Traditional Pickles and Their Produce Ingredients

Vietnam has a diverse pickle culture that varies by region.
What differs from Japanese pickles is the short fermentation period and the use of chili and herbs.
It is a food culture combining agricultural production and fermentation technique.

Representative Pickles and the Produce Used

The produce used for pickles is in most cases supplied by small local farmers.
Home gardens and small farm plots play a more important role than large-scale farms.
Stable supply to food manufacturers is a challenge, and the introduction of contract farming is advancing.

Rice and Sugarcane That Aid Fermentation

Vietnamese pickles sometimes use rice or sugar as a fermentation promoter.
In the south in particular, raw sugar derived from sugarcane is added to adjust sweetness and fermentation speed.
This is another example of Vietnamese agriculture supporting fermented foods.

Vietnam's Fermented Tea (Pu-erh Type and Aged Tea)

It is not widely known, but Vietnam has its own fermented-tea culture.
In the northern mountains (Ha Giang and Lai Chau Provinces), production of post-fermented tea continues.
The fermented tea traditionally produced by ethnic minorities has drawn attention in recent years as a premium product.

The Raw-Material Agriculture for Fermented Tea

Vietnam's tea cultivation is carried out mainly in mountainous areas at 500 to 1,500 m elevation.
The representative variety is a native type called "cha tan" (Shan Tuyet), and there are also old trees over 100 years in age.
organic cultivation A distinctive feature is their high proportion, with many of the farms growing without agrochemicals.

The production process of fermented tea

1. Plucking: hand-picking the buds and young leaves
2. Withering: driving off moisture in the sun or indoors
3. Fixing (pan-firing): deactivating the oxidizing enzymes by roasting or steaming
4. Rolling: rolling the leaves to shape them and break down the cells
5. Pile fermentation: microbial fermentation in a humidity- and temperature-controlled environment (7 to 30 days)
6. Drying, pressing, and shaping: shaped into discs or bricks for shipment

The microbes at work during fermentation are molds of the genus Aspergillus and lactic acid bacteria.
These break down the astringency of the tea leaves and create a mellow flavor.

Potential in the Japanese market

In Japan, fermented tea generally means pu-erh tea (from China).
But Vietnamese fermented tea is price-competitive and has a rich terroir (regional character).
There is room to enter the health-food and premium-beverage markets.

Comparing Japanese and Vietnamese fermented foods

In both Japan and Vietnam, fermented foods sit at the heart of the food culture.
Differences in the source crops, climate, and microbes create the differences in taste.

For Japanese food importers, Vietnamese fermented foods are a market worth watching.
Nuoc mam already has an import track record, but pickles and fermented tea remain largely untapped.

Summary

Vietnam's fermented foods are a deep culture in which agriculture and microbial technology come together.

• nuoc mam (fish sauce): long aging of small fish and salt, supported by coastal fishing and salt-field production
• Traditional pickles: short fermentation of local produce, with diverse varieties and methods across the north and south
• Fermented tea: post-fermented tea made from native tea leaves of the northern mountains, with potential in the Japanese market

Business opportunities through the fermented-food industry will keep expanding in the years ahead.
Deepening your understanding of the source agriculture leads to building a sustainable supply chain.

At VN AGRI, we share the latest information on Vietnamese agriculture.

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