Developed in Japan over a millennium ago, MISO is a full-bodied savory or sweetly salty fermented food which adds deep flavor notes to both traditional Japanese and Western dishes, alike, yet also has health-promoting properties and essential antioxidants to maintain good health in our modern world.
Why Japanese Miso is so healthy
Due to the interaction between soybeans and koji-inoculated grains that, along with salt, are the basic ingredients used in the preparation of miso, miso has a number of essential health-giving components. Miso suppresses high blood pressure: By drinking miso soup regularly, one can reduce overall sodium intake by 30%. Furthermore, miso directly lowers blood pressure due to inherent components that make it easier to release salt from the kidneys. Ingestion of one bowl of miso soup a day also improves blood vessel age and has skin-beautifying and moisturizing effects because of the antioxidants contained in miso. There is also strong evidence which points to consuming miso in the daily diet as a way to ward the body against cancer. While all lofty claims, the overwhelming evidence does seem compelling, and the fact that the people of Japan live longer than in any country in the world is proof that Japan historically has had a healthy lifestyle and diet.
History of Miso
The earliest record of the use of miso in Japan appears in the Taiho code of 701. Scholars cannot
say with absolute certainty whether miso was first introduced to Japan from Korea or China or
whether it evolved organically from within Japan itself, or indeed all three. While various theories
exist, it is commonly held that the method of making miso from tama (fermented miso balls)
originated in Korea and is the progenitor to most Japanese farmhouse miso. Whereas the method
of fermenting miso from koji-inoculated grains was transmitted from China, most likely through
Buddhist channels, and was the method favored by the nobility and in monastaries. Furthermore,
there is speculation that the evidence of salt-making during the prehistoric Jomon period and the
fermented fish and meat concoctions of Yayoi (300 B.C.–300 A.D.) point to a native miso-making
culture, which naturally evolved in the northeastern region of Japan, known as the “miso heartland.”
In any case, the making of miso can be traced back undisputably to as early as 700 A.D. — well over
1000 years ago.
Miso was mentioned in the Engishiki (927 A.D.) as a soup ingredient for the wealthy in the 10th
century, but because of its expense, most people could only eat a small dab of miso on rice or
pickled vegetables. Also miso was an important seasoning added to simmered fish or vegetables,
and thinned with vinegar, became a sauce for a salad of raw fish (namasu). By the 18th century,
soy sauce had virtually replaced miso as the flavoring agent in urban areas, and by the year
2000, 90% of miso used in Japan was used for soup.
Miso soup, as we know it today, evolved in the Muromachi period (1336–1573) when miso
soup–making parties emerged as a popular past time. the host would prepare the basic soup (atsume
jiru) with seasonal ingredients and the guests would bring side dishes to enjoy with the communal
soup. A rudimentary version of instant miso soup developed in Muromachi by samurai going to
battle. Dried taro stems were simmered in miso then braided into long ropes (imogara nawa), which
the samurai wore around their waists. The samurai cut pieces of the miso-simmered rope off while on
the battlefield and poured boiling water over to create an instant life-sustaining ration.
The main flavoring of Japan shifted from miso to soy sauce in urban areas over a period of more
than two centuries. However, in rural areas, miso remained the seasoning of choice over soy
sauce well up to the end of the 20th century. And while many farm families continued making
their own miso up until the 1950s, it was rare to make soy sauce because of its difficulty.
Nonetheless, miso adds saltiness, flavor, and fragrance to food, so is experiencing a worldwide
increase in popularity and use. And with a high content of glutamate acid, miso contributes
both tart and sweet elements along with complex flavor structures. The paradox of Japanese
haute cuisine is the saying: “Not to cook is the ideal of cooking,” and miso is an exceptional
method to introduce complex, fermented salt notes to any cuisine.
While most miso is fermented to some degree, there is a wide range of differences between miso
in regards to ratio of koji to soybeans as well as fermentation period.
