Introduction
Washoku or Japanese traditional food culture was registered as a UNESCO Intangible Heritage in December
2013, and will mark the 10th anniversary of its registration in 2023.
The Ministry of Agriculture, Forestry and Fisheries of Japan set the export targets of 2 trillion yen by 2025 and 5
trillion yen by 2030 for agricultural, forestry, fishery and food products in the Basic Plan for Food, Agriculture
and Rural Areas (approved by the Cabinet on March 31,2020) and the Basic Policy on Economic and Fiscal
Management and Reform 2020 and the Follow-up on the Growth Strategy (approved by the Cabinet on July 17,2020), and compiled measures to achieve these targets in the form of the Strategy to Realize Export Expansionof Agricultural, Forestry, Fishery and Food Products in December 2020.
Looking at overseas trends, the number of overseas Japanese food restaurants increased from approx. 55,000
restaurants in 2013 to approx. 159,000 restaurants in 2021, which shows that Japanese foods are remarkably high indemand and popularity. It is considered that the reason for this is that Japanese foods have diverse dimensions
such as their tastiness, history, and healthiness, and Japanese agricultural, forestry, and fishery products can bedifferentiated from those made in other countries. As awareness about healthy diets is increasing around theworld, there has been increasing demand for miso, soy sauce, natto and other fermented foods indispensable inJapanese foods in and outside Japan, which creates a need for detailed information on these fermented foods.
Under such circumstances, this booklet was compiled to help people understand Japanese fermentation culture byclearly explaining the basics, history, and culture of Japanese fermented foods and typical Japanese fermented
foods from a variety of perspectives, and also explaining its differences from fermentation cultures outside Japan.
We hope that this booklet will be read by more people and help to protect and hand down Japan’s unique fermented
food culture, enhance recognition of various Japanese food cultures, and expand exports of agricultural, forestry,
fishery and food products made in Japan.
March 2023 Ministry of Agriculture, Forestry and Fisheries_Minister’s Secretariat_New
Business and Food Industry Department Food Service Industry and Food Cultures
Division_Food Cultures OfficeInformation about[Traditional Foods in Japan]
This document was created as a content for the Traditional Foods
in Japan, a website run by the Ministry of Agriculture, Forestry
and Fisheries. In the Traditional Foods in Japan, Japanese traditional foods are
divided into 17 categories to help readers to understand them easily.
Information is transmitted through a database of the characteristics, histories
and recipes of selected traditional foods from various regions as well as theregional backgrounds against which such foods were born. Visit this website,and you will want to learn and know about and eat Japanese traditional foods.

1

Photograph:
Shoyu moromi brewing in wooden barrels(Kakizaki Shoyu Shop / Ohnan town, Shimane prefecture)Table of Contents of Japanese Fermented Foods
Chapter 1 Basics of Fermented Foods
1-1 What are fermented foods?
Fermentation and its mechanism/Fermentation and putrefaction
Why are fermented foods tasty?/Rich flavors are a sign of health benefits

3
4

Relationship between region, microorganisms, and fermented food4

Column1-2 Microorganisms that produce fermented foods
Aspergillus oryzae/Yeast
Lactic acid bacteria/Bacillus subtilis natto/Acetic acid bacteria

56Chapter 2 Learn about the History and Culture of Fermented Foods
2-1 History of fermented foods
Birth of fermented foods/Discovery of microorganisms and beginning of zymology

7

2-2 The Japanese and Fermentation
Asian regions with a hishio culture/Koji and the Japanese8

2-3 Diversity of fermentation cultures – Difference between the East and the West
Multiplication-based and addition-based fermentation cultures
Column99Tradition of fermentation in Japan

Chapter 3 Learn about Typical Japanese Fermented Foods
3-1 Fermented seasonings and sakeMiso(Soy paste)
Shoyu(Soy sauce)
Sake
Column10
12
14

Tips for exporting fermented foods shared by a long-established soy sauce brewery

14

3-2 Other typical fermented foods
Dried bonito
Natto/Mirin
Vinegar/Pickles
AmazakeColumn

15
16
17
18

Power of fermented seasonings to bring umami out of foodstuffs

18

Chapter 4 Learn about the Science of Fermentation
Bringing Japanese fermentation technologies to the world(Kenji Maehashi, Tokyo University of Agriculture)

How is “oishisa(tastiness)” produced?/“Koji” is the basis for fermentation in Japan
Invisible fermentation and visible fermentation/Spreading Koji technologies acrossthe world
The future created through coexistence with microorganisms
ColumnLearn from wisdom given by fermented foods

Conclusion

19
20
21
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Chapter 1 Basics of Fermented Foods

1-1 What are fermented foods?
Bread, yogurt, miso soup, shoyu, natto, beer, wine, and sake are foods andalcoholic beverages indispensable to our daily diet. They are all fermented
foods. Fermented foods are made from ingredients such as cereals and soybeansby microorganisms invisible to the naked eye, but what kind of phenomenonis fermentation, anyway? Here, the mechanism of fermentation, the difference
between fermentation and rotting, and the tastiness and functionalities offermented foods are explained in detail.

Fermentation andits mechanism
Fermented foods are foods produced
using microorganisms such as molds,
yeasts, and bacteria. Fermentation is aphenomenon in which the growth andactivity of a microorganism in a food causea change in the food components useful tohumans. For example, alcohol and organicacid made from sugar, lactic acid madefrom sugar, and acetic acid made fromalcohol are all products of fermentation.
Enzymes produced by microorganisms
may cause changes in food components.
This is also a kind of fermentation.
Enzymes can decompose rice starch intosugar, and soy protein into amino acids,
which are a component of the umami(savory) taste. However, fermentation does
not always require the involvement of a
microorganism. For example, an enzyme
contained in a food or a food component
may undergo a chemical reaction that
produces a useful component change. Thiskind of change is called “aging,” which isalso a kind of fermentation.
The miso, shoyu, bread, yogurt, wine,and sake that we usually consume are
all foods produced by the action of somemicroorganism. For example, the aging
of miso are proceeded by the action of
enzymes produced by Aspergillus oryzae,a kind of mold. The taste of miso changes
differently depending on the length of
the aging period. Miso, shoyu, sake, andwine are available in various types, whichis largely due to not only ingredients but
also changing the aging period.

Fermentation andputrefaction
When a microorganism causes a change
useful to humans, we call thephenomenon “fermentation,” and when amicroorganism causes a harmful change,
we call the phenomenon “putrefaction.”
Fermentation and putrefaction are
the same phenomenon, and whether
a phenomenon is fermentation or rot
is decided by humans, based only on
whether it is useful or not. If a harmful
microorganism grows in a food, it emits
an unpleasant odor or tastes bitter or
strange. For this reason, we can avoid
the intake of putrefied foods through thesense of taste or smell. The line between
fermentation and rotting is drawn basedon whether the change is favorable to us
or whether it is safe, rather than what
component or microorganism is involvedin the phenomenon. Fermented foods
have been handed down through thegenerations as regional traditions, andthis long experience with these foods
provides evidence that they pose no
threats to our safety.
Why don’t fermented foods easily rot?
In the world of microorganisms, there isa phenomenon called “antagonism.” It isa phenomenon in which when a certain
microorganism becomes dominant inan environment, other microorganisms
can no longer enter the environment.
Fermented foods have a long shelf life

because this antagonism works to prevent
putrefactive bacteria from entering thesystem.
It is believed that rice koji (*1) originatedfrom an event where mold in the air
adhered to steamed rice offered athousehold altars and grew, aided by
the humid climate of Japan. In Western
European and Central Asian regions,where dairy farming was popular and amilk-consuming culture existed, lactic
acid bacteria naturally adhered to milkleft to stand and resulted in lactic acidfermentation, producing yogurt andother dairy products with a good shelflife. Fermentation is closely associatedwith the climate of the region where it
takes place. Which microorganism islikely to grow depends on the region, andhumans have found the characteristics
of microorganisms through experienceand produced region-specific fermented
foods. Fermented foods can be said
to be processed foods produced byskillfully manipulating the technology offermentation.

*1 Rice koji is steamed rice in which Aspergillus
oryzae has been propagated, and is used to produce
various fermented foods such as miso, soy sauce,and sake.

Relationship between microorganisms and fermented food
Ingredient

Microorganism

Fermented food

Wheat

Yeast

Bread

Fruit

Yeast

Wine

Milk

Lactic acid bacteria

Yogurt, cheese, butter

Rice

Aspergillus oryzae,Yeast

Rice wine, shochu, mirin

Soybeans, rice, barley

Aspergillus oryzae

Miso, soy sauce

Rice, fruit

Yeast,Acetic acid bacteria

Rice vinegar, vinegar

3

Chapter 1 Basics of Fermented Foods

Why are fermented foods
tasty?
People enjoy fermented foods for theirtaste and unique scent. Cereals, seafood,and many other ingredients in fermented
foods are highly nutritious, but are lessflavorful eaten plain. However, sake hasa mellow and sweet taste or flavor. Soy
sauce made from wheat and soybeans has
strong umami and a rich flavor. Shio-koji(*2), when used in cooking, adds strong
umami to foodstuffs and makes thenutrients easier to absorb. The processof fermentation decomposes the originalcomponents and makes them easier todigest and absorb. It also produces richly
flavored components and adds to thetastiness of foodstuffs.
Rice and soybeans are rich in starch andprotein, respectively, which actually havelittle taste. The reason that rice tastes a bit
sweet is that the glucose constitutes starch
has a sweet taste. The reason of good tasteof protein-rich meat is that proteins areconstituted of amino acids that have an
umami taste.
The surface of the human tongue hasorgans called taste buds, by which we cansense tastes. Taste buds are a collectionof many taste cells specialized in sensing
tastes, and taste cells have five sensors
to sense sweet, bitter, umami, sour, andsalty tastes. The taste of a food depends
on which sensor is stimulated by the foodcomponents. However, the taste sensors

Columncan sense small molecules, but cannot
sense large molecules such as starch andprotein. The reason that we can taste
strong umami from fermented foods isthat the fermentation decomposes large
molecules contained in ingredients tomake it easier for them to stimulate thetaste sensors.

Rich flavors are a sign ofhealth benefits
Fermented foods are not only tasty but
also highly nutritious. One of the healthcomponents produced by fermentation is
peptides. Protein contained in fermented
food ingredients is decomposed in theprocess of fermentation. Peptides areprotein fragments produced by the
enzymatic decomposition of a protein, andthey have structures containing aminoacid chains. Fermented products containa variety of peptides with different aminoacid sequences, and it has been known thatthe peptides exhibit various physiologicalactivities depending on their structures.
For example, some peptides made frommilk protein by lactic acid bacteria-derived
proteases, which are proteolytic enzymes,
function to regulate blood pressure, andare widely used in foods with a specifichealth use. Peptides with a similar function
are also contained in soy sauce. These
peptides are made from soy protein by
an Aspergillus oryzae-derived enzyme.
Oligosaccharides are made from starchby an Aspergillus oryzae-derived enzyme.
Some oligosaccharides provide nutrition
for intestinal bacteria, and amazake(sweet fermented drink made of rice) andshio-koji, which contain oligosaccharides,
can be expected to improve the intestinal
environment. It is difficult to chemicallydetermine whether a component beneficial
to health was produced by fermentation,
but flavor of the components producedin the process of fermentation can beconsidered as a sign suggesting that somehealth benefit was produced.
Many of the microorganisms involved infermentation have proteolytic enzymes.
Aspergillus oryzae, which is indispensablefor producing Japanese fermented
foods, has a particularly high proteolytic
capacity. The results of genomic analysesof Aspergillus oryzae demonstrated thatit has more than 100 types of proteolytic
enzyme genes.
Fermented foods contain various healthcomponents produced by microorganisms.
Advances in analytical technology
have made it possible to found various
functionalities of substances resulting
from the decomposition or metabolism
of food components during the process of
microbaial growth.

*2 Shio-koji is a fermented seasoning made bymixing rice koji with salt and water to promotesaccharification and maturation. The enzyme
of Aspergillus oryzae increases the umami offoodstuffs or makes them soft.

Relationship between region, microorganisms, and fermented food
wooden barrels by themselves.
The diversity of fermented foods has been nurtured by the climate ofindividual regions and the environments in which they are produced,
and will be handed down by the efforts of people engaged in the
production of fermented products.

The origin of fermented foods depends on various condition, suchas the climate and topological conditions of the region, what kind offood ingredients are produced locally.
For example, “soy sauce brewed in a wooden barrel” using
traditional methods is a region-specific fermented food. The wooden
barrels provide an environment easy for microorganisms to inhabit,
and are used over a long period of time. As a result, microorganisms,
such as lactic acid bacteria or yeast that produce the soy sauce flavor,
suited to the environment of the region or brewery settle in thebarrels. Such microorganisms act to produce the unique soy sauce
flavor of that particular brewery.
It is said that soy sauce made by this method of using wooden barrels
accounts for less than 1% of the entirety of soy sauce production
these days as more efficient methods are preferred. However, theloss of wooden barrels means the loss of the diversity of soy sauce.
Driven by a sense of crisis over the loss of the tradition, brewers in
Shodo-shima Island in the Seto Inland Sea, where brewing using
wooden barrels has traditionally been popular, are working to handdown the technology to the following generations by apprenticing
themselves to a craftsman to learn how to produce and maintain

The soy sauce brewery on Shodo-shima Island. Countless microorganisms, including
yeast and lactic acid bacteria relevant for fermentation, live in the wooden barrels that arevital for brewing.

