It is a condiment that is made from fermenting fish. Tt is most commonly used in Asian cuisine. It is amber colored and liquid-like. Fish sauce is generally salty in taste and has a pungent smell but its taste slightly alters in different countries. In china, it is said to be very salty and mostly suitable for cooking but in Vietnam you will find a slightly sweetened version and the smell is also less pungent.
The main ingredients are fish extracts and salt along with a few spices. It can be made out of fresh, dried, salt-cured or cooked fish. Anchovies is the most common choice for fish sauce. For the fermentation process, fish and salt are kept in a wooden box and then pressed to take out the liquid. This process alters in different parts of the world.
In southeast Asian cuisines, fish sauce is used as a cooking sauce and many a times it is used like a dipping sauce. Fish sauce is very common in Thai meals as almost every Thai cuisine is served with a condiment made out of fish sauce. In western cuisines, fish sauce is not made from fermented fish, packaged or fresh fish is used.
The origin of fish sauce is not certain, though its earliest use is known to be as Garum in Roman cooking, it was made from anchovies and assorted fish. It is said that the Romanians also used Garum as a medicine to cure dog bites, ulcers and relief from diarrhea and constipation. It was also used as a cosmetic to remove freckles.