Oyster sauce is a thick brown sauce made from oysters, brine, umami flavor enhancers likes MSG and preservatives.

Invented in 1888 in China, oyster sauce is commonly used in Chinese (especially Cantonese), Filipino and Thai cooking. It is popular on steamed vegetables such as broccoli or in stir-fried dishes.

No salt is added to a good-quality oyster sauce, which gets its salty brininess from the oysters, which are simmered until they produce a broth that is then cooked down until thick and caramelized. Inferior oyster sauces may thicken the sauce with starch and caramel coloring.