4

Chapter 1 Basics of Fermented Foods

1-2 Microorganisms that produce

fermented foods

There are countless microorganisms that produce fermented foods. They are involved in fermentation and haveindividual characteristics that work differently from one another, but are common in that they decompose a certain
substance and produce substances useful to humans. Here, we explain typical microorganisms involved in fermentationand their characteristics, as well as the roles they play in the process of fermentation, etc.

Asperugillus oryzae

Genus name:Aspergillus
Typical fungus:Aspergillus oryzae

Mold domesticated over the course of 1000 years
Asperugillus oryzae is a type of moldand is the generic name for filamentous
fungi that are indispensable in Japan’s
food culture. Asperugillus oryzae is usedin many fermented seasonings and foods
originating from Japan, such as miso,
soy sauce, sake, vinegar, mirin (sweet
sake used in cooking), and dried bonito.
In 2006, it was designated as Japan’snational fungus by the Brewing Societyof Japan. Asperugillus molds include not
only Aspergillus oryzae, a typical moldof this genus used in koji for sake, miso,
and rice vinegar, but also other several
kinds used in koji for soy sauce, shochu(distilled spirit), and Awamori (distilled
spirit of Okinawa).

Yeast

Koji is a cereal or legume in which
Asperugillus oryzae has been propagated,
and is available in different types
including: rice koji made of rice, barleykoji made of barley, and bean koji madeof soybeans. Japanese people haveproduced various fermented foods bytaking advantage of koji. There are two
kanji characters for koji: one is 麹 andanother is 糀, where 米 means rice and 花means flower. The latter kanji character
represents white spores of Aspergillus
oryzae propagating on rice like flowers,
and speaks to the unique sensibility ofJapan.
Tane-koji (spore of Aspergillus mold)dealers have existed as a traditional

business in Japan, from which brewers
around the country purchase Tane-koji
to produce koji. Thus, Asperugillus
oryzae has been managed carefully by
specialized dealers and can be said tobe a mold domesticated by humans.
Recently, the results of genomic analysesof Aspergillus oryzae demonstrated that
unlike wild varieties, Aspergillus oryzae
used as Tane-koji do not have genesthat produce poisonous substances. Thisscientifically demonstrates the safety ofkoji, guaranteed by the 1,000-year long
history of Japan’s koji culture.

Genus name:Saccharomyces, Zygosaccharomyces
Typical fungus:Saccharomyces cerevisiae,
Zygosaccharomyces rouxii

Source of the flavors of Japanese foodYeasts are everywhere in the world of
nature: in the air, in the soil, in water,and on the surface of plant leaves andfruits. The yeast that is most widely usedin fermented foods around the world is
Saccharomyces cerevisiae.
Yeasts have a high capacity to change
glucose into alcohol and carbon dioxide.
With this capacity, yeasts are used mainly
to brew beer, wine, sake, and otheralcoholic beverages, and are also used in
the process of bread production to raise
bread dough and produce unique flavors.
Beer and bread, which are made of malt

and flour, respectively, are produced byalmost the same process.
The unique flavor of soy sauce is also
produced by a yeast. Soy sauce contains
a component with a caramel flavor
called HEMF, which characterizes its
flavor. HEMF is a substance produced
from soy sauce components by a yeast.
Consequently, koikuchi soy sauce inparticular, which has been well-fermented
by a yeast, contains a rich amount of
HEMF. This type of yeast is also used
to brew miso, and is salt-tolerant(halotolerant yeast). Halotolerant yeasts,

5

exemplified by Zygosaccharomyces rouxii,
are indispensable for making Japanesesalty fermented seasonings.
Globally, the term yeast generally refers
to bread yeasts, and halotolerant yeasts
are not often used outside Japan. The richflavor of soy sauce produced by Japan’s
own technologies for using yeasts has
been integrated into the everyday life ofJapanese people as an element that makes
Japanese food tasty, and is a flavor that
represents Japan.

Chapter 1 Basics of Fermented Foods

Lacticacid bacteria

Genus name:Lacticaseibacillus, Tetragenococcus
Typical fungus:Lacticasebacillus casei,
Tetragenococcus halophilus

Bacteria with which the history of fermentation began
Lactic acid bacteria is the generic namefor bacteria that consumes sugar to
produce lactic acid, and exist everywherein the world of nature, as with yeasts. It isbelieved that the history of fermentation
begins with livestock milk fermented bylactic acid bacteria thousands of years ago.
Dairy products such as yogurt, cheese, andbutter are produced by adding lactic acid

Bacillus subtilis natto

bacteria to milk to cause fermentation.
Lactic acid bacteria are also indispensablefor producing miso, soy sauce, and pickles.
For example, in the pickle-making process,lactic acid bacteria adhering to the surface
of vegetables take sugar contained in thevegetables, and yeasts adhering to thevegetables also take part in fermentation.
This combination produces flavors

unique to pickles. Tetragenococcus
halophilus is a salt-tolerant lactic acidbacterium that is indispensable for
producing salty fermented foods such as
miso and soy sauce. Lactic acid bacteria
are facultative anaerobic (they dislike
oxygen), and lactic acid fermentation
takes place inside foods.

Genus name:Bacillus
Typical fungus:Bacillus subtilis

Tough bacteria that survive special environments
Bacillus subtilis natto is a bacteriumthat inhabits rice straw, dry grass, andfallen leaves, and has high propagating
power. When exposed to high or
low temperatures, dry conditions,
undernourished, or placed in othersevere environments, it forms a special
cell structure called a spore and goes
into a dormant state. When placed in anenvironment suitable for propagation, thespores can germinate back into vegetative

cells.
A typical fermented food produced by
Bacillus subtilis natto is itohiki (stringy)
natto. The substance that makes viscousitohiki natto is a high polymer comprisedof γ-glutamic acids, a type of amino acid,connected in a specific way, which makes
Japanese natto what it is. The umami ofnatto is produced by a strong enzyme in
Bacillus subtilis natto during fermentation.
When boiled soybeans are packed in

Acetic acid bacteria

Genus name:Acetobacter
Typical fungus:Acetobacter aceti

rice straw and kept at a certain
temperature, Bacillus subtilis natto
inhabiting in the rice straw propagatesand produces highly nutritious itohiki
natto. The wisdom of taking advantageof the characteristics of Bacillus subtilis
natto was discovered through experienceby the Japanese.

Unusual bacteria that like oxygen and alcohol
Acetic acid bacteria is the generic namefor bacteria that change alcohol into acetic
acid, and are indispensable for producing
vinegar. The strong acidic taste and acrid
smell of vinegar come from acetic acid.
Acetic acid bacteria adhere to flowers
or fruits, and float in the air. Generally,
fermentation does not require oxygen, but
acetic acid bacteria cannot grow without
oxygen. Acetic acid bacteria carry out
acetic acid fermentation, in which theyuse oxygen to oxidize alcohol to acetic
acid. Acetic acid bacteria are acid resistantand produce acetic acid to create anacidic environment. This prevents
other microorganisms from entering
the environment and enables dominantfermentation. Japanese rice vinegar ismade by fermenting sake with acetic
acid bacteria. Wine vinegar is made byfermenting wine with acetic acid bacteria.
Komagataeibacter xylinus is a type of

6acetic acid bacteria and forms a thickfilm in the process of fermentation. This
characteristic can be used to make themilky, jelly-like nata de coco, which ismade by fermenting coconut water with K.
xylinus. The solids floating in Kombucha,
a lightly carbonated drink made byfermenting tea, are also made by the samecharacteristic of K. xylinus.

Chapter 2 Learn about the History and Culture of Fermented Foods

2-1 History of fermented foods
It is believed that the world’s first fermented food is a yogurt-like food, made unexpectedly in Central Asia approx. 6,000
years ago from milk left out in a dry grass field. Having obtained knowledge of fermentation, human beings produced
various fermented foods in different countries around the world by taking advantage of the local climate and foodstuffs
grown there through trial-and-error processes. Following the discovery of microorganisms by Leeuwenhoek, a Dutch
lens polisher, in the 17th century, fermented foods underwent a revolution through the power of science. Let’s trace thehistory of fermented foods until this revolution and the discovery of microorganisms.

Birth of fermented foods
Fermented foods can be seen in various
regions around the world, and havebeen produced and developed throughexperience, influenced by the local climate
and the technologies for preserving
foodstuffs grown there. In Europe, where
dairy farming was popular, many of theirfermented foods were made of milk. It
is said that the phenomenon of curdlingmilk was found unexpectedly by a desert
traveler, who noticed that the milk had
curdled in a water flask made of a goatstomach. Europe’s cool climates andabundance of milk lead to the developmentof technologies that make use of thisphenomenon to produce cheese andyogurt. In grape-growing regions, wine wasborn, and in island countries surroundedby the sea, fermented foods using fisheryproducts commonly appeared. In Japan,
where rice growing has been popular,
various fermented foods using rice wereborn.
Ancient Egyptian wall paintings showthat bread making had already takenplace at that time. It is unknown whether
the fermentation there was carried out
intentionally. However, considering thatkneaded flour swells via fermentationby the action of yeast in the air, whichchanges sugar into alcohol and carbon
dioxide, it is supposed that the ancient
Egyptians had naturally experienced thephenomenon of fermentation. It is also
believed that grape juice was naturally
fermented into wine. It can be assumed
that sweet juice left to stand came to
produce alcohol and was found to havea pleasant flavor and make people feelpleasant when drunk, and that is how
alcohol culture was born. It is believedthat wine had already been brewed in
the country of Georgia around 7000 to5000 B.C. Every country in the world
has its own alcohol culture based on the
foodstuffs grown in their local climate.
When wine is fermented with acetic acidbacteria, vinegar can be made. Similarly,

looking at various regions
around the world, regionswith an alcohol culture
produced vinegar madefrom the same foodstuffs
as the alcoholic drinks
they produced.
Originally, fermented
foods were born fromtechniques for preserving
valuable foods. If foodstuffs
are not properly preserved,
putrefactive bacteria grow. Bread making depicted on the tomb of Ramses III (circa 1221-1156 B.C.)
If they are preserved by https://commons.wikimedia.org/wiki/File:Ramses_III_bakery.jpg?uselang=ja
that rot is caused by an invisible factor
adding salt added, the osmotic pressure(microorganisms in the air). He also
effect prevents putrefactive bacteria fromestablished the pasteurization technology
inhabiting the food. However, salt-tolerant
and contributed to the production ofyeast or lactic acid bacteria, which are notsafe-to-drink wine (*2). In addition,commonly seen, can grow in the presence
another of Pasteur’s big achievements isof high salt concentrations, and thus,that he succeeded in separating acetic acidcontinue to carry out fermentation. As
bacteria from wine that turned sour, ora result, a unique flavor that is different
wine vinegar, as the responsible bacteria
from the original foodstuff is produced,
for the first time.
changing the taste. Fermented foods
Koch, a German known to havewere born from these experiences of our
discovered cholera bacteria and tubercle
ancestors.
bacteria, is another great contributor.
Discovery of microorganisms Koch succeeded in separating pathogens
from animals infected with anthrax.
and beginning of zymology
Koch’smethodforseparating
microorganisms has been used as an
In the 17th century, Leeuwenhoek, aimportantmethodinsubsequent
Dutchman, discovered the existence of
microbial studies. Hansen, a Dane, and his
microorganisms. This discovery provided
associates invented a pure culture method
a great opportunity for human beingsfor yeast by applying Pasteur’s theory, andto come to know the involvement
achieved the innovation of separating andof microorganisms in fermentation.
culturing beneficial yeasts for beer
Leeuwenhoek observed various microscopic
production based on this method.
organisms with a microscope he had madeThanks to the discoveries and inventions
himself and shared his findings. Owing toby these great figures, human beings can
his observation, human beings came totoday safely eat fermented foods.
know for the first time that microscopicorganisms exist in the world. This is the*1 A flask with a thin and long neck extending in
beginning of microbiology.
a lateral direction. By bending the neck like a
It is Pasteur, a French microbiologist, whoswan neck in the middle, the flask can prevent
microorganisms in the air from entering it.
greatly contributed to the development of*2 In the presence of alcohol, just keeping grape juice
zymology. Pasteur scientifically explained
at a low temperature for a short period of time hasa bactericidal effect. This technology is the samethe phenomenon of fermentation. He
as hiire, a process in brewing sake in Japan where
demonstrated in an experiment using a
the sake is gently heated to sterilize the liquid
before preservation, and it is believed that this hiirewell-known swan neck flask (*1) that rot isprocess had taken place 300 years before Pasteur’s
not caused without an external factor anddiscovery.

