Fish sauce is often made from anchovies, salt, and water, and is intensely flavoured. Anchovies and salt are arranged in wooden barrels to ferment and are slowly pressed, yielding the salty, fishy liquid. The salt extracts the liquid via osmosis. Southeast Asians generally use fish sauce as a cooking sauce. However, there is a sweet and sour version of this sauce which is used more commonly as a dipping sauce (see "nước chấm"). Fish sauce in Burma is called "ngan bya yay" (ငံပြာရည်). In Cambodia, fish sauce is known as "teuk trei" (ទឹកត្រី), of which there are a variety of sauces using
Fish sauce 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. "Nước 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.