
Soy sauce

Soy sauce (also called simply soy in American English and soya sauce less frequently in British English) is a liquid condiment of Chinese origin, traditionally made from a fermented paste of soybeans, roasted grain, brine, and "Aspergillus oryzae" or "Aspergillus sojae" molds. It is considered to contain a strong umami flavor. 
Soy sauce in its current form was created about 2,200 years ago during the Western Han dynasty of ancient China, and spread throughout East and Southeast Asia where it is used in cooking and as a condiment.
Use and storage.
Soy sauce can be added directly to food, and is used as a dip or salt flavor in cooking. It is often eaten with rice, noodles, and sushi or sashimi, or can also be mixed with ground wasabi for dipping. Bottles of soy sauce for salty seasoning of various foods are common on restaurant tables in many countries. Soy sauce can be stored at room temperature.
History.
East Asia.
China.
Soy sauce (醬油, "jiàngyóu") is considered almost as old as soy paste—a type of fermented paste (Jiang, ) obtained from soybeans—which had appeared during the Western Han dynasty (206 BC – 220 AD) and was listed in the bamboo slips found in the archaeological site Mawangdui (馬王堆). There are several precursors of soy sauce that are associated products with soy paste. Among them the earliest one is "Qingjiang" (清醬) that had appeared in AD 40 and was listed in "Simin Yueling" (). Others are "Jiangqing" (醬清), "Chizhi" (豉汁) and "Chiqing" (豉清) which are recorded in "Qimin Yaoshu" () in AD 540. By the time of the Song dynasty (960–1279 AD), the term "soy sauce" (醬油) had become the accepted name for the liquid condiment, which are documented in two books: "Shanjia Qinggong" (山家清供) and "Pujiang Wushi Zhongkuilu" (浦江吳氏中饋錄) during the Song dynasty (960–1279 AD).
Like many salty condiments, soy sauce was originally a way to stretch salt, historically an expensive commodity. During the Zhou dynasty of ancient China, fermented fish with salt was used as a condiment in which soybeans were included during the fermentation process. By the time of the Han dynasty, this had been replaced with the recipe for soy paste and its by-product soy sauce, by using soybeans as the principal ingredient, with fermented fish-based sauces developing separately into fish sauce.
The 19th century Sinologist Samuel Wells Williams wrote that in China, the best soy sauce is "made by boiling beans soft, adding an equal quantity of wheat or barley, and leaving the mass to ferment; a portion of salt and three times as much water are afterwards put in, and the whole compound left for two or three months when the liquid is pressed and strained".
Japan.
Originally, a common Japanese condiment was uoshōyu, which was fish based. When Buddhism came to Japan from China in the 7th century, they introduced vegetarianism and brought many soy-based products with them, such as soy sauce, which is known as "shōyu" (醤油 "shōyu") in Japan. Shoyu exportation began in 1647 by the Dutch East India Company.
Korea.
The earliest soy sauce brewing in Korea seems to have begun prior to the era of the Three Kingdoms c. 57 BCE. The "Records of the Three Kingdoms", a Chinese historical text written and published in the 3rd century, mentions that "Goguryeo people are good at brewing fermented soy beans." in the section named "Dongyi" (Eastern foreigners), in the "Book of Wei". Jangdoks used for soy sauce brewing are found in the mural paintings of Anak Tomb No.3 from the 4th century Goguryeo.
In "Samguk Sagi", a historical record of the Three Kingdoms era, it is written that "ganjang" (soy sauce) and "doenjang" (soybean paste) along with "meju" (soybean block) and "jeotgal" (salted seafood) were prepared for the wedding ceremony of the King Sinmun in February 683. "Sikhwaji", a section from "Goryeosa" (History of Goryeo), recorded that "ganjang" and "doenjang" were included in the relief supplies in 1018, after a Khitan invasion, and in 1052, when a famine occurred. Joseon texts such as "Guhwangchwaryo" and "Jeungbo sallim gyeongje" contain the detailed procedures on how to brew good quality "ganjang" and "doenjang." "Gyuhap chongseo" explains how to pick a date for brewing, what to forbear, and how to keep and preserve "ganjang" and "doenjang".
Europe.
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, diplomat and scholar Isaac Titsingh published accounts of brewing soy sauce. Although earlier descriptions of soy sauce had been disseminated in the West, his was among the earliest to focus specifically on the brewing of the Japanese version. By the mid-19th century, Japanese soy sauce gradually disappeared from the European market, and the condiment 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. Soy sauce made from ingredients such as Portobello mushrooms were disseminated in European cookbooks during the late 18th century. A Swedish recipe for "Soija" was published in the 1770 edition of Cajsa Warg's "Hjelpreda i Hushållningen för Unga Fruentimber" and was flavored with allspice and mace.
United States.