7

Chapter 2 Learn about the History and Culture of Fermented Foods

2-2 The Japanese andFermentation

Japan is sometimes called one of the world’s largest producers of fermented foods. Japan
has a unique fermentation culture born from the fusion of a humid climate specific to
East Asia, the varied topographies and abundant nature surrounded on all sides by thesea, and the sharp eyes of our ancestors. This unique culture is based on Aspergillus
oryzae, a mystical mold, and koji made by this mold. Here, let’s look at the backgroundand characteristics of Japanese fermentation culture from a historic perspective.

Asian regions with a hishio
cultureFermentation technologies introduced
from China have played an important rolein the background of Japan’s fermentation
culture. Soybeans originated in China,
where there are many soybean-based
fermented foods. Around 700 B.C. (in theZhuo Dynasty period), [hishio], which
are salted and fermented foods and isconsidered to be the original form of soy
sauce, had already been made (Hishio isgenerally written as “醤” in kanji, andis also written as “比之保”). There aredifferent types of hishio: kusabishio(salted and fermented vegetables),kokubishio (salted and fermented cereals),
uobishio (salted and fermented fishes),
and shishibishio (salted and fermentedmeat). Basically, when foodstuffs are
salted, water is carried out of the cells by
the osmotic effect of salt. It is thoughtthat these salted foodstuffs would begin
to ferment with time and the resultant
infusion had been used as a fermented
seasoning. Then, kusabishio evolved into
pickle-like foods and kokubishio into soy
sauce and miso.
It is said that hishio was introduced
to Japan around the 4th to 6th century.
Miso was called “hishio” and was likesalted soybeans at that time. Rice miso
was born by using koji, and then spread
across the country. The origin of the word
[miso] was written as [未醤] in kanji. “未” means yet-to-be, and [未醤] means
yet-to-be-completed [hishio]. It wasprobably changed to [味曾] and then to thepresent kanji characters [味噌]. Soy sauce
was the liquid collected from the surfaceof miso (called “tamari”) at that time,
and was a by-product of making miso.
This liquid was developed into soy sauce
using koji. Uobishio was made by salting
small fishes and fermenting them overa long period of time into a liquid, andproduction declined since after the Heianera. However, some uobishio products,
such as Shotsuru in Akita Prefecture,
Ishiru in Ishikawa Prefecture, and Ikanago
soy sauce in Kagawa Prefecture, have been
handed down until today.
In not only Japan but also other Asian
regions based on rice farming and fish

eating, kokubishio and uobishio had beenused since a long time ago. Fermented
seasonings similar to miso that have been
handed down until today include Chinesehishio seasonings such as doubanjiang(chili bean sauce) and tianmianjiang(sweet bean paste), and South Korean
gochujang (Korean red chili paste). Thainam-pla and Vietnamese nuoc mam arekinds of uobishio. In addition to Japanese
soy sauce and miso, these are seasonings
that exactly represent Asian regions witha fermentation culture.

Koji and the Japanese
In Japan, where rice farming was
popular, fermented foods using rice
were developed using fermentation
technologies introduced from China.
The underlying technology for producing
these fermented foods is [koji], and ricekoji, made of rice, was used to make sakeand soy sauce. The process of making
soy sauce, miso, sake, vinegar, or otherfermented foods by applying fermentation
is called [brewing], and Japanese brewing
technologies are characterized by its use ofkoji. The importance of koji in the processof brewing can be seen in the proceduresfor brewing soy sauce, miso, and sake. In
brewing soy sauce, [koji making comes
first, stirring comes second, and heating
comes third]. In brewing miso, [kojimaking comes first, boiling comes second,and brewing comes third]. In brewing
sake, [koji making comes first, sake mash
making comes second, and brewing comes
third]. Koji is an epoch-making invention
by Japan, and forms the backbone ofJapan’s fermentation culture.
Originally, [麹], the kanji character for
koji, was created in China, and refers torice, barley, wheat, soybeans, or othercereals inoculated with a fermentation
mold. In Japan, the Japanese original
kanji [糀] is also used, where “米” means
rice, and refers to rice inoculated withAspergillus oryzae. This provides evidence
that rice koji was born in Japan.
Koji in China is made by grinding wheat,barley, or other cereals into powder,kneading it together with water, molding
the mixture into a mochi (rice cake) shape,and cultivating a fermentation

8

Inside the koji room, where koji is madeCourtesy of: Fukuoka Soy Sauce Shop
(Iga City, Mie Prefecture)mold, which may be Rhizopus or mucor
inhabiting in China. For this reason, thiskoji is called [mochi koji]. In Japan, on
the other hand, Aspergillus oryzae is used
for koji. Aspergillus oryzae is cultivatedon rice grains to make bara (granular)
koji. This difference is that bara koji
takes advantage of the characteristics ofthe fungus used. The mochi koji style issuitable for Rhizopus and other molds ofthe same genus, which grows its elongatedroots deep into the mochi, drawing
nutrition from it and easily propagating
inside the mochi. However, Aspergillus
oryzae cannot easily propagate on mochi.
Aspergillus oryzae likes rice, and attaches
to the rice surface and grows elongatedspores there rather than elongatedroots deep into the rice. In Japan, thebara koji style takes advantage of thesecharacteristics of the mold to develop amethod to make koji from rice grains.
In Japan, efforts have been made topursue safer and more stable fermentation.
As a result, our ancestors found that to
make quality koji, it was important touse a quality fungus, and then, [seed koji
dealers] appeared as a type of business
which handled quality Aspergillus oryzae.
If wood ash is added to Aspergillus oryzae
spores, the potassium in charcoal helps
the fungus to propagate while undesirable
bacteria that dislike alkaline environments
can be controlled. Our ancestors foundthat pure Aspergillus oryzae spores could
be obtained by this method based on theknowledge of these characteristics of thefungus and charcoal.
Aspergillus oryzae sp. molds in thenatural world are toxic. Experientially,
our ancestors stored quality Aspergillus
oryzae used for producing sake, andsucceeded in growing it as a pure culture
and successfully separating the safe
Aspergillus oryzae. This is how Aspergillus
oryzae was [domesticated], and only
safe, beneficial fungi came to be used
for producing fermented foods in Japan.
Technologies that form the basis fortoday’s biotechnologies have been handed
down to us continuously since ancient
times in Japan.

Chapter 2 Learn about the History and Culture of Fermented Foods

2-3 Diversity of fermentation cultures –Difference between the East and the West

Fermentation is closely related to the climate of the region, the microorganisms inhabiting it, and foodstuffs harvested
there. Bread, cheese, wine, and Japanese soy sauce, miso, and sake are all fermented foods, but are made by using
different microorganisms and different methods. Japanese miso and soy sauce were developed based on fermentation
technologies introduced from China, and are deeply related to Chinese fermentation culture. Different countries makedifferent fermented foods, but the fermentation cultures behind them can be divided roughly into the fermentation
culture of the East and that of the West, which have their own respective characteristics.

Multiplication-based
andaddition-based fermentation
cultures
The eastern areas of the world, including
East Asia’s China and Southeast Asia,
has hot and humid climates, where
putrefactive bacteria easily grow andfoodstuffs easily rot. For this reason,
the technology of salting foodstuffs,
such as vegetables and fishery products,
had developed to preserve them for
longer periods of time. During long-timepreservation, fermentation is started
by fungi or bacteria that act even in
the presence of salt, such as lactic acidbacteria. Various pickles, such as Japanese
pickles, Chinese Szechuan pickles, andKorean kimchi pickles, and various kindsof fish sauce (present form of uobishio)
used in Southeast Asia are fermented
foods made by combining salting andfermentation.
What is also important to note about
fermentation in the East is fermentation
using [molds]. The East has hot and humid
climates that are suitable for molds topropagate, and is abundant with rice,barley, wheat, soybeans, and other cereals
molds are fond of. Fermented foods madeColumnby using molds can be found in each ofthese regions, such as cereal-based
alcoholic beverages including sake,
Shaoxing rice wine, and makgeolli, andseasonings
includingdoubanjiang,
gochujang, soy sauce, and miso. By
involving molds as well as other fungi andbacteria such as lactic acid bacteria, acetic
acid bacteria, and yeast in fermentation,unique, complex, and sometimes peculiar
tastes that combine saltiness, sourness,and umami are produced.
On the other hand, in the western areasof the world, including Europe and theareas around the Mediterranean Sea,
which have relatively dry climates, there
was no need to salt foodstuffs to prevent
putrefactive bacteria from growing.
Typical fermented foods made in theseareas include bread and beer made from
wheat and barley, respectively, alcohol
beverages made from fruits, and dairy
products such as cheese and yogurt, andthe production of these foods involves
relatively fewer kinds of fungi and bacteria
and is based on simple fermentation. For
example, when the sugar in milk is
decomposed by lactic acid bacteria, sour
lactic acid is produced. When the lactic
acid is left to stand, it curdles into yogurt.

Similarly, when the sugar in grapes ischanged by yeast to produce alcohol, wine
can be made. By using a certain fungus
or bacterium with a certain foodstuff,
a certain fermented food can be made.
Based on this idea, clear and theoreticalfermentation cultures have developed.
Generally, food cultures in the West are
based on the idea of extracting the positive
qualities of foodstuffs and blending them,which can be said as the idea of addition.
On the other hand, food cultures in the
East are based on the idea of making themost of or bringing out the natural tastes
and flavors of foodstuffs, and involving
different kinds of fungi and bacteria in theprocess, which can be said as the idea ofmultiplication. People in the West may
think that fermentation cultures in the
East are kind of mysterious, especially theway in which the molds used are largely
invisible. This shows that fermented foods
are inseparable from the climates where
they are produced. Savor wine and feel the
climate of the region where it was made.
Savor pickles and think about the livingof people in the region where they were
made. Every fermented food has a story.

Tradition of fermentation in Japan
which god was the father, paddy fields were made and sake wasbrewed. When offered the sake, the child poured it for one of gods
gathered. Thus, they could find the father].
[Kojiki (Records of Ancient Matters)] has a story saying, [Susanoo
no Mikoto, a god, let Yamata no Orochi (big snake with eight heads),
which was extremely fond of sake, drink sake to eliminate it. The god
cut off the eight heads and tail of the mortally drunk and sleeping
big snake]. The sake that the snake drank was [Yashiori no Sake],
which is written as “八塩折之酒” in kanji. “八” means many, “塩”
means matured moromi soup, and “折” means repeat. A descriptionthat the process of brewing was repeated 8 times can be found in thehistory book, and it can be assumed that the sake was very tasty. Koji
in Japan has such an ancient origin, and has been handed down theages, which lets us realize how great fermentation is.

Microorganisms act on materials to change them into othermaterials beneficial to human beings. This is fermentation.
Fermentation in Japan has a deep history, and its strong footprints
have been left in Japan’s oldest history books.
[Harima no Kuni Fudoki (topography of Harima Province)] has astory saying, [Dried boiled rice offered to Iwa no Okami (great god)
got wet and moldy. Sake made by brewing it was presented as niwaki(sacred sake), and a drinking party was held]. This story is considered
to be the most widely believed theory about the origin of koji used inJapan. The setting of this story is believed to be present Niwata-jinja
Shrine located in Shiso City, Hyogo Prefecture, and legend has it thatsake was made using warm water present behind the main shrine.
The same book also has a story saying, [Michinushihime no Mikoto,a goddess, gave birth to a child whose father was unknown. To find9

Chapter 3 Learn about Typical Japanese Fermented Foods

3-1 Fermented seasonings and sake
Miso and soy sauce are two seasonings indispensable to dining tables in Japan. They are both fermented seasonings thatare made mainly of soybeans and originated from technologies introduced from the Chinese continent. Over their long
histories, various kinds of miso and soy sauce have been produced to suit the climates and taste preferences of various
regions in Japan, and they are today world-renowned seasonings. Sake, which is called “seishu” under the Liquor Tax Act, isbased on the Japanese people’s rice-eating culture and Aspergillus oryzae, which are combined with delicate technologies
for manipulating microorganisms that our ancestors developed. It is worthy to be called the [national drink] of Japan. Here,details about these fermented products, including their histories and methods for producing them, are introduced.

Miso (Soy paste)
Infinite variations produced by
the different climates of different
regions
Miso is a solid salty fermented seasoning
made by fermenting soybeans in thepresence of a high concentration of salt. In
the Japanese Agricultural Standards (Acton Japanese Agricultural Standards) (*),
miso is defined as a [semisolid material
made by adding koji based on rice,barley, or another cereal (or koji made ofsoybeans) to steamed soybeans, mixing
salt, and allowing the mixture to ferment
and mature].

