Soy sauce or soya sauce, is a condiment traditionally made from a fermented paste of cooked soybeans, roasted grain, brine, and an Aspergillus mold. After fermentation, the paste is pressed, producing a liquid, which is the soy sauce, and a solid byproduct, which is often used as animal feed. Lesser quality soy sauces aren’t fermented and are instead made from acid-hydrolyzed soy protein. Soy sauce is a traditional ingredient in East and Southeast Asian cuisines, where it is used in cooking and as a condiment. It originated in China in the 2nd century BCE and spread throughout Asia.
Soy sauce has a distinct yet basic taste of umami, due to naturally occurring free glutamates.
Most varieties of soy sauce are salty, earthy, brownish liquids intended to season food while cooking or at the table. Many kinds of soy sauce are made in China, Taiwan, Japan, Korea, Indonesia, Vietnam, Burma and other countries. Variation is usually achieved as the result of different methods and durations of fermentation, different ratios of water, salt, and fermented soy, or through the addition of other ingredients.
Soy sauce originated in China sometime between the 3rd and 5th century from an older meat-based fermented sauce named jiang. Its use later spread to East and Southeast Asia. Like many salty condiments, soy sauce was probably originally a way to stretch salt, historically an expensive commodity. In ancient China, fermented fish with salt was used as a condiment in which soybeans were included during the fermentation process. Eventually, this was replaced and the recipe for soy sauce, jiangyou, using soybeans as principal ingredient, with fermented fish-based sauces developing separately into fish sauce.
Records of the Dutch East India Company list soy sauce as a commodity in 1737, when seventy-five large barrels were shipped from Dejima, Japan, to Batavia (present-day Jakarta) on the island of Java. Thirty-five barrels from that shipment were then shipped to the Netherlands. In the 18th century, Isaac Titsingh published accounts of brewing soy sauce. Although earlier descriptions of soy sauce had been disseminated in the West, this was among the earliest to focus specifically on the brewing of the Japanese version. By the mid-19th century, the Japanese soy sauce gradually disappeared from the European market, and soy sauce became synonymous with the Chinese product. Europeans were unable to make soy sauce because they did not understand the function of Aspergillus oryzae, the fungus used in its brewing.
Chinese Soy Sauce
Chinese soy sauces are primarily made from soybeans, with relatively low amounts of other grains. Chinese soy sauce can be roughly split into two classes which can be brewed or blended.
Brewed
Soy sauces that have been brewed directly from a fermentation process using wheat, soybeans, salt, and water without additional additives.
Light soy sauce is a thin, opaque, lighter brown soy sauce, brewed by first culturing steamed wheat and soybeans with Aspergillus, and then letting the mixture ferment in brine. It is the main soy sauce used for seasoning, since it is saltier, has less noticeable color, and also adds a distinct flavor. (“Light” refers to the paler color and not a lower sodium content, as in a “Lite” soy sauce.)
Tóuchōu is light soy sauce made from the first pressing of the soybeans, which can be loosely translated as first soy sauce or referred to as premium light soy sauce. Tóuchōu is sold at a premium because, like extra virgin olive oil, the flavor of the first pressing is considered superior. Due to its delicate flavor it is used primarily for seasoning light dishes and for dipping.
Shuānghuáng/Seong wong is a light soy sauce that is double-fermented by using the light soy sauce from another batch to take the place of brine for a second brewing. This adds further complexity to the flavor of the light soy sauce. Due to its complex flavor this soy sauce is used primarily for dipping.
Yìnyóu/Yaam yau is a darker soy sauce brewed primarily in Taiwan by culturing only steamed soybeans with Aspergillus and mixing the cultured soybeans with coarse rock salt before undergoing prolonged dry fermentation. The flavor of this soy sauce is complex and rich and is used for dipping or in red cooking.
Blended
Additives with sweet or umami (savory) tastes are sometimes added to a finished brewed soy sauce to modify its taste and texture.
