Umami, sweet and aromatic substances are produced during the fermentation process.ĭuring the Muromachi period about 600 years ago, a technique was created in Japan to grow different types of koji-mold separately by mixing koji-mold with charcoal. The koji-mold’s enzymes include protease, which breaks down proteins into amino acids, amylase, which breaks down starches into sugars, and lipase, which breaks down lipids. Various types of koji-mold are used to make miso, soy sauce, sake, and shochu ― Japanese distilled spirit. Koji-mold is the general term for filamentous fungi, which are used to make rice koji, barley koji and soybean koji, and is a type of mold. In October 2006, Aspergillus oryzae was designated as a 'national fungus' by the Nippon Jozo Gakkai (Brewing Society of Japan) due to its longstanding contributions to Japanese food culture and expectations that it will be used in an even wider range of fields in the future. Japan's very humid climate is said to be suited for the growth of koji-mold, and traditional fermented foods such as miso, soy sauce, sake, amazake, mirin, and vinegar are all made using koji-mold. Because food is closely related to health, it is no exaggeration to say that koji-mold has had an important presence in supporting Japan, a country where people live long lives.

It is an indispensable component when speaking about Japanese food culture. Koji-mold ( Aspergillus oryzae ) is one of the main ingredients of miso. In this way, miso that contains various amino acids, centered on glutamate that is an umami component, is made. In the soybean fermentation process, about 30% of the protein contained in soybeans is broken down into amino acids. However, it is reported that the ratio of glutamate to aspartate plays a part in creating the deliciousness of food. Umami taste intensity of aspartate has about one-tenth the umami of glutamate, so is thus quite weak. It is followed by aspartate, which is another amino acid with umami. As you can see in the figure below, glutamate is the most prevalent of the amino acids in soybean protein. Although the protein does not have a taste, it is broken down into its amino acids through the fermentation process in which it is made into miso. The amino acid varieties and their quantities present in soybeans are shown in the figure below. Proteins are made up of 20 kinds of amino acids. Soybeans, an ingredient of miso, contain abundant protein. This is due to miso’s high nutritional value, including its abundance of essential amino acids, and its effects for preserving food and making meat and fish tender. In this way, miso took root deeply among Japanese people, and is still an indispensable seasoning in Japanese cuisine today.Īlthough it is common to use miso and dashi together, various new ways of using miso are being created in modern times, including using it for foods other than Japanese cuisine as an all-purpose seasoning. Commoners began brewing their own miso during the Muromachi period (1333-1573), and it began to be industrially produced entering the Edo period (1603-1868). Consuming miso in the form of soup was popularized, and miso became an essential part of the Japanese diet. Around the Kamakura period (1185-1333), the samurai meal custom known as “Ichiju Issai” (literally meaning one soup, one dish) became established.

It was rarely consumed in the form of miso soup then, and was instead eaten as a side dish or as medicine. It was originally a luxurious, prized food that could only be eaten by small, privileged groups of people. Miso is believed to have been brought into Japan from China.

Types of miso paste