The history of miso
It is believed that miso originated fromhishio and kuki (boiled and mashedsoybeans with added salt), which havebeen known from ancient times in China.
Hishio refers to salted and fermented
foods. There are different types ofhishio, such as kusabishio (salted andfermented vegetables), uobishio (salted
and fermented fishery products), andshishibishio (salted and fermented beef,
pork, etc.). Asia, with its rice-farming
culture, saw the development ofkokubishio (salted and fermented
beans or soybeans). Typical seasonings
that originated from hishio include
doubanjiang (chili bean sauce) and touchi(fermented black beans) in China andgochujang (Korean red chili paste) in South
Korea.
In Japan, a food modeled after hishio andkuki was introduced through the Korean
Peninsula approx. 1300 years ago. It was
like today’s soybean miso, represented
by the kanji characters “未醤.” This isbelieved to be the origin of miso. It is said
that the kanji characters “味噌,” which
is pronounced “miso,” started to be usedin the Heian era. The kanji character [噌] was created in Japan, and is only usedin the kanji characters “味噌,” indicatingthat miso is Japan’s own food. After that,Japan’s own rice miso using rice koji wasdeveloped in the Japanese rice-eating
culture, and spread across the country.
In the Heian era (794 – 1185), miso
was eaten as-is, as a side dish, or used
as a seasoning put on tofu (bean curd)or vegetables, and was considered as an
expensive food habitually eaten by theupper-class. This kind of miso is called[name miso (miso eaten as it is)] or [okazu
miso (miso eaten as a side dish)], and still
today, there are various kinds of miso
eaten in this way. Popular ones include
kinzanji miso, tai miso, iriko miso, andsankai miso. These are regional specialties
or they reflect regional eating habits.
Miso soup was invented in the Kamakuraera (1185 – 1333). Miso soup is said tobe a great product invented by Japanesefood culture. Unlike soup popular in othercountries, miso soup is not eaten alone
but always eaten with rice. [Ichiju-issai],

the one soup plus one dish (or three-dish)meal style comprised of cooked
miscellaneous cereals, miso soup, and apickle, was established in this era.
In the Sengoku period (1467 – 1573),
military commanders around the country
used miso as army provisions because of its
good keeping quality and nutritiousness,and thus, miso came to be made widelyaround the country under the leadershipof feudal loads. [Oensogura], built in the
castle town of Sendai Aoba by Masamune
Date, is believed to be Japan’s first miso
factory. The taste of miso produced in thefactory has been handed down as [Sendaimiso]. Shingen Takeda, who built the basis
for [Shinshu miso], and Ieyasu Tokugawa,the founder of the Edo Shogunate, are
known to have been extremely fond of
miso soup, which helped to develop themiso culture in Edo.
*1 This is a system based on the Act on Japanese

Agricultural Standards (“JAS Act”), an act enacted
in order for the Japanese government to specify
standards on foods and agricultural, forestry, andmarine products and on methods for handlingthese products (“JAS standards”). Under thissystem, food products and agricultural, forestry,
and marine products can be labelled with a
JAS mark, which certificates that they satisfy
JAS standards, or advertisements of businesses
handling these products can contain a JAS mark.

Process of producing rice miso and barley miso
Making koji
Steam rice or barley

Different kinds of miso with different
tastes, colors, and many othercharacteristics are produced
depending on the length of theWater and salt
maturing period.

Rice koji or barley koji

Fermentation
andAspergillus oryzae
Steam and mash soybeansmaturation
Lactic acid bacteria
Yeast

10

Miso

Chapter 3 Learn about Typical Japanese Fermented Foods

At least 1300 years have passed sincehishio and kuki were introduced, during
which various kinds of miso that use
or reflect different local ingredients,
climates, and eating habits in different
regions in Japan have been produced, andhave played a great role in creating local
food cultures.

Variety of miso
Miso is roughly divided into four kinds:[rice miso], [barley miso], [soybean
miso], and [blended miso]. These arecategorized into [ordinary miso]. [Ricemiso] is classified into the three kindsof ama (strongly sweet) miso, amakuchi(moderately sweet) miso, and karakuchi(salty) miso by the amount of koji and salt
used, and into three more kinds by color:white miso, red miso, and light-coloredmiso (medium-colored miso).
Ama miso is made in a short period of 5 to
20 days, and is very sweet due to the sugar
content derived from rice koji. Ama miso
is divided into two types by color: whiteama miso and red ama miso, which is dueto the difference in the method used forprocessing the soybeans.
[Red ama miso] is brownish-red, glossy
miso represented by [Edo-style ama miso],and has a unique flavor produced by the
combination of the savory aromas of koji
and soybeans. On the other hand, [whiteama miso] is a vivid light yellowish-white,
and is characterized by a unique flavor thatcomes from rice koji. [Saikyo miso] madein Kyoto is typical miso of this kind, and[Sanuki miso] made in Kagawa Prefectureand [Fuchu miso] made in Hiroshima
Prefecture are also well-known miso of
this kind. Ama miso is commonly used formiso-based dishes or miso sauce rather
than for miso soup, and has a short shelflife.

Amakuchi miso is also called “chuama(medium-sweet) miso.” [Aijiro miso]
made in Shizuoka Prefecture and [Gozenmiso] made in Tokushima Prefecture are
well-known miso of this kind, and miso of
this kind is also produced in the Setouchi
seashore region.
Karakuchi miso is made over a long
brewing period, and the rice miso thatis produced in the largest amounts
is karakuchi miso. Karakuchi miso
comes in light and red colors. The color
shade depends on the method used forprocessing the soybeans used as theingredient and the flavor depends on thelength of the aging period. Represented by[Shinshu miso], light-colored karakuchi
miso is bright light yellow, and has arefreshing flavor unique to fermentation,
and a light and plain taste. Represented
by [Sendai miso], red karakuchi miso has
a vivid brownish-red color and a pleasantflavor resulting from a long period of
aging, and presents a robust and strong
taste produced by a harmony of umami
and saltiness.
[Barley miso], which is also called “inaka(country-style) miso,” was originally madeby farmers for their own consumption,and its industrial production takes place inlimited areas such as the Kyushu, Shikoku,
and Chugoku regions and some parts of the
Kanto region.
It is [soybean miso] that is made the same
way as the earliest kinds of miso, and it
is considered the original form of miso.
Soybean miso does not use rice or barley,
and is made by turning all ingredientsoybeans into koji. Other kinds of miso
use bara (granular) koji while soybean
miso uses molded koji made by pounding
steamed soybeans into a ball. It contains
salt at a concentration of 10% to 11%,which is somewhat lower for salty miso. It
is dark brownish-red, and presents a

unique flavor, with a robust and richumami and a slightly astringent taste.
Soybean miso is produced only in Aichi
Prefecture, Gifu Prefecture, and Mie
Prefecture, and miso produced there isnamed “Haccho miso,” “Nagoya miso,”“Sanshu miso,” “Tamari miso,” etc.
In addition to these three kinds of miso,
other kinds of miso collectively called
blended miso are also subject to thequality labeling standards under the Act on
Japanese Agricultural Standards. Blended
miso includes miso made by mixing ricemiso, barley miso, and/or soybean miso
as well as miso made by mixing ricekoji, barley koji, and/or soybean koji andbrewing the mixture.
Miso other than ordinary miso is called[processed miso], and is divided into
[brewed name miso], which includes
Kinzanji miso and hishio miso, and[processed name miso], which includes
tekka miso, tai miso, and yuzu miso,
according to the production method.
[Brewed name miso] is made from dehulledsoybeans, barley, salt, vegetables, andother ingredients by fermentation andmaturation. [Processed name miso] ismade by adding other ingredients, suchas vegetables, fishery products, sugar, andspices, to ordinary miso and heating andkneading the mixture, and is available inmany varieties.

Soybean koji, vital for making soybean miso
Courtesy of: Marukajozo (Toyota City, Aichi Prefecture)

Classification of miso and major areas of production
Type of miso

Classification bytaste or color

Typical miso colors

Percentage
Salt
concentrationof koji

5~7

Kinki region, Chugoku region, Setouchi

12~20

5~7

Tokyo

8~15

7~12

Shizuoka, Kyushu

Red

10~15

11~13

Tokushima and other regions

Light-colored

5~10

11~13

Kanto-Koshinetsu, Hokuriku and other regions of the country

Red

5~10

11~13

Kanto-Koshinetsu, Tohoku region and other regions of the country

Amakuchi Light-colored
miso

15~25

9~11

Kyushu, coastal areas of Japan Sea in the
Chugoku region

Karakuchi
miso

Red

8~15

11~13

Kyushu, Shikoku, northern part of Kanto

Soybean miso Karakuchi
miso

Red

Whole
quantity

10~12

Chukyo (Aichi, Mie, and Gifu Prefectures)

Ama misoRice miso

15~30

Red

Amakuchi Light-coloredmiso
Karakuchi
miso

Barley misoWhite

Major areas of production

Rice miso(salty/red)

Rice miso(light-colored)

Rice miso(sweet/white)

Soybean miso

[Nihon no Dentoshoku Jiten] (Encyclopedia of Japanese Traditional Foods)(Edited by Nihon Dento Shokuhin Kenkyukai (study group),
Asakura Publishing Co., Ltd.)The figure in page 249 was partially changed.

11

Barley misoChapter 3 Learn about Typical Japanese Fermented Foods

Shoyu (Soy sauce)
Magical liquid that contains 300
kinds of flavors in a single drop
Shoyu is a fermented seasoning in theform of a clear liquid. It is made by soaking
koji made of soybeans in salt water toallow fermentation and maturation to takeplace. Since shoyu is rich in glutamic acid,an umami component, and other aminoacids, it can be used in cooking to add asalty taste as well as umami to dishes andmake them tasty. Of these different kindsof shoyu, koikuchi shoyu has the richest
flavor. There are more than 300 known
flavor components of shoyu, which include
caramel, vanilla, rose flower, banana,apple, matsutake mushroom, smoky
flavors, and many other flavors. Pouring
only a single drop of shoyu on a dish wraps
it in a soft shoyu flavor. The pleasant flavor
increases the tastiness of the dish. Shoyu
contains flavor elements from various
foodstuffs, and thus goes well with various
dish flavors.

The history of shoyu
Shoyu originated from hishio (jiang in
Chinese) and kuki (chi in Chinese) in the
Qin period in China or as early as over 2000
years ago. In [Qi Min Yao Shu] written in

Shoyu moromi Courtesy: Fukuoka Soy Sauce Shop
(Iga City, Mie Prefecture)[Moromi] is created by combining salt and water to koji.
Salt-tolerant lactic acid and yeast grow andfermentation occurs to develop the unique flavor of shoyu.

the early 6th century, the technique for
producing the original form of shoyu, or
the supernatant of mamebishio (salted andfermented soybeans) called “Dou Jiang
Qing”, is described.
Although there are various stories
regarding the origin of shoyu in Japan, it issaid that it was introduced together with
Buddhism. According to the Taiho Code(701), it is recorded that various kinds ofhishio were made of soybeans in Shoin, afacility for producing and storing hishio,
established by the Imperial Household
Department. [Engishiki], a book for codesand procedures on national rites andprayers written in the Heian era, which isapprox. 200 years after that, refers to soup
separated from hishio called “saisho,”which is today’s tamari (thick) shoyu.
On the other hand, there is another story
that shoyu originated from tamari soupfrom miso spread by a Zen priest named
Kakushin in the Kamakura era. Kakushin
went to China, practiced ascetic exercisesin the Kinzan-ji Temple, and learned how
to produce miso. After coming back toJapan, he founded a temple, which later
became Kokoku-ji Temple, in Yurasho,
Kii Province, and spread the method
for producing miso while performing
missionary work. It is also said that thesoup accumulated at the bottoms of vatsin the process of miso production was
found to be tasty and suitable for flavoring
simmered dishes, and this soup is theorigin of shoyu.
In the Muromachi era (1336 – 1573),
industrial production of shoyu began in
the Kansai region, which was the center ofculture at that time. Until the beginningof the Edo era, shoyu made in the Kansai
region was called kudari shoyu (shoyu
brought from the capital), and became
available in Edo. With the developmentof the city of Edo, Edo-style culture
emerged, and koikuchi (dark-colored)
shoyu that goes with tempura, eel kabayaki(broiled/grilled eels basted with a sweet
sauce), foods boiled down in shoyu, andother Edo-style dishes was invented. Then,koikuchi shoyu replaced kudari shoyu,
which had accounted for the majority of

Shoyu blends well with foods, whether through cooking orby dipping. It also works to eliminate the fishy scent of raw
seafood.

shoyu in Edo until then, and became one of
Edo’s major seasonings.
In the Kanto region, Noda and Choshi
in Chiba Prefecture developed as Japan’slargest producers of shoyu partly due totheir convenience for transportation andother favorable geographical conditions.
Shoyu brewers were concentrated incertain production areas such as Noda,
Choshi, Tatsuno (Hyogo Prefecture), andShodo-shima Island (Kagawa Prefecture),
and competed with each other on qualityand developed shoyu into the staple ofJapan’s food industry that it is known fortoday.
Shoyu is sold not only in Japan but also
in more than 100 countries around theworld, and now is one of the world’s
best-known seasonings. For example, theword soybean originated from shoyu bean.
It is also said that Louis XIV, the former
king of France, who was well-known as agastronome, habitually used shoyu as asecret ingredient.
Shoyu has been internationalized owing
to efforts of leading shoyu manufacturers
including Kikkoman Corporation, which
penetrated the U.S. market earlier thanothers. Shoyu became familiar to JapaneseAmericans, American soldiers who was
stationed in Japan and then returned to
the U.S., and other people living there,
and came into general use in the country.
Shoyu was also integrated into American
food culture as the base for teriyaki sauce.

