Fish sauce are made from a mixture of fish and salt that has been allowed to ferment for up to two years. Traditionally, oily fish such as anchovies are placed in a barrel with salt and slowly pressed to extract the liquid. Anchovies are often used, although some fish sauces are also made from shrimp, krill, or mackerel. The basic ingredients of a good fish sauce are fish, water, and salt. Sometimes sugars such as caramel or molasses are added, or roasted rice, but it isn't necessary.