The Soy Sauce Professor's Column

Where did soy sauce come from?

It is said that the soy sauce's roots are in "jiàng miso" which was introduced by ancient China as its name suggests. It is not clear when this was circulated in Japan as "hishio miso", but according to the Taiho Code, it is said that a "hishio miso" similar to soy sauce that was made in an office in the Imperial household.

Entering the Kamakura period, it is said that a Shinshu Zen Buddhist priest called Kakushin, brought back miso's production process from China, and that the liquid that had collected in the bucket was close to the current tamari soy sauce.

In the Muromachi era, something close to the current soy sauce was produced. It was also around this time that the word "soy sauce" was created, and it is said that the first time it appeared in literature was in the the Azuchi-Momoyama era's Everyday Language Dictionary the "Ekirinbon Setsuyoshu".
The brewing of soy sauce became popular from around the end of the Muromachi era, and catered to the taste of the people, "koikuchi soy sauce" spread through the Edo era.

During the Meiji era, when exchange with overseas began, Western condiments such as sauce and ketchup were introduced, and resulted in their production even in Japan. However, the status of soy sauce was not shaken, with the economic boom that visited after the First World War, the production output expanded rapidly, and the spread to the general household progressed all at once.

When entering the Showa era, when it became difficult to obtain raw materials due to the outbreak of the Second Sino-Japanese War, soy sauce became regulated goods and began incurring distribution restrictions. The era of free competition came when World War II ended, the rationing corporation was abolished, price control was also abolished, and soy sauce manufacturers aimed at quality improvement again. Half a century passed since then, a lot of homogeneous and superior soy sauces have been produced and exported to dozens of countries as well as in Japan.
Soy sauce nurtured by the climate and culture of Japan continues to expand its range as a flavoring for the world.

(Soy sauce so far and hereafter P15 / Excerpt from Japan Soy Sauce Technology Center)

Food tastes are divided into 5: sweet, sour, spicy, bitter, and salty.
Soy sauce has these five flavors and with the addition of the delicate component that is "umami", the taste composition is complete.

Soy sauce contains plenty of natural umami flavor. That is due to the brewing producing many amino acids working together, dissolving with other ingredients then being drawn out.

Salt water only contains 3% salt, but soy sauce contains 16 -18% salt. But even if it is held in your mouth, it is not as salty as salt water. This is because the umami of the soy sauce is mellow. A good "aroma" that looks delicious is necessary for cooking. This "aroma" is called a cooking flavor (heated aroma), and is when the alcohol content produced by fermentation in soy sauce is in effect.

In soy sauce, there is a sterilizing power to kill E. coli. and the like in a short period of time. This is because lactic acid and other organic acids in the ingredients, with some high concentration of salts coexist and work together. It also contains many useful amino acids indispensable to the human body. Especially lysine and threotin are valuable because they are not included in such staple foods as rice and bread.

Essential amino acids cannot be assembled if they lack even one protein, and so the remaining are broken down. Because of this, the body weakens, a feeling of exhaustion occurs, and it becomes oversensitive.

Nowadays, salt included in soy sauce is a problem. To prevent high blood pressure and heart disease, it is necessary to refrain from excessive salt consumption. The target value of salt intake per day by the Ministry of Health, Labor and Welfare is set to 7 g for male 8 g female. However, it is necessary to ingest an appropriate amount of salt suitable for the body, as we cannot do without it for maintaining healthy blood.

The unique characteristics of soy sauce are varied due to preferences in various parts of Japan and the history of brewing.
These different varieties are classified into five types according to Japan Agricultural Standards (JAS).

	Main Producing Area	Soy Sauce Characteristics	Main Usage Rules
	Nationwide Production Volume Ratio
	Ingredient Characteristics		Suggested Dishes
Koikuchi Soy Sauce	Nationwide	Soy sauce that is used throughout Japan. In addition to saltiness, it combines and possesses a deep umami flavor, mild sweetness, fresh sourness, and stern bitter taste. An all-purpose flavoring that you can broadly use.	The typical soy sauce.
	Nationwide Production Volume Approx. 83.8%
	Uses approx. the same amount of soybeans and wheat.		Yellowtail and daikon radish/Ginger-fried pork
Usukuchi Soy Sauce	Most of Western Japan, roughly Nationwide	A light type of soy sauce. The salt content is about 10% higher than koikuchi soy sauce. Add sweet half sake to mellow the taste. It is ideal for cooking and simmering that make use of the ingredient's flavor.	Use with boiled vegetables and clear soups that make the best use of the type of the ingredients.
	Nationwide Production Volume Approx. 12.8%
	Uses approx. the same amount of soybeans and wheat; a small amount of rice.		Takikomi Rice/Clear soup
Tamari Soy Sauce	Aichi/Mie/Gifu	A distinctive soy sauce that has a thickness and strong umami flavor, with a unique aroma. In addition to being used for table use, as it is called "sashimi tamari", it is also used for processed food that you want to finish nicely with color and lustre.	Take advantage of the beautiful redness after heating, and use it for Teriyaki, Tsukudani, rice crackers and so on. It is also popular as a fish sauce for something like sashimi.
	Nationwide Production Volume Approx. 1.5%
	Uses only soybeans. There are times when a small amount of wheat can be added.		Pork kakuni/Fried rice balls
Saishikomi Soy Sauce	Chugoku/Kyushu	In order to prepare this, koji mold is once again added to completed raw soy sauce, and it is called "saishikomi soy sauce". It is rich in color, taste and aroma, it has a sweetness and it is also called "sweet soy sauce".	Due to its thickness and having a deep taste, this soy sauce's umami flavor can be drawn out in a small amounts. It is also used as a fish sauce for something like sashimi, as a subtle seasoning to bring out the flavor.
	Nationwide Production Volume Approx. 1.0%
	Prepared in the same way as koikuchi soy sauce, raw soy sauce is put into the koji mold.		Rice with raw egg/ Topping for vanilla ice cream
Shiro Soy Sauce	Aichi	Produced in the Hekinan area of Aichi prefecture, it is a more lightly amber-colored soy sauce than usukuchi soy sauce. The fermenting time is short, the taste is light while having a strong sweetness, and it has a unique aroma.	Used for such things as clear soups, steamed egg hotchpotch, as well as stews, hot pots, and tamagoyaki that make the best use of the variety's lightness and aroma.
	Nationwide Production Volume Approx. 0.9%
	Uses quite a small amount of soybeans and wheat.		Steamed egg hotchpotch/lightly pickled vegetables

(Soy sauce so far and hereafter P15 / Excerpt from Japan Soy Sauce Technology Center)

The recipe depends on three types of manufacturing methods.

Honjozo Fermentation Method	In a recipe from olden times, with soybeans and wheat as ingredients, it is a soy sauce brewed from squeezing moromi made by fermenting by yeast cells, adding brine and letting it mature.
Mixed Fermented Method	Soy sauce made by squeezing what was fermented/aged for about one month or more by adding amino acid liquids and so on to the moromi made by the honjozo brewing system.
Mixing Method	Soy sauce made by adding amino acid liquids and so on to deep-fried bean curds made by the honjozo brewing method.