famous for producing fish sauce: Phú Quốc and Phan Thiết. Fish sauce has a 300 year history dating back to the Champa kingdom of the Cham people. The birthplace of fish sauce is believed to be from Phan Thiết. Phan Thiết can be identified with Vietnamese fish sauce. Before 1693, Phan Thiết was a territory of Champa. The Vietnamese arrived in the area and commercialized the fish sauce by keeping it in barrels and selling throughout the country. This business was popularized by Trần Gia Hòa who was born in 1872. There is a fish sauce museum in Phan Thiết. Popular brands in the US include Mega Chef, Red Boat, 3 Crabs, Golden Boy, and Hòn Phan Thiết. Vietnamese fish sauces are made with anchovies, mackerel, scabbard fish, and salt. High mercury concentration can be found in larger fish, especially in 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 considered high-grade, and 40N is optimal. Nước chấm is a Vietnamese prepared fish-based condiment (also referred to as a "sauce") that is savory, lightly sweet and salty tasting, and can be sour and spicy if lime and chili peppers are added. The main components are fish sauce, water, and sugar. Mắm is made much like fish sauce, except that it is not fermented as long, and the fish is kept along with its liquid extract, not just the extract. Mắm can be used as a base condiment in dipping sauces with additional ingredients or used in soups or stir-fries. In January 2016, the Institute of Food Technologists published a study asserting that using Vietnamese fish sauce as a substitute for sodium chloride (salt) in chicken broth, tomato sauce, and coconut curry reduced the amount of sodium chloride by 10 to 25 percent while still maintaining the perceived deliciousness, saltiness, and overall flavor intensity. East Asia China In China, fish sauce is called yúlù (, literally "fish dew") and is native to the provinces of Guangdong and Fujian. In Chaoshan cuisine,