Dark soy sauce is a darker and slightly thicker soy sauce made from light soy sauce. This soy sauce is made through prolonged aging and may contain added caramel color and/or molasses to give it its distinctive appearance. This variety is mainly used during cooking, since its flavor develops during heating. It has a richer, slightly sweeter, and less salty flavor than light soy sauce. Dark soy sauce is partly used to add color and flavor to a dish after cooking, but, as stated above, is more often used during the cooking process, rather than after.
Mushroom dark soy sauce is made by adding broth from Volvariella volvacea mushrooms during finishing and aging, then exposing the sauce to the sun. The added broth gives this soy sauce a richer flavor than plain dark soy sauce.
Thick soy sauce is a dark soy sauce that has been thickened with starch and sugar and occasionally flavored with certain spices and MSG. This sauce is often used as a dipping sauce or finishing sauce and poured on food as a flavorful addition, however due to its sweetness and caramelized flavors from its production process the sauce is also used in red cooking.
Japanese Soy Sauce
Buddhist monks from China introduced soy sauce into Japan in the 7th century, where it is known as shōyu.
Shōyu is traditionally divided into five main categories depending on differences in their ingredients and method of production. Most, but not all Japanese soy sauces include wheat as a primary ingredient, which tends to give them a slightly sweeter taste than their Chinese counterparts. They also tend towards an alcoholic sherry-like flavor, sometimes enhanced by the addition of small amounts of alcohol as a natural preservative. The widely varying flavors of these soy sauces are not always interchangeable, some recipes only call for one type or the other, much like a white wine cannot replace a red’s flavor or beef stock does not make the same results as fish stock. Some soy sauces made in the Japanese way or styled after them contain about fifty percent wheat.
Koikuchi originated in the Kantō region, its usage eventually spread all over Japan. Over 80% of the Japanese domestic soy sauce production is of koikuchi, and can be considered the typical Japanese soy sauce. It is made from roughly equal quantities of soybean and wheat.
Tamari is made mainly in the Chūbu region of Japan. Tamari is darker in appearance and richer in flavor than koikuchi. It contains little or no wheat. Wheat-free tamari can be used by people with gluten intolerance. It is the “original” Japanese soy sauce, as its recipe is closest to the soy sauce originally introduced to Japan from China. Technically, this variety is known as miso-damari, as this is the liquid that runs off miso as it matures.
Shiro, in contrast to tamari soy sauce, uses mostly wheat and very little soybean, lending it a light appearance and sweet taste. It is more commonly used in the Kansai region to highlight the appearances of food, for example sashimi.
Indonesian
In Indonesia, soy sauce is known as kecap (also ketjap), which is a catch-all term for fermented sauces, and cognate to the English word “ketchup”. The term kecap is also used to describe other non-soy-based sauces, such as kecap ikan (fish sauce) and kecap inggris (worcestershire sauce). Three common varieties of Indonesian soy-based kecap exist:
Kecap asin is a salty soy sauce, very similar to Chinese light soy sauce, but usually somewhat thicker and has a stronger flavor; it can be replaced by light Chinese soy sauce in some recipes. Salty soy sauce was first introduced into Indonesia by Hokkien people so its taste resembles that of Chinese soy sauce. Hakka soy sauce made from black beans is very salty and large productions are mainly made in Bangka Belitung Islands.
Kecap manis is a sweet soy sauce, which has a thick, almost syrupy consistency and a unique, pronounced, sweet somewhat treacle-like flavor due to generous addition of palm sugar. In cooking, it could be replaced by molasses with a little vegetable stock stirred in. However this is different than the smooth and mild sweetness of palm sugar and the strong flavor of fermented soy, as molasses can tend to have bitter flavors.
Kecap manis sedang is a medium sweet soy sauce, which has a less thick consistency, is less sweet and has a saltier taste than kecap manis.
In Indonesian cuisine, kecap sauces are used either in cooking or as condiments. Kecap manis is an important sauce in Indonesian signature dishes, such as nasi goreng, mie goreng, satay, tongseng and semur. Sambal kecap, for example, is a type of dipping sauce of kecap manis with sliced chili, tomato and shallot, a popular dipping sauce for sate kambing (goat meat satay) and ikan bakar (grilled fish/seafood). Since soy sauce is of Chinese origin, kecap asin is also an important seasoning in Chinese Indonesian cuisine.