Variety of shoyu
Under the Act on Japanese AgriculturalStandards, shoyu is divided into five kinds:

Process of producing koikuchi soy sauce
Making koji
Roast and grind wheat

蒸す
Steam soybeans

Fermentation

MoromiSoy sauce koji

Aspergillus oryzae

maturation

Water
and salt Lactic acid bacteria
Yeast

Different kinds of soy sauce withdifferent tastes, colors, and many othercharacteristics are produced dependingon the length of the maturing period.

Soy sauce
12

Pressing

andSterilizationby heating

Chapter 3 Learn about Typical Japanese Fermented Foods

koikuchi (dark-colored) shoyu, usukuchi(light-colored) shoyu, tamari (thick)shoyu, saishikomi shoyu (shoyu brewed
in another finished shoyu product), andwhite shoyu.
Koikuchi shoyu accounts for more than
80% of shoyu produced across the country,
and thus, shoyu generally refers to
koikuchi shoyu. Koikuchi shoyu is made bycultivating Aspergillus oryzae in a mixtureof soybeans and wheat in equal amounts to
produce shoyu koji, and soaking it in salt
water to allow fermentation to take place.
The enzymes in Aspergillus oryzae cause
the ingredients to decompose, and the
shoyu koji melts into a sticky substance.
Then, umami is produced. During thisprocess, lactic acid bacteria grow and yeast
carry out alcohol fermentation, producing
a rich flavor.
Usukuchi shoyu is made by using a
mixture of soybeans and wheat in equalamounts as the ingredients of shoyu
koji. In the production process, steamed
rice or amazake made of steamed riceis added to prevent the shoyu color
from becoming dark. Thus, usukuchi
shoyu is characterized by the production
method making the shoyu color as light as
possible. To slow down the fermentationand maturation speed, 10% more salt thanfor koikuchi shoyu is used. Usukuchi
shoyu was developed with the intent tokeep the natural flavors and colors offoodstuffs used in dishes. It originated in
Tatsuno, Hyogo Prefecture, and developed
in close connection with kaiseki ryori (teaceremony dishes), vegetarian dishes, andother traditional Japanese dishes.
Tamari shoyu is made by using shoyu kojithat does not use wheat but is made almost
only of soybeans. Tamari shoyu originatedin the Tokai region of Aichi, Gifu, and Mie
Prefectures, and tamari shoyu made in
the Tokai and Hokuriku regions accounts
nearly 80% of the nationwide shipment
volume. Tamari shoyu requires a longer
maturation period than koikuchi shoyu,
and has a rich and unique flavor. It is often
used as shoyu for sashimi or kabayaki, andalso used widely to flavor a variety of foods
such as rice snacks, foods boiled down inshoyu, and noodle soup.
Saishikomi shoyu is shoyu made by using
a mixture of soybeans and wheat in equalamounts as the ingredient of shoyu koji,
adding kiage shoyu (shoyu squeezed frommoromi) instead of salt water in moromi,
and brewing the moromi. Saishikomi
shoyu originated from Kanro (nectar)
shoyu from the Yanai region, Yamaguchi
Prefecture. Since kiage shoyu is added in

the production process, saishikomi shoyu
uses slightly less salt than koikuchi shoyu,
has a thick taste and color, and is viscous.
It is used as shoyu for sushi or sashimi orin sauces for eels.
White shoyu is made by using a mixture ofa small amount of soybeans and wheat as
the ingredient of shoyu koji, and strongly
controlling the appearance so that it looks
less dark-colored and less glossy throughthe production process. It originated in
Hekinan City, Aichi Prefecture approx.
200 years ago, and is still now producedin this region. It has an extremely lightcolor, tastes very sweet, and presents a
unique koji flavor and amazake flavor. It
is used for foods that should be plain or
light-colored. For example, it is used for
hot pot dishes, soup dishes, and needle
soup or to process confectioneries, ricecrackers, fish sausages, and pickles.

Koji for white shoyu
Courtesy of: Hichifukujozo (Hekinan City, Aichi Prefecture)

Characteristics and regions of production of shoyu

TypeProduction method and characteristics

RegionKoikuchi shoyu

Equal amounts of soybeans and wheat are mixed to create shoyu koji, which is soakedin salt water 1 to 1.2 times the volume of the koji to allow fermentation to take place.
The fermentation and maturing period are approximately eight months. The moromi isstirred occasionally during fermentation to encourage yeast growth. After fermentationand maturing is complete, moromi is pressed to squeeze kiage shoyu, which is heatsterilized at 85℃ or higher to create shoyu products.
This shoyu is the most flavorful as the yeast has been fermented very well.

Usukuchi shoyu

Usukuchi shoyu is made by using soybeans and wheat as the ingredients of shoyu koji.
Amazake is added to make the shoyu taste mild. The salt concentration is relatively
high, to suppress fermentation, and some ideas are introduced in the production
process to prevent the shoyu color from becoming dark.
To make good use of the original colors and flavors of foodstuffs, usukuchi shoyu has amild color, umami, and flavor, but it contains more salt than koikuchi shoyu.

Kansai region

Tamari shoyu

Tamari shoyu is made by using soybeans and a very slight amount of wheat as theingredients. Soybeans are mashed into a sphere, from which koji is made. The koji
is then fermented in a small amount of salt water. Tamari shoyu requires a longer
maturing period than koikuchi shoyu.
Tamari shoyu is rich in umami components, and has a rich, unique flavor.
It boasts a rich flavor that works to eliminate the raw smell of fish and meat.

(Aichi, Gifu, andVarious regionsof the country

Tokai region
Mie Prefectures)

Saishikomi
shoyu

Saishikomi shoyu is made by mixing equal amounts of soybeans and wheat to makeshoyu koji and brewing (maturing) it in kiage shoyu rather than in salt water for a long
period of time (1.5 to 2 years or longer).
Saishikomi shoyu has a rich flavor, color, and umami.

Yamaguchi
Prefecture, Saninregion to
Kyushu region

White shoyu

White shoyu is made by mixing wheat and soybeans at a ratio of approx. 9:1 to makeshoyu koji and brewing it in water with a relatively high concentration of salt. The
fermentation and maturing period is approx. 3 months. The process for coloring the
shoyu does not take place or is completed in a very short period of time.
White shoyu is light-colored, has mild umami and is not so robust, but has a strong
sweet taste and flavor that come from koji. It is suitable for osuimono and chawanmushi(savory steamed egg custard).

Aichi Prefecture

13

Color

Chapter 3 Learn about Typical Japanese Fermented Foods

Sake
Productofforskillfully
microorganisms

biotechnology
manipulating

Alcoholic beverages are made from asugar-containing foodstuffs by alcoholic
fermentation using a yeast. Wine is madeby fermenting grape juice with a yeast, andwhat is important for wine is the qualityof grapes used as the ingredient. Beer ismade by saccharifying barley with malt
and then fermenting it with a yeast. On
the other hand, sake, which is the national
drink of Japan and is called “seishu” (clearsake) under the Liquor Tax Act, can besaid to be an alcoholic beverage madeby manipulating microorganisms moreskillfully.
The basic method for producing sakeis as follows: First, steam appropriately
polished rice, and cultivate Aspergillus
oryzae on it to make rice koji. Add a yeast
to small amounts of the rice koji andwater, add a small amount of steamed
rice, and cultivate the microorganism tomake sake mash. Further add steamed
rice, rice koji, and water to the sake mashin three parts, and allow the mixture to
brew and ferment at a low temperature.
Then, the rice starch is decomposed by
the Aspergillus oryzae-derived amylase
into glucose (saccharification), and theColumnyeast carries out alcoholic fermentation
to finally produce sake. The yeast isallowed to carry out fermentation at a
low temperature to keep a good balance
between starch saccharification and yeast
fermentation. There are two types ofsake mash: one is yamahaimoto, which ismade by adding yeast after wild lactic acidbacteria have grown well after brewing,
and another is sokujomoto, which is madeby adding commercially available lactic
acid and yeast to morimi at the sametime during brewing. Both types of sakemash were originated from the wisdom ofallowing yeast to carry out fermentation
in a pure environment by weeding out
bacteria moving from koji, or brewing
water, to moromi.
The alcohol concentrations of beer
and wine are approx. 5% and 12%,
respectively, while that of sake is ashigh as 20% (however, the alcohol
concentrations of sake products areadjusted and decreased to approx. 15%).
The high alcohol concentrations of sakeare due to its specific production method,where high-concentration brewing usinga very small amount of water or only a
1.2–1.3 water to rice ratio takes place, andthe yeast is allowed to continue alcoholic
fermentation by adding steamed rice,
rice koji, and other ingredients in threeparts (three-stage brewing) and allowing
the saccharification of rice starch andfermentation to take place at the sametime (parallel multiple fermentation).

Yeast used for sake are characterized byhaving a high alcoholic fermentation
capacity and producing a fruity flavor likeapple or banana called “ginjoka.”
Rice koji used for sake must havesufficient amounts of diastatic enzymes
to dissolve the rice, saccharify the starchin moromi (a fermented pasty mixtureof ingredients), and produce a large
amount of glucose. This allows the yeast
to actively carry out fermentation. Koji ismade by cultivating Aspergillus oryzae onrice grains or solid culture. Liquid culture
does not allow Aspergillus oryzae toproduce sufficient amounts of enzymes.
Especially, the genes of diastatic enzymes
have been found by recent studies to be
switched on only when they are cultivatedon a solid medium. The sake production
technology developed by our ancestors
through experience can be said to bebiotechnology for skillfully manipulating
microorganisms.

Tips for exporting fermented foods shared by a long-established shoyu brewery

Since washoku, traditional Japanese food culture, was registeredas a UNESCO Intangible Cultural Heritage in 2013, it has been
attracting increasing attention, and people around the world havecome to know that it is nutritionally well-balanced and good for
health. In addition, partly owing to the dissemination of informationby those with a deep knowledge of food cultures through social
media and other channels, Japanese fermented foods have also been
gaining increasing attention. Especially, the export volume of shoyu
increased more than two-fold to 48,090 tons in 2021 from 19,822 tons
in 2012 (*). There has been steadily growing demand for shoyu fromnot only the U.S. and European countries, but also other countries.
Although many products on these markets are made by leading
manufacturers, shoyu breweries who still use traditional methods to
produce shoyu are also expanding their business overseas throughtheir own strategies.
“Unlike mass-produced shoyu products, shoyu brewed in wooden
vats is a delicate product that directly reflects the tastes and sincerityof the craftsmen brewer making it. If a brewer goes overseas anddirectly conveys the appeal of their products, that will differentiate
their products from other products,” says Mr. Kichigoro Fueki, thehead of Fueki Shoyu, a long-established brewery founded more than
230 years ago (in Saitama Prefecture). Recently, they have been
operating Shoyu Park, a park where visitors can learn about theprocess of producing shoyu, developing sweets using shoyu, andtaking on other various challenges while keeping up the tradition of
shoyu. They have so far sold their products in more than 10 overseas
countries (as of 2022). They intend to further increase their outlets.
“One of the advantages of shoyu is that it serves as a secret ingredientfor dishes while keeping the natural tastes and flavors of otherChildren learning about making shoyu at [Shoyu Park]. An actual shoyu brewery is open to
the public where visitors can observe the shoyu production process and enjoy dishes using
shoyu. In recent years, more and more foreign tourists have been visiting this facility.

ingredients. It is important for us to pursue the advantages ofindividual products and our strengths as a brewer and convey them,”
Mr. Fueki says.
Such sincere attitudes of brewers should let people around the world
know the appeals of shoyu and other Japanese fermented foods andcreate new Japanese food booms.
* The figures are based on the actual exports of agricultural, forestry and fishery products/
foods (by item) for 2021 announced by the Ministry of Agriculture Forestry and Fisheries
of Japan.
https://www.maff.go.jp/j/shokusan/export/e_info/attach/pdf/zisseki-23.pdf

14

Chapter 3 Learn about Typical Japanese Fermented Foods

3-2 Other typical fermented foods
Japanese foods are characterized by its cooking techniques, which preserve the flavors of the ingredients, and theJapanese diet based on one soup plus three dishes, healthy menus that make good use of umami, and fermented foods are
deeply related to these characteristics. All of the fermented foods introduced here are deeply related to the backgroundof Japanese food culture, and are indispensable to our daily diets.

