Oyster Sauce

Oyster sauce arrived with Chinese cooks and became a fixture of Thai stir-frying. It is thick and glossy, sweet and savoury at once, and it gives a stir-fry a sauce that clings to every piece.

What it is

Traditionally, oyster sauce was made by slowly simmering oysters in water until the liquid reduced to a thick, brown extract. Today most oyster sauce is made from oyster extract cooked with sugar, salt and cornflour, with colouring and flavour enhancers in cheaper brands. It does not taste fishy; it tastes savoury and slightly sweet.

How to cook with it

Thai stir-fries usually combine it with light soy sauce, fish sauce and a little sugar: oyster sauce for body and gloss, soy for saltiness, fish sauce for depth. A tablespoon is plenty for two portions.

It is essential in pad kra pao, phak boong fai daeng (stir-fried morning glory), pad pak ruam (mixed vegetable stir-fry), pad see ew and stir-fried Chinese kale with crispy pork. It is also good in marinades for grilled pork and chicken.

Add it in the last minute of cooking, so the sugar in it does not burn on the hot wok.

Choosing a good one

Read the ingredient list: the higher up oyster extract appears, the better. Thai brands such as Maekrua (Mae Krua) are well liked by Thai cooks; Lee Kum Kee Premium is widely available and good.

Storing

Refrigerate after opening. It keeps for months, but check for mould on the neck of the bottle if it has been open a long time.

Substitutes

Vegetarian “oyster” sauce made from shiitake mushrooms is widely available and works almost identically. Otherwise, use soy sauce with a little sugar and a pinch of cornflour to thicken.

Cook’s tip

Mix your stir-fry sauce in a small bowl before you start cooking. Thai stir-fries take two or three minutes, and there is no time to open bottles once the wok is hot.