The first soy sauce production in the United States began in the Territory of Hawaii in 1908 by the Hawaiian Yamajo Soy Company. La Choy started selling hydrolyzed vegetable protein based soy sauce in 1933.
Production.
Soy sauce is made either by fermentation or by hydrolysis. Some commercial sauces have both fermented and chemical sauces.
Flavor, color, and aroma developments during production are attributed to non-enzymatic Maillard browning.
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.
Traditional.
Traditional soy sauces are made by mixing soybeans and grain with mold cultures such as "Aspergillus oryzae" and other related microorganisms and yeasts (the resulting mixture is called "koji" in Japan; the term "koji" is used both for the mixture of soybeans, wheat, and mold as well as for the mold itself). Historically, the mixture was fermented naturally in large urns and under the sun, which was believed to contribute extra flavors. Today, the mixture is placed in a temperature and humidity controlled incubation chamber.
Traditional soy sauces take months to make:
Acid-hydrolyzed vegetable protein.
Some brands of soy sauce are made from acid-hydrolyzed soy protein instead of brewed with a traditional culture. This takes about three days. Although they have a different flavor, aroma, and texture when compared to brewed soy sauces, they can be produced more quickly and cheaply, and also have a longer shelf life and are usually made for these reasons. The clear plastic packets of dark sauce common with Chinese-style take-out food typically use a hydrolyzed vegetable protein formula. Some higher-priced hydrolyzed vegetable protein products with no added sugar or colorings are sold as low-sodium soy sauce alternatives called "liquid aminos" in health food stores, similar to the way salt substitutes are used. These products are, however, not necessarily low in sodium.
High-salt liquid-state fermented soy sauce.
High-salt liquid-state fermentation (HLF) of soybeans depends heavily on microbial activity, metabolism and enzymatic hydrolysis of macro-nutrients. 
Low-salt solid-state fermented soy sauce.
LSF, also referred as rapid fermenting, is a modern fermentation method invented in response to high market demand. 
Chemical composition.
The chemical composition of soy sauce can be affected easily by raw materials, fermentation methodologies, fermenting molds and strains, and post-fermentation treatments. Although the formation mechanism of chemical composition in soy sauce is complex, it has been widely accepted that free amino acids, water-soluble peptides and Maillard reaction products in soy sauce are considered as essential chemical composition and to provide core sensory effects. 
The primary fermentation of lactic-acid-fermenting halophiles lowers the pH of the moromi, and this directly results in the acidic pH range (4.4–5.4) of soy sauce products. The secondary fermentation conducted by heterofermentative microbes provides soy sauce with a wide range of flavor and odorant compounds by breaking down macro-nutrients. Soy proteins and grain proteins are hydrolyzed into short peptide chains and free amino acids, which adds umami to the product. Based on the result of free amino acid analysis, the most abundant amino acids in Chinese soy sauce product are glutamic acid, aspartic acid, alanine and leucine.
Starch is hydrolyzed into simple sugars which contribute to the sweet flavor in soy sauce. Legume fats may also be decomposed into short chain fatty acids, and the interactions among lipids and other macronutrients also result in a richer flavor in the final product. Non-enzymatic browning also contributes significantly to the development of the properties of soy sauce. The hydrolysis of proteins and large carbohydrates also provides free amino acids and simple sugars as reagents for the Maillard reaction.
Soy sauce may contain more than 1% alcohol and may run afoul of liquor control legislation.
Sensory profile.
The taste of soy sauce is predominated by saltiness, followed by moderate umami, sweet taste, and finally slight bitterness, which is hard to perceive due to the masking effect of other tastes. The overall flavor of soy sauce is a result of the balance and interaction among different taste components. The saltiness is largely attributed to the presence of NaCl (common salt) in brine. The sugars hydrolyzed from starch add sweetness into soy sauce. Umami is largely caused by the presence of free amino acids. Additionally, the interaction between glutamine and sodium cation may have given rise to sodium glutamate (MSG), which can further contribute to the umami flavor. Basic tastes can also be attributed to amino acid groups arranged in specific sequence. In soy sauce, it was found that "amino acids were grouped as MSG-like (monosodium glutamate-like) (Asp+Glu), sweet (Ala+Gly+Ser+Thr), bitter (Arg+His+Ile+Leu+Met+Phe+Trp+Try+Val), and tasteless (Cys+Lys+Pro)".
Despite a large variety of volatile and odorant compounds that have been identified in soy sauce, the food product "per se" does not present a strong aroma. Alcohols, acids, esters, aldehydes, ketones, phenols, heterocyclic compounds, alkynes and benzenes have been identified in Chinese soy sauces. An explanation for this observation is that the aroma of soy sauce does not depend largely on the aroma-active compounds. The subtle aroma is a result of a "critical balance" achieved among all volatile and odorant compounds, whose respective concentrations are relatively low.