Dried bonito
World’s hardest fermented food
responsible for creating theumami of Japanese foods
Dried bonito is a food made by smoking
a bonito fillet, drying it well, and thenspraying a mold on it to allow fermentation
to take pace. Thin shavings or powder ofthis dried bonito is used to prepare soup
stock for various dishes such as miso soup
and simmered dishes, or used as toppingsfor cold tofu, boiled greens with shoyu, etc.
The umami and fragrant flavor producedby dried bonito are indispensable forJapanese foods.
A smoked and dried bonito fillet is calledarabushi, and a fillet shaped by shaving thesurface of arabushi is called hadakabushi.
Hadakabushi is then sprayed with amold to make karebushi, which is further
sprayed with a mold several times to makehonkarebushi.

The history of dried bonito
In Japan, bonito has been eaten sinceancient times, and descriptions of driedbonito-like foods such as katsuo (hard fish)
can be found in Kojiki (Records of Ancient
Matters) written in the 8th century, theoldest existing history book of Japan. In
the Engishiki written in the middle of the
Heian era (around the 10th century), boiled
and dried bonito appear as nikatauo (a fish
boiled and dried hard). Nikatauo was driedby the sun in this era. In the Muromachi
era, bonito came to be smoked and driedby using fire and smoke, and calledkatsuobushi, the present Japanese namefor dried bonito. Shijoryu Hochogaki, a
cookbook in the Muromachi era, uses theword Hanakatsuo (dried bonito shavings),
and shows that hanakatsuo was used
together with shoyu to flavor dishes.
It is said that spraying a mold after theprocess of roast-drying *1 was started in
Tosa Province (Kochi Prefecture) in the
mid-1600s. Dried bonito made in Tosa wascalled Tosabushi and was sprayed withmold only once. Subsequently, the processof spraying a mold came to be repeated toreduce the fishy smell, increase umami,

and produce the unique flavor, resulting in
the current honkarebushi.

Production method
Dried bonito is produced as follows.
First, cut off the head of a bonito, remove
the internal organs, and then fillet it into
three parts. If they are large in size, cutthem into the dorsal part and abdominal
part. Put the bonito fillets in a basket,
place it in a cooking pot, stew*2 them ataround 80oC for 60 to 90 minutes, allow
them to cool, and then manually remove
the bones. The fillets roast-dried once
after these steps are called namaribushi.
Repeat roast-drying about 10 times to
produce completely black masses covered
with a tarry substance. Shave off the tarry
substance on the surface of this arabushi
to turn it into hadakabushi, and spray itwith a beneficial mold*3. Then, the surface
will be covered with the mold in 1 to 2
weeks. Beneficial molds are characterizedby having strong lipolytic ability, and weakproteolytic ability. Sun dry the masses withthe mold on the surface, brush the moldoff the surface, and spray the mold again.
By repeating this last process of drying,brushing, and spraying the mold 4 times,
honkarebushi can be obtained. It takes
60 to 80 days to make dried bonito from awhole bonito fish.
The greatest characteristic of dried bonito
is its hardness. This hardness is because
its water content has been reduced toapprox. 15% by repeatedly roast-drying
and spraying it with mold. Drying to theutmost limit creates an environment where
microorganisms cannot grow, increasing
its shelf life. In addition, the sprayedmold decomposes and removes fat, which
prevents soup stock extracted from driedbonito from clouding, as seen in soup stock
extracted from chicken or pork bone.
Dried bonito contains a rich amount of
5'-inosinic acid, an umami component. It is
known that the combination of 5'-inosinicacid and glutamic acid, which is anotherumami component, creates a synergetic
effect and enhances umami. Mixed soup
stock extracted from both dried bonito andkombu seaweed is exactly the product ofthat synergetic effect. The value of driedbonito also lies in its flavor produced by

15

the processes of roast-drying and moldspraying. More than 400 kinds of flavor
components, including alcohols, phenols,
and carbonyl compounds, created throughthis process have been found.
Previously, special cutter boxes for driedbonito were used in general households,
but today, dried bonito is sold in the formof shavings. However, the flavor unique todried bonito is irreplaceable, and it is stilltrue that dried bonito is indispensable forJapanese foods and Japanese people.

Other bushi types
Dried bonito has different names
depending on the production area. For
example, it is called “Tosa bushi” or“Satsuma bushi” in Kagoshima Prefecture,or “Izu bushi” or “Yaizu bushi” in Shizuoka
Prefecture. They have different shapes,
flavors, and other characteristics unique tothe regions. Today, Kagoshima Prefectureand Shizuoka Prefecture are the two major
production areas of dried bonito. Dried
fishes other than bonito are also producedin various regions. These include driedsoda or bullet tuna (bullet mackerel, frigate
mackerel or sumasoda), dried tuna, driedmackerel, dried mackerel scad (mackerel
scad or jack mackerel), dried round
herring, and dried sardines (anchovies).
With different color shades and flavors,
these dried fishes are used to make soup
stock for soup called “osuimono,” miso
soup, soba noodles, udon noodles, Chinese
noodles, and other various dishes. Thus,
they are supporting the tastes of Japanesefood in various ways.
*1 Process of drying while smoking used for dried bonito.
This process has the effects of concentrating umami,
preventing rot, and killing fishy smells.
*2 Process of stewing raw bonitos after they are cut andtrimmed. While they are stewed, water is poured so
as not to stew in boiling water. This process has theeffects of preventing the bonito from rotting, making
them easier to dry, and locking in the umami.
*3 Eurotium species (Eurotium herbariorum andEurotium repens) and Aspergillus glaucus, a moldrelated to Aspergillus oryzae, are used.

Chapter 3 Learn about Typical Japanese Fermented Foods

Natto
Well-balanced nutritional foodwith a unique, addictive smell andflavorJapanese natto is first associated withitohiki (stringy) natto put on top of rice.
Natto is a salt-free soybean productmade by fermenting boiled soybeans with
Bacillus subtilis natto, and is characterized
by its unique smell and viscous substanceproduced by fermentation. It is extremely
nutritious, and is today eaten together
with rice across the country on a daily
basis. Previously, however, it was eaten asa valuable source of protein in the frigid
Tohoku region.
In Japan, there is another kind of natto
called “shiokara (salted and fermented)
natto” (or hama natto or tera natto).
It is made by using soybean koji from
inoculating Aspergillus oryzae rather thanBacillus subtilis natto in boiled soybeans.

Mirin
Sake that evolved from a beverage
into a seasoning
Mirin is a liquid, sweet fermented
seasoning containing approx. 45%
sugar and approx. 14% alcohol. It
is also considered as one of Japan’snational drinks like sake, and is often
used in cooking together with shoyu
as an alcohol-based seasoning that is
indispensable for giving a sweet taste toJapanese foods.
When used in cooking, mirin has various
beneficial effects. For example, it can beused to give a sweet taste or a glossy or
shiny look to dishes, gives a soft but sharp
sweetness to dishes, help liquid seasoning
components to soak into foodstuffs,
prevents foodstuffs from softening andfalling apart during boiling, and remove
fishy smells. These effects are mainly due
to alcohol and sugars contained in mirin.
It is believed that mirin originated in asweet alcoholic beverage called nerizake in
the Muromachi era (14th to 16th century),or another sweet alcohol beverage calledmiirin and introduced from China in the
Sengoku period (15th to 17th century).
Komai Nikki, a diary of a man named
Komai written in 1593, is the first bookwhere the name mirin appears. Mirin was
drunk as a sweet alcoholic beverage at

Soybean koji is immersed in salt waterto allow it to carry out lactic acidfermentation, and then dried into shiokara
natto. It is believed that shiokara natto
was modeled after kuki, which is Chinese
salt-cured fermented soybeans and isconsidered as the origin of Japanese miso.
It has a longer history than itohiki natto,
and is believed to have already been madeback in the Nara era.
It is unknown when people started
making itohiki natto. Although there
are various stories regarding its origin,
all stories commonly indicate that it
originated in the Asuka era (6th to 7th
century) or the Heian era (9th to 11th
century), and boiled soybeans wrapped instraw were unexpectedly found to emit
an odor and have changed into a viscous,
stringy state. In Shojin Gyorui Monogatari,a tale of vegetables and fishes written in
the Muromachi era (14th century), NattoTaro Itoshige, a character apparently
considered to personify itohiki natto,
appears, which suggests that itohiki natto
was already present at least at that time.

Until before the Edo era, natto was madeat homes and eaten as an ingredient insoup dishes. In the Edo era, industrial
production of natto began, and itohiki
natto started to be put on top of rice ataround this time. Itohiki natto contains
rich amounts of vitamins such as vitamins
B1 and B2, minerals, and calcium, is easy
to digest and absorb, and thus, was a foodsuitable for Japanese people at that time,
who lived on plain food.
There are salt-free fermented soybean
foods similar to Japanese natto in other
Asian countries, such as tempeh eaten inIndonesia and kinema introduced in Nepal
and Bhutan, but it is only Japanese natto
that is put on top of rice.

that time, but since very sweet mirin madeby brewing glutinous rice and rice koji inshochu like today’s mirin appeared in thelate Edo era, it came to be used as a sweet
seasoning. Many cookbooks published in
the late Edo era carry recipes for various
dishes using mirin, suggesting thatmirin had become established as a basic
seasoning at that time.
Mirin is made by adding shochu or an
alcohol for brewing to steamed glutinous
rice and rice koji and allowing theingredients to ferment for 40 to 60 days.
For this reason, production of mirin
does not involve the process of alcoholic
fermentation. The enzymes in Aspergillus
oryzae are allowed to act in the presenceof alcohol, which serves as a preservative,
and as a result, sugar is produced by thesaccharification of starch, and amino acids
are produced by protein degradation.
The reason that glutinous rice is used isthat glutinous rice starch is less prone toretrogradation compared to non-glutinous
rice starch, and is more susceptible tothe action of the enzymes in Aspergillus
oryzae. Moromi after fermentation ispressed into products, and the residue
after the pressing is used as mirin lees formaking pickles or in pickling media formaking pickled fish or meat.
Glucose constitutes 80% to 90% of thesweetness components of mirin, but it
contains other various sugars such as
isomaltose, kojibiose, maltose, andα-ethylglucoside. This gives mirin its
complex, elegant sweetness.
Mirin is also called hon (true) mirin.
There are seasonings similar to mirinsuch as seasonings that mimic mirin andfermented seasonings (cooking sake).
Seasonings that mimic mirin do notcontain alcohol and are made by blending
additional sugars. Fermented seasonings
are made by adding salt to a salt level ofapprox. 2% after alcoholic fermentation
for making the products undrinkable.
Hon (literally, “true”) mirin falls under
the category of alcoholic beverages,
but is not suitable for drinking. It is
used as a seasoning. There is anothersweet alcoholic beverage that falls
under alcoholic beverages but is usedin cooking like hon mirin. It is called“akumochizake” and is brewed with asmall amount of water and matured withwood ash added. As a result, a dark brown,
sweet alcoholic beverage is produced.
Akazake of Kumamoto Prefecture, Jizake
of Kagoshima Prefecture, and Jidenshu
of Shimane Prefecture are well-known
akumochizake.

16

Chapter 3 Learn about Typical Japanese Fermented Foods

VinegarDriving force behind today’s sushi
Vinegar is a liquid seasoning made fromrice, barley, fruits, or other ingredientsby fermentation with acetic acid bacteria.
The origin of the word vinegar is vinaigre(vin+aigre) in French, which means sourwine. As suggested by the word origin,vinegar was made as a result of ethanol
contained in an alcohol beverage beingchanged into acetic acid by acetic acidbacteria and turning sour, and thus has aclose relationship to alcohol.
In the around 4th century, vinegar
production technology was introduced
from China to Japan together with thesake production technology. Rice vinegar
first became popular in Japan, and themethod of mixing rice koji, steamed
rice, and water in a vat and allowing the
mixture to ferment in a static state (static
fermentation) was used until the Edo era(the late 19th century).
In the Heian era, a small dish containing
vinegar was placed as a seasoning on
nobles’ dining tables together withsalt and sake, and they ate disheswith these seasonings. It is believedthat because there were no effectivemeans of preserving foodstuffs at thattime, foodstuffs had to be disinfectedwith seasonings. In the Kamakura andMuromachi eras, vinegared dishes suchas namasu (thin strips of raw meat or fish
dressed with vinegar) became popular.
In history books describing the Edo era,
there appear many descriptions of vinegar
mixes made of vinegar and spices or miso.
It is the Heian era when a vinegar
production method appeared for the firsttime in a Japanese book, and vinegar
described in books published since thenthroughout the Edo era is mostly rice
vinegar. When it comes to other kinds ofvinegar, only several descriptions of sakevinegar (vinegar that was produced assake but turned sour) can be found. Thissuggests that rice vinegar was developedin Japan since ancient times.

