Fish sauce are made with anchovies, mackerel, scabbard fish and salt. The bigger the fish, the more mercury you might expect, especially if predator fish like scabbard fish. They do not have any additives like sugar, hydrolyzed protein, or preservatives. Vietnamese prefer sauces without a strong smell, and transparent with a deep golden amber color. "First press" fish sauce, meaning the sauce is bottled from the first time the fermenting barrels are drained, also indicates quality. Lastly, when measuring the nitrogen level of fish sauces (N), most fish sauce on the market falls within the mid 20N range. Anything over 30N is
Fish sauce fish sauce, called the "base". The dregs are then mixed with water and salt and again fermented for three to four months. This yields a second-grade fish sauce, mostly used in cooking. In 2014, the US Food and Drug Administration (FDA) banned the import of Thai fish sauces due to lack of information about tests for botulinum toxin. The toxin can cause death if more than 0.5 microgram is consumed. The Thai Office of Food Safety and Quality then tested 48 brands of fish sauce to determine the content of botulinum toxin in the products. Of 48 brands tested, 28