Koji (Aspergilus oryzae) is a spore that has been used for fermentation in Japan for thousands of
years. It is the mysterious, magical element that enables complex fermentation of Japanese
traditional foods such as miso, soy sauce, rice vinegar, and mirin. Miso with a high percentage
of koji tends to be barely fermented, or perhaps better put, matured rather than fermented, and
has a quite mild profile. Unfermented miso is more like a salty-sweet condiment—much loved
in the areas where it is made and often used for classical preparations in restaurants—this style
of miso could be added to cookie or cake batter to give a slight, yet essential boost of richness.
Local areas that make fermented miso crave the mellow and savory characteristics that develop
naturally over time. The complex fermentation notes and heady aromas of such miso are highly
valued, as well as virtually addicting. and this kind of miso should be considered almost like a
savory salt-plus condiment. Also, each miso maker prides itself on making its own proprietary
koji since koji is one of the key factors to determine taste in miso. It is said that you cannot
make the same miso even when using the same ingredients because koji always develops subtle
variations to its flavor profile each time.
Fermented foods introduce probiotics into our diet and are crucial elements to promote good
health through cooking. Full flavored and naturally sweet and well-balanced by acid, they add
powerful nuances to any dish. Fermenting provides the benefit of preservation while making
foods more digestible and more nourishing. Fermented foods are central to artisanal and
traditional foodways and defy globalization and industrialization of food in the modern world.
And Japan is the country of fermentation.
Worldwide, the fermentation boom has taken hold and miso is the poster child ingredient for
this movement: Intrepid chefs and fermentation aficionados are wildly experimenting with the
making of any number of unusual misos—some to better degrees of success than other.
Nonetheless, the Japanese method of making miso has stood the test of a time without variation
over a millennium so this beautifully simple method that follows the natural rhythm of the
seasons and the autumn harvest is deserving of the respect it commands. Miso is a homely yet
extraordinary condiment that can be the star of a dish or slipped into any preparation as a
hidden taste (kakushi aji) to add complexity and beneficial components.
Types of Miso
Miso types are determined by the koji-inoculated grain used to make each miso (i.e. rice, barley,
or soybean). The process to make miso, whether automated or artisanal, basically does not
differ, and involves a two-step fermentation process. The grain used for incubating koji is
soaked overnight, drained, steamed 80%, cooled to body temperature and then inoculated with
koji spores (Aspergillus oryzae) before being held in a humid anaerobic environment to
propogate for 2 days. The koji-inoculated rice, barley, or soybean is mixed with cooked
soybeans, which have been soaked over night before steaming and grinding, salt, and sometimes
a little “seed miso” (tane miso) from the previous year’s batch. The mash is packed in cedar
barrels, enamel tanks, or fiberglass vats, and left to ferment for weeks, months, or years,
depending on the type of miso. Good bacteria transforms simple sugars into various organic
acids which, in turn, impart distinctive proprietary flavor profiles to the miso while also
From quick-fermented shiro miso and Kaga miso to 6-months- or 1-year-fermented inaka miso,
kome miso represents a fairly wide range of flavors. Quick-fermented varieties are made with an
appreciably larger percentage of koji than other misos and have a sweet, only slightly salty
profile with little fermentation. These quick-fermented sweeter varieties are good for adding a
gentle miso flavoring to vegetable dishes or fish marinades. Inaka miso is an excellent choice as a
basic miso since it is mild, yet still has heady fermentation notes for savory dishes.
Soybeans, barley koji, and salt, which are traditionally fermented for 6 months to 1 year (one
summer). Soft, luscious, and fragrant from the barley, mugi miso is particularly good in
simmered dishes but absolutely delicious in just about anything. Highly favored in Western
Europe—perhaps because mugi miso goes well with olive oil.
Long-fermented for 2 to 3 years from soybeans, soybean koji, and salt. Dark and deeply
flavored with lovely beery notes, mame miso makes rich winter broths, and is a good candidate
for mixing with lighter miso varieties (awase miso) to add overall complexity. Hatcho miso is a
type of mame miso produced in Aichi prefecture in central-eastern Japan and is weighted with
massive rocks for 2½ years, to promote fermentation and intensity of flavor.