The raw materials for soy sauce are protein and starch.

Plant protein is taken from bean cake after soybean oil extraction or soybean meal after oil extraction by solvent, and it is also replaced by peanut cake and broad bean. In traditional production, soybean is the main one. Wheat and bran are widely used as starchy raw materials, and some are replaced by broken rice and corn. In traditional production, flour is the main material.

The raw materials are steamed and cooled, inoculated with pure cultured Aspergillus oryzae seeds to make sauce koji, which is moved into a fermentation tank, fermented with salt water, and then the soy sauce is extracted by leaching when the fermented grains are mature.

The purpose of koji-making is to make Aspergillus oryzae fully grow and develop on koji, and to produce and accumulate a large number of needed enzymes, such as protease, peptidase, amylase, glutaminase, pectinase, cellulase and hemicellulase.

In the process of fermentation, the formation of taste is through the action of these enzymes.

For example, protease and peptidase hydrolyze protein into amino acids, resulting in umami flavor; Glutaminase turns tasteless glutamine into vulgar glutamic acid with delicious taste; Amylase hydrolyzes the sediment into sugar to produce sweetness; Pectinase, cellulase and hemicellulase can completely rupture the cell wall and make protease and amylase hydrolyze more thoroughly.

At the same time, in the process of koji-making and fermentation, yeast and bacteria falling from the air also proliferate and secrete a variety of enzymes. Pure cultured lactic acid bacteria and yeast can also be added.

lactic acid is produced by lactic acid bacteria, ethanol is produced by yeast fermentation, and many components such as alcohol, acid, aldehyde, ester, phenol, acetal and furanone produced by raw materials and metabolites of Aspergillus are mostly trace, but they can constitute the complex aroma of soy sauce.

In addition, tyrosine in protein is oxidized to produce melanin, and classical mildew amylase in the sediment is hydrolyzed to glucose, which reacts with amino acids to produce melanoid, which makes soy sauce produce bright and shiny reddish brown.

umami flavor, sweet taste, sour taste, wine flavor and ester flavor produced by a series of extremely complicated biochemical changes during fermentation are mixed with the salty taste of salt water, and finally soy sauce with unique color, flavor and flavor is formed.

Extended information:

Soy sauce evolved from' sauce'. As early as 3, years ago, it was recorded in the Zhou Dynasty to make soy sauce. The brewing of soy sauce was discovered purely by accident. Soy sauce originated from the condiment used by the ancient emperor of China.

The earliest soy sauce was marinated with fresh meat, which was similar to the manufacturing process of fish sauce today. Because of its excellent flavor, it gradually spread to the people. Later, it was found that soybean was made with similar flavor and cheap, so it was widely spread to eat.

In the early days, with the spread of Buddhist monks, it spread all over the world, such as Japan, South Korea and Southeast Asia. The manufacture of soy sauce was a family art and secret in the early days. Its brewing was mostly controlled by a master, and its technology was often passed down from generation to generation or passed down by a group of masters, forming a certain way of brewing.

The oil produced by chopping meat into paste and fermenting it is called "sugar" (meaning meat soy sauce); Another version of the sauce in which animal blood is added is called fermented grains. It can be seen from the sentence of "The Book of Songs, Daya, Hangqi": "I recommend it".

Huang Xingzong thinks that "bean paste clear" referred to in Qi Min Yao Shu may be the predecessor of plant soy sauce.

Soy sauce has been accepted by people in the Song Dynasty: the word soy sauce first appeared in two works in the Southern Song Dynasty: Shan Jia Qing Gong recorded that spring Xun, fish and shrimp were fried with soy sauce and sesame oil; "Wu's Feed Record" records that crabs are steamed with wine, soy sauce and sesame oil.

Since then, the word soy sauce has appeared in Yunlintang Dietary System Collection in 136, Yi Ya's Legacy in Yuan Dynasty, Notes on Drinking and Taking Food in 1591, Secrets of Food Constitution in 168, Records of Raising Children in 1698, Records of Awakening Garden in 175 and 179.

In Song Dynasty, all kinds of sauces obtained by processing soy sauce and fermented soybean, called soy sauce, became popular in China's diet as a condiment. By the Qing dynasty, the use of soy sauce far exceeded that of soy sauce. In 179, soy sauce has achieved an important position in the menu with the garden.

The word "soy sauce" was first used in Japanese literature in 1597, but the production method of soy sauce may have been introduced to Japan from China before that.

Soy sauce evolved and developed from soybean paste. The earliest use of the name "soy sauce" in the history of China was in the Song Dynasty. In Lin Hong's book "Shan Jia Qing Gong", there is a description that "the leek leaves are tender and mixed with shredded ginger, soy sauce and vinegar".

In addition, there are other names of ancient soy sauce, such as clear sauce, clear bean sauce, sauce, sauce, soy sauce, soy sauce, drenched oil, grapefruit oil, sun-dried oil, seat oil, hidden oil, autumn oil, mother oil, set oil and double set oil.

After 755 AD, soy sauce production technology was introduced to Japan with Jian Zhen. Later, it was introduced to Korea, Vietnam, Thailand, Malaysia, the Philippines and other countries.