What is fish sauce? · Phu Quoc fish sauce · Protected status · How it is made · Quality · Visiting a factory · Taking it home
Phu Quoc Fish Sauce (Nước mắm Phú Quốc) is a sauce produced by fermenting black anchovies found off the coast of Phu Quoc Island in large wooden vats.
What is fish sauce?
Fish sauce, or nước mắm, is a type condiment that is composed of fermented fish and salt and has the transparency of malt vinegar and the color of amber. It is traditionally used in numerous cuisines including Thai, Philippines, Laotian,, Malaysian, Chinese, Japanese and Korean.
What is Phu Quoc Fish Sauce?
Phu Quoc Fish Sauce is a fish sauce made exclusively on Phu Quoc Island, Vietnam. This island is known to produce the highest quality fish sauce in Vietnam, if not the world. While any kind of fish can be used to make fish sauce, Phu Quoc sauce is made exclusively from anchovies caught in the waters around Phu Quoc.
Phu Quoc Fish Sauce Protected Status
The sauce from Phu Quoc is so special that in 2012 it was granted a European Union Protected Designation of Origin (PDO) status, Vietnam’s first PDO product. The PDO status means that only fish sauce, produced and bottled in the Phu Quoc Islands, can be distributed under that name.
How is Phu Quoc fish sauce made?
The process of making Phu Quoc fish sauce is quite simple. The two main ingredients are fresh anchovies (ca com) and salt. The waters around Phu Quoc have a high amount of seaweed and plankton which serves as the food source for the anchovies. The anchovies are placed in large island sourced hardwood vats shaped like gigantic round flowerpots and then salt is placed on top of them. The salt kills any bacteria that might be present. Then you let the anchovy/salt mixture ferment for a period of 6months to 1 year. The less time it spends fermenting the fishier the taste. The longer the fermentation process, the nuttier the flavor.
After a period of 1 year the vats are drained. The first drainage is called “first press” and this represents the highest grade of fish sauce. It takes about a week to fully drain one of the vats. After the first drain has finished, additional salt and water are added to the vats and then the vats are drained again. This second process is called “second press”. The process is repeated for a few more times until there is no more liquid coming out of the vats. After the vats have been drained, some producers add water, MSG, hydrolyzed wheat protein, preservatives such as sodium benzoate, and coloring to enhance the fish sauce however premium fish sauces are only made with just anchovies and salt. The left over salt and anchovy mixture is re-purposed to make flavored salt and animal feed. Nothing is wasted in the production of Phu Quoc fish sauce.
What determines the quality of fish sauce?
The quality of the sauce is determined by the following factors:
- The level of Nitrogen (“N”) in the sauce. Anything over “30N” is considered high grade fish sauce. The maximum achievable grade is 43N.
- The smell of the sauce – A good sauce will not have a strong odor to it.
- The transparency of the sauce – the sauce should not have any floating particles.
- The color of the sauce – The darker the better.
- The ingredients of the sauce – Premium fish sauce only contains anchovies and salt. No additional water, color, MSG, etc is added.
- And finally the run – The first run of the sauce, meaning the first drainage of the vats until nothing drains out anymore, is known as first run and this produces the best quality sauce.
Visiting a fish sauce factory
Several factories (nhà thùng) in and around Duong Dong let you walk among the wooden vats, smell the fermentation up close and buy straight from the source. The best-reviewed on Google Maps (October 2026):
- Huynh Khoa (Nước mắm Huỳnh Khoa), on the Duong Dong bypass — a traditional producer with a showroom, 4.9 from 387 reviews, open 7:30–17:30.
- Hong Duc (Nước mắm Hồng Đức) — 4.0 from 205 reviews, open 8:00–18:00.
- Thinh Phat — on 30 Thang 4 Street in Duong Dong, 3.9 from 279 reviews, open 7:00–18:00.
Most island tours stop at one. Visiting is free; buying is optional. Check the label for “Phú Quốc” and the protein grade (the N number) — and expect the smell to stay on your clothes for a while.
Taking fish sauce home
Fish sauce cannot go in your carry-on (liquids rules), and airlines limit it in checked baggage. Vietnam Airlines, for example, recommends checked baggage only and allows at most 3 litres or 3 kg per passenger, and does not carry it on its ATR72 flights. Use sealed plastic bottles rather than glass, and pack them in a taped box. Check your own airline’s rules before you buy — and your home country’s customs rules if you are flying abroad. More quick answers in our FAQ.
Factory ratings and hours: Google Maps, October 2026. Airline rules: Vietnam Airlines baggage page, checked October 2026.