Variations by country.
Soy sauce is widely used as an important flavoring and has been integrated into the traditional cuisines of many East Asian and Southeast Asian cultures. Despite their rather similar appearance, soy sauces made in different cultures and regions are different in taste, consistency, fragrance and saltiness. Soy sauce retains its quality longer when kept away from direct sunlight.
Burmese.
Burmese soy sauce production is dated back to the Bagan era in the 9th and 10th century. Scripts written in praise of "pe ngan byar yay" (, literally "bean fish sauce") were found. Thick soy sauce is called "kya nyo" (, from Chinese "jiàngyóu").
Chinese.
Chinese soy sauces (; or alternatively, ; ) are primarily made from soybeans, with relatively low amounts of other grains. Chinese soy sauce can be roughly split into two classes: brewed or blended. Chinese soy sauces can also be classified into Low-Salt Solid-State fermented soy sauce (LSF), and High-Salt Liquid-State fermented soy sauce (HLF).
Brewed.
Soy sauce that has been brewed directly from a fermentation process using wheat, soybeans, salt, and water without additional additives.
Blended.
Additives with sweet or umami tastes are sometimes added to a finished brewed soy sauce to modify its taste and texture.
Filipino.
In the Philippines, soy sauce is called "toyo" in the native languages, derived from "tau-yu" in Philippine Hokkien. Philippine soy sauce is usually a combination of soybeans, wheat, salt, and caramel color. It is thinner in texture and has a saltier taste than its Southeast Asian counterparts. It is most similar to the Japanese "koikuchi shōyu" in terms of consistency and the use of wheat, though "toyo" is a bit saltier and darker in color.
"Toyo" is used as a marinade, an ingredient in cooked dishes, and most often as a table condiment, usually alongside other sauces such as fish sauce ("patís") and sugar cane vinegar ("sukà"). It is often mixed and served with the juice of the calamansi (× "Citrofortunella microcarpa"; also called calamondin, "limonsito"). The combination is known as "toyomansî", which can be comparable to the Japanese "ponzu" sauce (soy sauce with yuzu). "Toyo" is also a main ingredient in Philippine adobo, one of the more famous dishes of Filipino cuisine.
Hawaiian.
Soy sauce is a very popular condiment and marinade for many dishes in the Hawaiian cuisine. "Aloha shoyu" is soy sauce made in the Islands. Soy sauce is sometimes known by it's Japanese name (less commonly ), in Hawaii.
Indonesian.
In Indonesia, soy sauce is known as "kecap" (old spelling: "ketjap"), which is a catch-all term for fermented sauces, and cognate to the English word "ketchup". The most popular type of soy sauce in Indonesian cuisine is "kecap manis" or sweet soy sauce. The term "kecap" is also used to describe other non-soy-based sauces, such as "kecap ikan" (fish sauce) and "kecap Inggris" (worcestershire sauce; lit. "English sauce", due to Worcestershire sauce originating in England). Three common varieties of soy-based "kecap" exist in Indonesian cuisine, used either as ingredients or condiments:
Japanese.
 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 as 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 50% wheat.
Varieties.
Newer varieties of Japanese soy sauce include:
All of these varieties are sold in three different grades according to how they were made:
All the varieties and grades may be sold according to three official levels of quality:
Korean.
In South Korea, soy sauces or "ganjang" (, "seasoning sauce") can be roughly split into two categories: "hansik ganjang" ('Korean-style soy sauce') and ('modernized soy sauce'). The term can also refer to non-soy-based salty condiments, such as fish sauce".
"Hansik ganjang".
 (, 'Korean-style soy sauce') is made entirely of fermented soybean (meju) and brine. It is a byproduct of "doenjang" (fermented soybean paste) production, and has a unique fermented soybean flavour. Both lighter in colour and saltier than other Korean ganjang varieties, "hansik ganjang" is used mainly in guk (soup) and namul (seasoned vegetable dish) in modern Korean cuisine. Common names for "hansik ganjang" include "jaeraesik ganjang" (, "traditional soy sauce"), "Joseon-ganjang" (, "Joseon soy sauce"), and "guk-ganjang" (, "soup soy sauce"). The homebrewed variety is also called "jip-ganjang" (, "home soy sauce").
Depending on the length of aging, "hansik ganjang" can be divided into three main varieties: clear, middle, and dark.
Korean Ministry of Food and Drug Safety's Food Code classifies "hansik-ganjang" into two categories by their ingredients.
"Gaeryang ganjang".
