Fish sauce (nuoc mam) is to Vietnamese cooking what salt is to Western and soy sauce to Chinese cooking. It is included in practically all recipes. Prepared from fresh anchovies and salt, layered in huge wooden barrels, the manufacture of fish sauce is a major industry. The factories are located along the coast to assure the freshness of the fish to be processed. Fermentation is started once a year, during the fishing season. After about 3 months in the barrel, liquid drips from an open spigot, to be poured back into the top of the barrel. After about 6 months the fish sauce is produced.

The first draining is the very best fish sauce, lighter in color and perfectly clear. [Kinda like "Extra Virgin" fish sauce.] It is relatively expensive and is reserved for table use. The second and third draining yield a fish sauce of lower quality and lower cost for general- purpose cooking. The two towns most noted for their fish sauce are Phu Quoc and Phan Thiet. Phu Quoc produces the best fish sauce, some of which is exported. On the label, the "nhi" signifies the highest quality. If fish sauce manufactured in Vietnam is not available when cooking Vietnamese dishes, that of Thailand (nam pla) or Hong Kong is acceptable. Philippine (patis) or Chinese fish sauce will not be satisfactory.

To make your own mock fish sauce:

1. Simmer for 10 minutes a mixture of 1 can drained anchovies + 2 cloves bruised and peeled garlic + ½ teaspoon brown sugar + ¼ teaspoon salt + 1 ¼ cups water, then strain. (Adapted from a recipe in the All Around the World Cookbook by Sheila Lukins.) OR
   
2. Simmer for 10 minutes a mixture of 1 part soy sauce + 4 parts anchovies (Adapted from a recipe in Substituting Ingredients by Becky Sue Epstein and Hilary Dole Klein.) OR
   
3. Soak anchovies from one small can (about 14 fillets) in 1 cup water, strain, then add 2 tablespoons soy sauce.