[12] The 19th century Sinologist Samuel Wells Williams wrote that in China, the best soy sauce was "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".

[21] 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.

[22] Joseon texts such as Guhwangchwaryo and Jeungbo sallim gyeongje contain the detailed procedures on how to brew good quality ganjang and doenjang.

Food historian Raymond Sokolov noted that the ingredients used in the dish, including soy sauce, likely were present in the native cuisine even before the colonial-era record.

[23] 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.

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.

[25] By the mid-19th century, Japanese soy sauce gradually disappeared from the European market, and the condiment became synonymous with the Chinese product.

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.

[31] Traditional soy sauces take months to make: High-salt liquid-state fermentation (HLF) of soybeans depends heavily on microbial activity, metabolism and enzymatic hydrolysis of macronutrients.

LSF evolved from salt-free solid-state fermentation, an even faster method working at even higher temperatures (50–65 °C (122–149 °F)) and taking 72 hours to complete,[37] introduced to China from the Soviet Union in 1958.

The aging time turned out to be too short develop a proper flavor profile, with burnt acidic notes left in the sauce.

LSF is a compromise between this method and the more traditional HLF: the product tastes passable with more microbes allowed to survive, but still lacks depth.

[38] 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.

The secondary fermentation conducted by heterofermentative microbes provides soy sauce with a wide range of flavor and odorant compounds by breaking down macronutrients.

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.

The hydrolysis of proteins and large carbohydrates also provides free amino acids and simple sugars as reagents for the Maillard reaction.

[43] 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.

The subtle aroma is a result of a "critical balance" achieved among all volatile and odorant compounds, whose respective concentrations are relatively low.

[citation needed] Chinese soy sauces (Chinese: 酱油; pinyin: jiàng yóu; Jyutping: zoeng3 jau4; Cantonese Yale: jeungyàuh; or alternatively, 豉油; pinyin: chǐyóu; Jyutping: si6jau4; Cantonese Yale: sihyàuh) are primarily made from soybeans, with relatively low amounts of other grains.

Besides the above traditional types, hydrolyzed vegetable protein and other flavor enhancers may be mixed with brewed soy sauce to produce cheaper substitutes.

(Hydrolyzed vegetable protein is not listed as a food additive in GB 2760 and is therefore unacceptable in products labelled as "soy sauce".

Soy sauce is a ubiquitous condiment and ingredient in many dishes in Hawaiian cuisine, where it is commonly known by its Japanese name shōyu by locals.

[56] 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.

Having been introduced to Korea during the era of Japanese forced occupation, garyang ganjang is also called Wae-ganjang (왜간장, "Wae soy sauce").

In Vietnam, Chinese-style soy sauce is called xì dầu (derived from the Cantonese name 豉油) or nước tương.

A study by the National University of Singapore showed that Chinese dark soy sauce contains 10 times the antioxidants of red wine.

[74] 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.