"Gaeryang-ganjang" (, "modernized soy sauce"), referring to varieties of soy sauces not made of meju, is now the most widely used type of soy sauce in modern Korean cuisine. The word "ganjang" without modifiers in bokkeum (stir-fry), jorim (braised or simmered dishes), and jjim (steamed dishes) recipes usually mean "gaeryang-ganjang". Another common name of "gaeryang-ganjang" is "jin-ganjang" (, "dark soy sauce"), because "gaeryang-ganjang" varieties are usually darker in appearance compared to traditional "hansik ganjang". Having been introduced to Korea during the era of Japanese forced occupation, "garyang ganjang" is also called "Wae-ganjang" (, "Wae soy sauce").
Korean Ministry of Food and Drug Safety's Food Code classifies "gaeryang-ganjang" into four categories by their method of production.
Malaysian and Singaporean.
Malays from Malaysia, using the Malay dialect similar to Indonesian, use the word "kicap" for soy sauce. "Kicap" is traditionally of two types: "kicap lemak" (lit "fat/rich soy sauce") and "kicap cair". "Kicap lemak" is similar to Indonesian "kecap manis" but with very much less sugar while "kicap cair" is the Malaysian equivalent of "kecap asin".
Sri Lankan.
Soy sauce () is a popular food product used in Sri Lanka and is a major ingredient used in the nationally popular street food dish, Kottu. Soy sauce has largely been produced by the Sri Lankan Chinese community but its production has also spread to other communities in Sri Lanka. Soy sauce production in Sri Lanka is the same as the production of soy sauce in Indonesia. Fermentation occurs over a period of three months. The soy beans which are steeped in brine are then pressed to obtain a liquid sauce.
Taiwanese.
The history of soy sauce making in Taiwan can be traced back to southeastern China, in the provinces of Fujian and Guangdong. Taiwanese soy sauce is known for its black bean variant, known as black bean soy sauce (黑豆蔭油), which takes longer to make (about 6 months). Most major soy sauce makers in Taiwan make soy sauce from soybeans and wheat, and are widely popular, and are available in many Oriental Foods and Grocery Stores. Some make black bean soy sauce, which is very widely used in Chinese and Oriental cooking as an excellent flavor enhancer.
Thai.
In Thailand, soy sauce is called "sii-íu" (). "Sii-íu kǎao" (, 'white soy sauce') is used as regular soy sauce in Thai cuisine, while "sii-íu dam" (, 'black soy sauce') is used primarily for colour. Another darker-coloured variety, "sii-íu wǎan" (, 'sweet soy sauce') is used for dipping sauces. "Sɔ́ɔt prung rót" (, 'seasoning sauce') is also commonly used in modern Thai cuisine.
Vietnamese.
In Vietnam, Chinese-style soy sauce is called "xì dầu" (derived from the Cantonese name 豉油) or "nước tương". The term "soy sauce" could also imply other condiments and soy bean paste with thick consistency known as "tương". Both are used mostly as a seasoning or dipping sauce for a number of dishes. Vietnamese cuisine itself favors fish sauce in cooking but "nước tương" has a clear presence in vegetarian cuisine.
Nutrition.
A study by the National University of Singapore showed that Chinese dark soy sauce contains 10 times the antioxidants of red wine, and can help prevent cardiovascular diseases. Unpasteurized soy sauce is rich in lactic acid bacteria and of excellent anti-allergic potential.
Soy sauce does not contain the level of isoflavones associated with other soy products such as tofu or edamame. It can also be very salty, having a salt content between 14–18%. Low-sodium soy sauces are made, but it is difficult to make soy sauce without using some quantity of salt as an antimicrobial agent.
A serving of of soy sauce contains, according to the USDA:
Carcinogens.
Soy sauce may contain ethyl carbamate, a Group 2A carcinogen.
In 2001, the United Kingdom Food Standards Agency found in testing various soy sauces manufactured in mainland China, Taiwan, Hong Kong, and Thailand (made from hydrolyzed soy protein, rather than being naturally fermented) that 22% of tested samples contained a chemical carcinogen named 3-MCPD (3-monochloropropane-1,2-diol) at levels considerably higher than those deemed safe by the EU. About two-thirds of these samples also contained a second carcinogenic chemical named 1,3-DCP (1,3-dichloropropane-2-ol) which experts advise should not be present at any levels in food. Both chemicals have the potential to cause cancer, and the Agency recommended that the affected products be withdrawn from shelves and avoided. The same carcinogens were found in soy sauces manufactured in Vietnam, causing a food scare in 2007.
In Canada, the Canadian Cancer Society writes,
Allergies.
Soy sauce allergy not caused by soy or wheat allergy is rare. Most varieties of soy sauce contain wheat, to which some people have a medical intolerance. However, some naturally brewed soy sauces made with wheat may be tolerated by people with a specific intolerance to gluten because gluten is not detectable in the finished product. Japanese tamari soy sauce is traditionally wheat-free, and some tamari available commercially today is wheat- and gluten-free.