Published January 1, 2001. From Cook's Illustrated.
We required our winning brand to be both authentic and complex.
There are actually two types of oyster sauce. The first is bottled oyster sauce—called oyster-flavored sauce. The second is a cooked sauce that contains oyster-flavored sauce —think, for example, about ordering a dish such as "broccoli with oyster sauce" in a Chinese restaurant.
Bottled oyster-flavored sauce is a rich, concentrated mixture of oyster extractives, soy sauce, brine and assorted seasonings. The brown sauce is thick, salty, and strong. It is used sparingly to enhance the flavor of many dishes that have a long list of additional wet and aromatic ingredients.
Cooked oyster sauce is a mixture of various ingredients such as chicken broth, soy sauce, sake, rice wine, sherry, sesame oil, and sugar in addition to prepared oyster-flavored sauce. It is often thickened with cornstarch and tossed with a wide range of vegetables, beef, chicken, and seafood stir-fries.
Despite the fact that bottled oyster-flavored sauce is too strong to be a condiment, we thought it important to take note of each its raw, unadulterated flavor before we used it to make a cooked oyster sauce.
The potent sauce received the same standard comments—"salty," "biting," and "fishy." When we mixed the bottled oyster-flavored sauces with sherry, soy sauce, sesame oil, sugar and freshly ground pepper and made simple stir-fries, the tasters were able to detect more flavors—perhaps a result of the bottled oyster-flavored sauces, but more likely in response to the cocktail of ingredients.
The most authentic cooked oyster sauce of the group was undoubtedly that which contained our winner. Admittedly intense and somewhat fishy, it was the only sauce with true depth of flavor. Its saltiness was balanced by sweet caramel undertones and the oyster flavor was strong. This sauce, however, is not for the faint of heart. One taster proclaimed, "My American taste buds can't take it." The other bottled oyster sauce didn't seem to add much to the cooked sauces. As one taster put it, the rest "may have well been soy sauce."