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 In January 2016, the Institute of Food Technologists published a study asserting that the "Vietnamese fish sauce added to chicken broth, tomato sauce and coconut curry reduced the amount of sodium chloride by 10-25 percent while still maintaining the perceived deliciousness, saltiness and overall flavor intensity." In China, fish sauce is called "yúlù" (, literally "fish dew") and is native to the provinces of Guangdong and Fujian. In Japan, fish sauce variations are used as a seasoning of local specialties. "Ishiru" in the Noto Peninsula is made from sardine and squid. "Shottsuru" of Akita Prefecture is mainly made from sailfin