Sauces such as oyster and fish sauce add extra flavor to dishes, and are commonly used in Chinese and other Southeast Asian-style cooking. Though these sauces originated in China, these are a staple in nearly all South Asian countries and even popular in the West.
Oyster sauce was traditionally made by concentrating oyster extract and adding other flavour additives and preservatives. Today, most oyster sauces are made with artificial flavourings, color, preservatives and corn starch to thicken the sauce.
Fish sauce can be made from different sources, depending on where it is made. It can be prepared from raw or dried fish. In some places, only a specific variety of fish is used to prepare it, whereas in others, a mix of fish is used. In order to prepare this sauce the fish is fermented in a wooden box, and then pressed slowly to obtain the fishy liquid. It is popular in both the East and West and part of many sauces and dishes.
edit Origin of oyster and fish sauce
Oyster sauce was first prepared in a province in China. Since then it has become a popular condiment used all over the world.
The origin of fish sauce is somewhat debateable. It is widely thought that this sauce originated in China. Some speculate that a type of fish sauce was also used early on in Europe, by fermenting anchovies.
edit Variations of fish and oyster sauce
Though oyster sauce was initially made by boiling oysters in water and then concentrating the extract to intensify the flavour, cheaper variations are available these days. Artificial flavors are also used to make this sauce and there is also a vegetarian version that uses mushrooms as the flavor base. Though MSG was part of the ingredient earlier, it is now avoided due to health risks.
Oyster sauce is used in chow mien, stir fries to get a Chinese flavour to the dishes. Fish sauce is used to make other sauces, and also used as a condiment, in pickles, soups, salads and casseroles.