To avoid having to repeat this information in each recipe, I thought I'd do a post on soy sauce basics that I can refer to elsewhere. I'm familiar with Chinese soy sauce and to a lesser extent some of the Thai variants. I invite others to post info here on soy sauce variants from Japan, Korea, Vietnam, and elsewhere.
Soy sauce is made from soy beans ground up and fermented with flour, water, and salt. Sometimes other ingredients (mushrooms, sugar) are added. Oxidation and fermentation give it a brownish color and distinctive aroma and flavor. This is authentic or naturally-brewed soy sauce. There is also artificial soy sauce that is made from soy bean extract. It has none of the fine aroma and flavor of naturally-brewed soy sauce and should be avoided. Up until the 1970s only the artificial kind was widely available in US supermarkets, mainly under the brand names Chun King and La Choy. Then Kikkoman, a naturally-brewed soy sauce from Japan, came on the scene. Kikkoman is now available almost everywhere in the US. The soy sauce in sachets commonly packed with take-out from US Chinese restaurants is, alas, usually the artificial stuff.
Chinese soy sauce
There are four major types of Chinese soy sauce:
Light soy sauce. This is sometimes called "thin soy sauce". It is "light" in color, versus dark soy sauce, and thinner in texture. Do not confuse it with "lite"--meaning reduced sodium--soy sauce, which is light soy sauce made with less salt. Light soy sauce is generally used in stir-fries, especially with chicken, shrimp, and lighter colored vegetables where you don't want the other ingredients stained brown. It's very popular in East Coast provinces and cities such as Guangdong (Canton) and Shanghai. Kikkoman from Japan is the easiest to find light soy sauce in the US. I personally prefer Pearl River Bridge brand from China.
Dark soy sauce. This has a bit of sugar or molasses added, which gives it a darker color, thicker texture, and more forceful flavor than light soy sauce. It is the preferred soy sauce for red-cooked dishes. It's also used, sometimes in combination with light soy sauce, in stir-fries of darker colored meats such as beef and lamb. It's used a lot in Sichuan.
Mushroom soy sauce. This is light soy sauce with added mushrooms or mushroom extract. It's used to impart a mushroom character to the dish. It's used far less commonly than light or dark soy sauce. I've only seen it called for in a few steamed dishes. I've added some to stir-fries or to red-cooked dishes when I want a touch of mushroom flavor.
Black soy sauce or thick soy sauce. This is molasses with added soy sauce and salt and has the consistency of molasses or treacle and a strong molasses aroma. It comes in jars rather than bottles. Its main use is to give a brown color to Cantonese fried rice. I've sometimes added it to red-cooked dishes where I want a more forceful flavor and color. Koon Chun is the most common brand I've seen. Gravy Master or Kitchen Bouquet can be used as substitutes.
Thai soy sauce
Light, dark, and mushroom soy sauce are also used in Thai cooking, especially light soy sauce. There are also a couple of varieties, less commonly called for, that are not found in China:
Black soy sauce. Thai black soy sauce is also molasses with added soy sauce, but it's a lot thinner than its Chinese counterpart and comes in bottles rather than jars. It can be used in stir-fried rice dishes and also as a dip for dumplings.
Sweet soy sauce. This is a syrup of brown and refined sugar with light soy sauce added. It's used mainly as a table condiment with roasted meats or with dumplings.
-Paul W.