Pickles
Fruit of the wisdom from taking
advantage of regional climates
Japanese pickles are divided into
unfermented pickles and fermented
pickles. Asazuke (lightly soaked pickles)
and chomizuke (seasoned pickles) aremade by soaking foodstuffs in salt, shoyu,

Production methods for vinegar
In Japan, production methods for vinegar
are roughly divided into two types: oneis the traditional surface fermentation(static fermentation) method, andanother is the deep fermentation method(fermentation by stirring for aeration)used for the industrial productionof vinegar products. The pot vinegar
production method handed down in someregions, including Fukuyama, a town
in Kagoshima Prefecture, is typical of
the former method. This is the methodof putting rice koji, steamed rice, andwater in pots and leaving them outside
for 6 months. In the pots, lactic acidfermentation and saccharification occur,and then when alcoholic fermentation
starts, acetic acid bacteria soon form athin film on the liquid surface and carries
out acetic acid fermentation. This meansthat the enzymes in Aspergillus oryzae
work as well as lactic acid bacteria,
yeast, and acetic acid bacteria carry out
fermentation sequentially in the pots,
and then vinegar is produced throughthese processes. Acetic acid fermentationends in six months, but the content in
the pots is allowed to further mature forsix months to three years. During thisperiod, the liquid turns a dark goldenbrown. For this reason, vinegar producedby this method is called “kurozu (meaning“black vinegar”).” Kurozu is made by using
unpolished rice or rice that is not completely
polished, and using 4.5 times more rice than
general rice vinegar. As a result, kurozu isespecially rich in amino acids.
On the other hand, the deep fermentationbased rice vinegar production method
involves two fermentation steps. Sake ismade from rice first, and then an acetic
acid bacterial film is inoculated into thesake to allow static acetic acid fermentation
to take place. Grain vinegar made using
sake lees obtained as a by-product of sakeproduction is called kasuzu (lees vinegar).
By maturing sake lees for a certain periodof time, adding water, then inoculating an
acetic acid bacterial film into the mixture
to allow static fermentation to take place,kasuzu can be produced. As the sugar andamino acid content in sake lees increaseduring maturation, sake lees look red,which reflects the progression of theMaillard reaction (*) during fermentationand maturation. Dark red kasu vinegar iscalled “red vinegar”.

Uses for vinegar
Among the various kinds of vinegar, it wasrice vinegar that had been mainly developed
until the Edo era in Japan. Since the Meiji
era, various kinds of vinegar, including
fruit vinegar, has become popular with theadvancement of vinegar manufacturing
technologies. Rice vinegar mixed with miso,
soy sauce, soup stock, spices, etc. has beenused in Japanese dishes. Rice vinegar is used
to make vinegared rice, and kasu vinegar
is especially said to go well with Edo-style
nigirizushi (small rice balls with a slice ofraw fish on them). Kasuzu, which is lessexpensive than rice vinegar, contributed tothe spread of today’s sushi and has grown indemand with the development of sushi.
Vinegar gives dishes a sour taste as well as
removes unpleasant odors from foodstuffs,
makes the colors of foodstuffs look bright, hasa strong disinfectant capability, making andfoodstuffs last longer. Thus, it has various
beneficial effects when used in cooking
and helps to preserve foodstuffs longer.
In addition, recent studies have identified
various functionalities of vinegar, and it has
an increasingly wide variety of uses.

Pot vinegar production being conducted through traditionalsurface fermentation (Kirishima City, Kagoshima Prefecture)© K.P.V.B* A reaction that takes place between sugar and amino acids,
etc. when heated and produces melanoidin, a brown substanceor other seasoning liquids for a short time
to saturate them with the seasoning’s
taste, and are unfermented pickles. On
the other hand, it is said that the root of
fermented pickles is kusabishio, a kindof Chinese hishio made by salting andfermenting foodstuffs. Vegetables weresalted to improve their shelf life andfermentation gave them a better flavor.
Then, these vegetables came to be eaten
as fermented pickles. This technique soon
spread across Japan, and local fermented
foods made by using local vegetables havesince developed.
In the process of making fermented
pickles by salting,etc., lactic acid bacteria,

17Chapter 3 Learn about Typical Japanese Fermented Foods

etc. adhering to vegetables can growduring salting, which increases the flavor
unique to fermentation. First, as lactic
acid bacteria grow, a decrease in the pH
due to lactic acid makes it difficult forundesirable bacteria to grow. At the sametime, the lactic acid bacteria come to lose
their growth power, and acid-resistantlactic acid bacteria (of a kind different fromthe previous lactic acid bacteria) instead
start to grow. As fermentation proceeds,
the cells of the ingredient vegetables arebroken down to allow them to have a softer
texture, and the fermentation components

AmazakeFermented
drink
calleddrinkable intravenous dripaAmazake is a very sweet drink made byadding water to rice koji or to rice koji andrice and heating the mixture to cause it toundergo saccharification. “Zake” in amazakemeans sake, but it is alcohol-free and does
not fall under the category of alcoholic
beverages.
Nihonshoki (Chronicles of Japan), a
history book written in the Nara era,
contains a description of amanotamuzake,
which is closer to amazake rather than
today’s sake, and is considered to havebeen very sweet sake made of rice koji but
contained a very small concentration of
alcohol. It is said that amazake came to be
drunk by ordinary people in the Edo era,and especially in summer, many amazake
peddlers were seen on the streets because
people at that time tried to survive the hotsummers by drinking amazake due to its
high nutritious value, so much so that itwas called a drinkable intravenous drip.

Columnsoak into them to increase sourness or
umami, producing a refreshing flavor
unique to fermentation.
Nukazuke (rice bran pickles) is anotherkind of pickles made by using rice bran
(powder generated in the process ofpolishing brown rice into white rice). Ina rice bran bed, which is generally used
repeatedly for long periods of time tocreate generations of lactic acid bacteria,
yeast, and other various bacteria andproduce the complex microbial flora innukazuke. For this reason, nukazuke has acomplex and unique flavor.
Amazake is made by mixing rice koji formaking miso and water, or equal amountsof rice koji, cooked rice, and water, andheating the mixture at 55 to 60°C
overnight. Cooked glutinous rice is often
used. If rice koji is available, amazake canbe made easily at home. However, with thebooming of koji in Japan, many brewers
have recently come to sell amazake.
In the process of producing amazake, anAspergillus oryzae-derived amylase actson starch, which is the main component ofrice, to produce a large amount of glucose,which is the main component of amazake.
In addition, rice protein is degraded byan Aspergillus oryzae-derived protease to
produce peptides and amino acids.
Amazake also contains B vitamins asmetabolites of Aspergillus oryzae anddietary fiber that composes Aspergillus
oryzae cells and rice. Since amazake
contains a large amount of glucose andvitamins and minerals necessary for sugar
metabolism, it can be said to be a drinkthat quickly helps us recover from fatigue.
In addition, rice-derived glucosylceramide
and N-acetylglucosamine in Aspergillus
oryzae, which promote the synthesis of

Pickles have developed as the fruitof the wisdom for preserving valuable
foodstuffs longer, and it is said that
there are more than 600 kinds of pickles
produced in various regions in Japan. In
Japan, there are a variety of marinades andpickling beds and a variety of ingredientsthat can be pickled as well as a variety
of appropriate pickling methods forsuch marinades and pickling beds. By
combining these elements, Japan became
one of the world’s largest producers of
pickles.

collagen and hyaluronic acid involved
in helping our skin retain water, can be
expected to provide beauty effects.
Amazake may also be made by using sakelees rather than rice koji, and amazake
made of rice koji is called koji amazake,and amazake made of sake lees sakekasu
amazake. Sakekasu amazake is made bydissolving sake lees in hot water andadding sugar, and may contain traces ofsome alcohol left in sake lees. The
production of sakekasu amazake does not
involve a fermentation process, butsakekasu amazake can also be said to be afermented drink as sake lees is aby-product of brewing sake.

Power of fermented seasonings to bring umami out of foodstuffs

Many basic seasonings used in Japan are fermented seasonings, andkoji is indispensable for producing these seasonings. The main roleof koji is to decompose foodstuff components. For example, in theprocess of producing amazake, the amylolytic enzymes produced
by Aspergillus oryzae decompose rice starch into glucose, giving
amazake its rich, sweet taste. In the process of producing shoyu,
the proteolytic enzymes produced by Aspergillus oryzae decompose
soybean protein and wheat protein into amino acids, which give richumami to shoyu. Generally, protein and starch have no taste. They
are decomposed by enzymes into amino acids or glucose, which
produces umami or sweetness.
However, taste is complex. The 20 amino acids can be arranged andbonded in a certain sequence to make straight chains, which is folded
into a giant protein molecule. The bonds holding the chain together

are called peptide bonds, and a series of several amino acids
connected by peptide bonds is a peptide. Peptides are always
contained in fermented foods. Proteolytic enzymes from Aspergillus
oryzae can break this peptide bond and fragment proteins. These
20 amino acids include not only glutamic acid, which produces
umami, but also glycine and alanine, which produce sweetness, andvaline and leucine, which produce bitterness. Thus, amino acids
have a variety of tastes, and when they connect to make a chain
through peptide bonds, a completely different taste is produced.
Different peptides of amino acids arranged in different sequences
produce different complex and thick tastes or robust tastes. The richand complex tastes of fermented foods come from peptides, andAspergillus oryzae, which produces these peptides, is the source offermented foods.

18Chapter 4 Learn about the Science of Fermentation Foods

Bringing Japanese fermentation
technologies to the world
Kenji Maehashi

Professor at the Department of Fermentation Science, Faculty ofApplied Bio-Science, Tokyo University of Agriculture

The author, born in 1969, accomplished credits for a doctoral program (second term) at the Division of Agriculture, Tokyo
University of Agriculture Graduate School, and received a PhD in agricultural chemistry. He is engaged in the study of factorsthat enrich eating habits such as seasonings, tastiness, and tastes. He continuously takes a scientific approach to fermentationand tastes, and more specifically, foodstuff changes caused by fermentation, fermented seasonings, analysis of tastes, andthe mechanism of the sense of taste. His works include the following three publications written in Japanese: “Koji’s MagicalPower to Create Umami/旨みを醸し出す麹のふしぎな料理力,” (co-authored, Tokyo University of Agriculture Shuppankai),“Proposal to Use Koji Amazake instead of Sugar/砂糖の代わりに糀甘酒を使うという提案,” (co-authored, Ascom Inc.) and"Immunity-Conscious Life with only Cloudy Vinegar/にごり酢だけの免疫生活", (Seishun Shuppansya).

How is “oishisa(tastiness)” produced?
I study specifically fermented foods inthe field of fermentation science, andplace the most emphasis on their tastes
or oishisa. Naturally, foods must be tasty.
Appreciating oishisa or joy brought byoishisa makes everyone on earth happy.
In line with this idea, I focus especiallyon seasonings, and more specifically, on
fermented seasonings that take advantage
of fermentation to make foods tasty. By
approaching oishisa from the mechanism
by which humans sense tastes andcomponent changes that occur in foods,
we are coming to understand how oishisa
is produced.
For example, some studies revealed thatlysozyme, a protein in egg whites, tastes
sweet. Lysozyme is an immunoprotein
contained in egg whites as well as inmammals’ breast milk. It is also containedin cold medicines. How is the sweetness
produced? It tastes sweet because thetongue sensor for sweetness is activated by
the positive and negative charges on thesurface of the lysozyme molecule. In otherwords, molecular structures are importantfor humans to feel the tastes of substances.
Only molecules with certain structures
present a taste. Interactions between
molecules may prevent bitterness frombeing felt or bring out sweetness or umami.
Foods are savored through a fairly complex
mechanism, and an infinite number oftastes sensed through that mechanism canbe produced. It may be possible to produce
tastes beyond our imagination.
One taste component that has seen
active research for a long time is
peptides produced as a result of protein
degradation. Peptides are not a main
player in producing tastes, but havethe role of producing a good taste. Of
the 20 kinds of amino acids, different
ones connect to make different peptide
structures. Consequently, there are an
infinite number of peptide structures withdifferent types, numbers, and sequencesof amino acids. Peptides with a certain

structure have been found to have anantioxidation effect, a hypotensive
effect, or other functionalities. A slightdifference in structure results in different
physiological activity as well as different
taste. These peptides are involved in thetastes of fermented foods containing
lots of protein degradation products, andcombinations of an infinite number of
peptides varying in taste produce tasty
fermented foods with specific complex
umami.
The same goes for components other thanprotein, such as starch. A microorganism’s
enzymes decompose components andseparate a single molecule into an infinite
number of smaller molecules, which
produces not only a wider variety of tastes
but also solid and thick umami. This is thewonder of fermentation. We have not yet
found all of the specific molecules involvedin fermentation, and elucidating theseone by one is my goal, and is essential formaking the depth of Japanese fermented
foods known to the world.

