Like wine in France or olive oil in Italy, fish sauce (nước mắm) is the prized staple of Vietnam, where it is used in soups and marinades or diluted into a sauce that accompanies foods from spring rolls to noodles.

And the best of the best, as widely agreed among Vietnamese enclaves around the world, comes from Phu Quoc, a tropical island off the nation's southwest coast. The unique taste of Phu Quoc fish sauce comes from a combination of weather, temperature and fish.

The process of making Phu Quoc fish sauce is quite simple. The two main ingredients are fresh anchovies and salt. The water 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. The vats are made from a tree indigenous to Phu Quoc and were believed to impart a special flavor to the liquid, "like oak to wine". And then salt is placed on top of them. The salt kills any bacteria that might present. Then they let the anchovy/salt mixture ferment for a period of one year. The longer the fermenting process, the nuttier the flavor.

After a period of one year, the vats are drained. The first drainage is called “first press” and this presents the highest grade of fish sauce. After that, additional salt and water are added to the vats and then the vats are drained again for a more few times.

Good fish sauce should be transparent, you should be able to see the other side of the bottle. It tastes salty at first, but the aftertaste is sweet. Fish sauce is thus a great flavor-enhancer, to give food that extra boost of flavor.