Soy sauce is a dark, pungent thin sauce used as both a cooking and table condiment in Asian cuisine.
To make soy sauce, defatted, steamed soybeans are ground together with roasted crushed wheat. This is allowed to ferment, then salted and aged for up to a year.
Sometimes, to speed up production and make a less-expensive product, the fermenting time is reduced. To compensate for the colour not having enough time to deepen, caramel colouring is added. There are also non-fermented Soy Sauces, for which the same ingredients are steeped at a high temperature for about a day, then the sauce is filtered, coloured and adjusted for flavour. Western soy sauce is almost always made via the sped-up process.
There are dark brands and light brands, soy sauces that are made without wheat and soys that are “reduced salt”, but in North America and the UK most people would just use general purpose soy sauce.
Japan makes two versions of soy sauce. Tamari, more well known in the West, is made without wheat. The other one, Shoyu, is made with wheat.
A few drops of a good soys auce in a glass of water will start to sink down towards the bottom. A few drops of a poorer quality soy sauce will dissolve almost immediately in the water.
Depending on the brand, a tablespoon of regular soy sauce can have 900 to 1000 mg of sodium; “lite” soy sauces, 600 to 800 mg of sodium per tablespoon. In better quality reduced-sodium soy sauces, the sodium is removed after the soy sauce is brewed.
Unopened, Soy Sauce will keep on the shelf for two years. Once opened, refrigerate, or use up within a month — after that, its taste will diminish. It will still be fine for cooking up to 3 months, but not for use as a table condiment.
Low-salt Soy Sauces should always be refrigerated after opening because they have less salt to act as a preservative.
The Chinese have been making forms of Soy Sauce for millennia. In the late 8th BC, several Japanese monks who had studied in China brought the knowledge of making Soy Sauce back to Japan with them. The Japanese, as is their wont, refined and perfected the technique, and the Chinese in turn learned back from them.
Literature & Lore
Jean Anthelme Brillat-Savarin, in his book The Physiology of Taste, Dec 1825, revealed inadvertently that at the time, the French really didn’t know what Soy Sauce was made from: “There is reason to believe it [ed: the Roman sauce garum] was a foreign sauce, and was nothing else but the Indian soy, which we know to be only fish fermented with mushrooms.”
Soy sauce is sometimes also referred to as “soya sauce” in English; both usages seem to be fine, though with the passage of time, “soya” may be looking dated.