“Koji” is the basis forfermentation in Japan
In 2013, washoku, traditional Japanese foodculture, was registered as an Intangible
Cultural Heritage by the UNESCO. Since
then, Japanese fermentation culture andfermented foods have been attracting
greater attention. One of these is shio-koji(*), which is easy to incorporate in thedaily diet, and it has come into general19

use as a popular seasoning. It is common
knowledge in the field of zymology thatenzyme-rich koji produces umami, but
this opportunity seems to have given koji,
which had previously been playing thebehind-the-scene role in producing shoyu
and miso, a good chance to come into the
spotlight. “Temae-miso” is a Japanese
idiom for self-praise. The term literallymeans “my own miso.” As suggested bythis word, miso had been made in every
home since the Edo era. Japanese people offormer days pickled vegetables in koji left
over after the miso-making process. Thismeans that the technology of shio-koji has
existed since a very long time ago. Leftoverkoji is not discarded but reused with care.
The wisdom of the Japanese can be seen inthis practice.
Actually, shio-koji itself does not containmany umami components, but the resultsof analyses on its components revealed
that its principal component is sweet, aswith amazake. The salt in it prevents itfrom tasting sweet, but when it is used in
cooking, appropriate saltiness is combinedwith sweetness to produce a good taste
or umami. The enzymes in koji act onfoodstuffs, producing umami and making
them tasty. The power of koji brings out
the tastes of foodstuffs. This can be said
to be the greatest feature of Japanese
fermented seasonings. From analyzing
the effects of shio-koji, we were able torediscover the fact that koji is the basis forJapanese fermented foods.

Chapter 4 Learn about the Science of Fermentation Foods

Japan has developed its own fermentation
technologies that compare favorably withthose outside Japan. The main feature isthat various fermented foods are made bymainly using koji, and these fermented
foods are used as seasonings. By using
fermented seasonings made using koji, we
can receive the benefits of fermentationfrom our daily diet. Koji is a pillar of theJapanese diet.

Shio-koji is a salty fermented seasoning made bymixing approximately 10% salt, rice koji, and water toeffect saccharification. It is generally a gruel-like or
pasty seasoning, but may be in a powder or liquid state,
which is not common. Rice koji is steamed rice in which
Aspergillus oryzae has been cultivated, and contains
various digestive enzymes produced by the mold whenit grows. Especially, rice koji contains rich amountsof amylolytic enzymes, and adding water to rice koji
and heating the mixture produce highly concentrated
glucose since the rice starch is digested in the process.
Shio-koji contains koji enzymes even after it is put on
the market, and the enzymes bring about changes tofoodstuffs when it is used in cooking.

Invisible fermentation andvisible fermentation
Japanese people have used its own
food technologies to bring out umami
and sweetness even from less flavorful
foodstuffs, and harmonize seasonings
with foodstuffs in a fine balance. We havebeen continuously producing Japanese
foods with delicate tastes by combining
different kinds of kitchen knife skills
with different cooking methods such as
boiling, steaming, stewing, and grillingand using enzymes in foodstuffs to bringout flavors from them. We combine
cooking technologies that take advantageof the tastes of foods with enzymes in koji
to bring out complex umami specific toJapanese foods. In the West, on the other
hand, scientific and functional cooking
methods are popular. Western people
generally extract good components
from foodstuffs, and add single taste
substances such as salt and sugar to add
flavors.
Japanese traditional fermentation
processes use microorganisms in a very
complex and delicate manner. The
technology for manipulating invisible

microorganisms is almost mysterious.
This is considered to be based on our foodculture of cereals, vegetables, and fisheryproducts, and on the ancient Chinese ideaof Hishio (salted food) or the technologyof pickling these foodstuffs with a large
amount of salt and preserving them in a
hot and humid environment. The idea isthat pickling foodstuffs with salt allows
only useful microorganisms to cause
natural fermentation without rottingthem.
On the other hand, fermentation in
the West is more simple and morerational. For example, the fermentation
process must be clear as seen in theprocess of making yogurt by adding lactic
acid bacteria to milk, or the process ofmaking wine by adding yeast to grape
juice. Western people may feel anxious
about the hygienic safety of keeping
foods at ordinary temperatures to growunidentified microorganisms.
Since ancient times, Japan, without
knowing the existence of microorganisms,
has cultivated fermentation technologies
through experience and trial and error. In
modern days, the power of science allows
us to unlock the secrets of fermentation
to some extent. For example, in theprocess of making koji, how to steam rice,
how to mix and warm koji, and all othermethods for handling koji are scientificallysignificant. Sophisticated fermentation
technologies produce fermented foods
that are of high quality and offer excellent
health benefits. Elucidating this complex
mechanism is an interesting challenge
for me as a researcher, and I am sure thattaking on this challenge will help to spreadsafer fermentation techniques acrossthe world. Eventually, the mechanism
will be elucidated at the molecular level,
which will help to reveal what effects
fermentation has on the human bodyand find more specific means for using
fermentation for our health.

and what lifestyle is led there. Our taste
and flavor preferences are developed
after birth, and we come to know ourown likes and dislikes about foods inthe course of living. What tastes people
like is quite different depending on theregion they were born in and their race.
We combine foods eaten in a region withmicroorganisms to produce fermented
foods unique to that region. Koji is atechnology that helps this process.
By turning a foodstuff into koji by afermentation technology using Aspergillus
oryzae, whatever the foodstuff is, afermented product with a unique flavor
can be made. This fermented productor koji can be combined with anothermicroorganism to promote further
fermentation.
Recently, there have been an increasing
number of studies on Japanese fermented
foods outside Japan, but it seems that what
has already been known in Japan sincequite a long time ago is being reported bymany of these studies. This may be because
information in this field has been shared in
the country but has not been disseminatedadequately to the world.
However, the concept that “Japanese
fermentation is invisible” is about to reacha turning point. This is because significant
advances in technologies for analyzing
genes and components are enabling us toscientifically elucidate the phenomenonof fermentation, the characteristics of
microorganisms, etc. For example, moldis intrinsically poisonous, but the analysis
results demonstrated that Aspergillus
oryzae, a mold that has been domesticatedby the Japanese over a long period of time,
is not poisonous but safe. If evidence canbe obtained, what effects fermentation has
can be explained from medical, sitological,
and bromatological perspectives, andthe idea that food is medicine could bedemonstrated by the health benefits of

Spreading Koji technologies
across the world
To spread the wonder of Japanese
fermentation across the world, it isnecessary not only to raise awarenessto existing fermented foods, but also
to spread and let people around theworld know Japanese-style fermentation
technologies. To do this, we first needto understand regional cultures, suchas what foods are eaten by a particularethnic group in that country or region,

20

A giant colony of Asperugillus oryzae cultured in apetri dish.
Research has played a role in promoting visualizationof the Japanese fermentation technology.

Chapter 4 Learn about the Science of Fermentation Foods

traditional fermented foods.

The future created throughcoexistence with microorganisms
I think that fermentation technologies
could be used to address a food crisis we
may encounter in the future, or protein
insufficiency. Amino acids, which arematerials for protein, can be mass-produced
using microorganisms. A typical mass-

Columnproduction method of this kind is glutamic
acid fermentation, a technology invented
by the Japanese and is currently usedaround the world. Some microorganisms
can mass-produce protein. There is a goodchance that microorganisms with newcapabilities may be found in the futuresince there are an infinite number ofmicroorganisms on Earth still unknown
to human beings, and even traditional
fermented foods may contain some

unknown microorganisms. By making
effective use of the fermenting power ofmicroorganisms, it may be possible to finda clue to solving food crises in the future.
Microorganisms have existed long before
the birth of human beings. The idea thatthe true coexistence of microorganisms
and human beings may significantly
change the future once again makes me
excited about how great the secrets offermentation are.

Learn from wisdom given by fermented foods

There are countless fermented foods in various regions around Japan. Unique foods have been produced by taking advantage ofthe climates of various regions, the variety of local foodstuffs, and the wisdom of people living there that has been handed down
to date.Of the unique fermented foods not covered in this booklet, the editorial supervisor introduces three of them here:

Daitokuji (Daitoku-ji Temple) natto / Kyoto Prefecture
Hishio that retains the original form of miso and shoyu
This is natto introduced to the Daitoku-ji Temple in Kyoto Prefecture, which provides theorigin of its name. It is also called “shiokara natto” or “tera natto.” This natto is not stringy
like itohiki natto, and is made by allowing Aspergillus oryzae rather than Bacillus subtilis
natto to ferment the soybeans. This natto contains a high concentration of salt because
soybeans are pickled with a high concentration of salt. As fermentation by halotolerant
lactic acid bacteria also takes place in this process, it has a strong salty, umami, and sour
taste. This natto is quite similar to Chinese touchi, is like the original form of miso, and ismade by methods similar to those for making soybean miso or tamari shoyu. It is eaten as asnack served with tea as it is or used as a seasoning in cooking.

Kabura zushi (turnip sushi) / Ishikawa Prefecture, Toyama Prefecture
Pickled fish, a lacto-fermented food that is rarein the world
This is a traditional fermented food made in Ishikawa Prefecture and Toyama Prefecture. It
is made by sandwiching a slice of a yellowtail between turnip slices and allowing the sandwich
to ferment. It is called sushi, but does not use vinegared rice and is a kind of sliced pickles
rather than sushi. It is like sushi where the turnip slices substitute for rice. Since salted
yellowtail slices are pickled together with turnip slices and rice koji, lactic acid fermentation
takes place, which gives the dish a sour taste. In this sense, Kabura zushi can be said to be akind of fermented sushi called “nare-zushi.” It does not have a distinct flavor like traditional
nare-zushi, as it is easy to eat and not aggressively flavored.

Miki / Kagoshima Prefecture
Drink with a wild flavor made by lactic acid fermentation
This is a traditional fermented drink popular in the Amami Islands. It is made by using
different ingredients, such as rice powder, sweet potato, rice koji, and barley koji, dependingon the island. Miki made from barley koji and rice powder has a subtly sour taste like freshamazake. Miki is made by adding water to ingredients, kneading the mixture, and leaving it tosit at room temperature to allow lactic acid bacteria to carry out fermentation. This produces
a sour taste unique to lactic acid21

Conclusion

Let’s incorporate fermented foods into our daily diets.

The more you know about fermented foods, the more you Books written about Hippocrates carry a recipe for making oxymel,
recognize their depth, but there is no point if you do not savor saying that oxymel could be made by boiling honey, adding thethem in your daily diet. They can also be expected to offer health same quantity of vinegar, and diluting the mixture to 20 times as
benefits, and it would be a waste not to eat them. In the end, let us much water.
introduce a fermented food that can be made easily and consumed

In modern days, studies have been made on which components

on a daily basis.

of vinegar are beneficial to health, and it has been reported that

A drink called oxymel can be made by mixing vinegar and honey, acetic acid, which is the main component of vinegar, has a bloodthen diluting the mixture with water. It is a drink with a slightly pressure lowering effect, a visceral fat reduction effect, andsour and subtly sweet taste and can be drunk easily on a daily basis other functionalities. And recently it is suggested that acetic acidto obtain the health benefits of vinegar. During the summer, you bacteria used in vinegar production has the effect of regulating
may want to dilute it with carbonated water. It is said that oxymel the immune system due to a component in its cell wall.
is a drink recommended by Hippocrates, the father of medicine(around 400 B.C.).

Fermented foods are the product of the accumulated wisdom
and experience of our ancestors, which have been handed down

In ancient Greece, vinegar was widely used for medicinal to modern day. We have been enjoying the wonderful world of
purposes, and it is believed that Hippocrates prescribed vinegar as fermented foods and have been entrusted with the mission totreatment for most diseases including common colds and coughs. pass it on to future generations.

Information about related websites

Our Regional Cuisines
A website that introduces regional cuisines that use fermented foods introduced in this booklet, and provides
information about various regions in which the culture of eating fermented foods has taken root was created. The
website can be viewed in five languages (English, simplified Chinese, traditional Chinese, Spanish, and Thai).
Please visit these websites.

・All contents of this booklet are copyrighted by the Ministry of Agriculture, Forestry and Fisheries, or used by the Ministry ofAgriculture, Forestry and Fisheries with the permission of the copyright holder.
・If copying, duplicating, reprinting, putting to another use, editing, modifying, transmitting, broadcasting, distributing, lending,translating or altering part or all of this booklet, please use those contents upon specifying the reference source (Ministry ofAgriculture, Forestry and Fisheries’ “Traditional Foods in Japan”).
・Selling this booklet or a processed or edited version of this booklet is prohibited.

An Introduction to Japanese fermented foods
Issued March 7, 2023
Published by

Ministry of Agriculture, Forestry and Fisheries, Minister’s Secretariat, New Business and Food Industry
Department, Food Service Industry and Food Cultures Division, Food Cultures Office
1-2-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8950
TEL: 03-3502-8111 (main line)

Supervising editor

Kenji Maehashi

Editing/production[Gurunavi Washoku Culture and Traditional Food Review Committee] OfficeThis booklet is freely available for public use.
This booklet was created in 2022 as a “Commissioned project to organize and communicate information about the diverse values ofJapan’s food culture, as part of the support project within export promotion collaboration targeting visitors from foreign countries.”