Oyster (Flavored) Sauce（蚝油/蠔油）

Oyster sauce describes a number of sauces made by cooking oysters. The most common in modern use is a viscous dark brown condiment made from sugar, salt and water thickened with cornstarch, flavoured with a little oyster essence or extract and some versions may be darkened with caramel, though high quality oyster sauce is naturally dark. It is commonly used in Cantonese, Vietnamese and Khmer cuisine.

The development of oyster sauce is often credited to Lee Kam Sheung, from Nam Shui Village, Guangdong. Lee made his living running a small eatery that sold cooked oysters. One day, he was cooking oysters as usual, but lost track of time until he smelt a strong aroma. Lifting the lid of the pot, he noticed that the normally clear oyster soup had turned into a thick, brownish sauce. He started to sell this new invention which turned out to be very popular. So in 1888, he formed Lee Kum Kee Oyster Sauce House to mass produce oyster sauce.

However, there are lesser names in the world of oyster sauce making which claim to have an earlier start; for instance, Macau's 榮生 of 1868 is just one example that still exists today. Many insiders believe that oyster sauce may well have existed for over a thousand years.

"True" oyster sauce of good quality should be made by condensing oyster extracts, the white broth produced by boiling oysters in water. This opaque broth, similar to the color of clam juice found in supermarkets, is then reduced until a desired viscosity has been reached and the liquid has caramelized to a brown colour. No other additives, not even salt, should be added to the sauce, since the oysters should provide all the savory flavour. However, this method is cost prohibitive.
Many modern oyster sauces are thickened with cornstarch, flavoured with oyster essence or extract and darkened with caramel.

Oyster sauce adds a savory flavor to many dishes, making it an ideal choice for flavoring meat and vegetables. The sauce is a staple for much Chinese family-style cooking. It is commonly used in noodle stir-fries, such as chow mein. It is also found in popular Chinese-American dishes such as beef with stir-fried vegetables. Oyster sauce can also be used as a topping for some dishes. (For examples see Kai-lan, Buddha's delight, Hainanese chicken rice, Cashew chicken, Lo mein, Cha siu baau, Yum cha, Har gow, Kai yat sai, Wonton noodles, and Daikon cake. For further information see Thai cuisine, Hmong cuisine, cuisine of Cambodia, Cantonese cuisine, Cuisine of Hong Kong, and American Chinese cuisine).