Miso

Miso(みそor味噌)is a traditionalJapanese seasoning. It is a thick paste produced byfermentingsoybeanswith salt andkōji(the fungusAspergillus oryzae), and sometimes rice, barley,seaweed, or other ingredients. It is used for sauces and spreads; pickling vegetables, fish, or meats; and mixing withdashisoup stockto serve asmiso soup, a Japanese culinary staple food. Miso is high in protein and rich in vitamins and minerals, and it played an important nutritional role infeudal Japan. Miso is widely used in both traditional and modern cooking in Japan, and as of 2018 had been gaining worldwide interest.
Typically, miso is salty, but its flavor and aroma depend on the ingredients and fermentation process. Different varieties of miso have been variously described as salty, sweet, earthy, fruity, orsavory.
The origin of miso of Japan is not completely clear.
In theKamakura period(1185–1333), a common meal was made up of a bowl of rice, some dried fish, a serving of miso, and a fresh vegetable. Until theMuromachi period(1337 to 1573), miso was made without grinding the soybeans, somewhat likenattō. In the Muromachi era,Buddhist monksdiscovered that soybeans could be ground into a paste, spawning new methods using miso to flavor other foods. In medieval times, the wordtemaemiso, meaning homemade miso, appeared. Miso production is relatively simple, so homemade versions spread throughout Japan. Miso was used as military provisions during theSengoku period, and making miso was an important economic activity fordaimyōsof that era.
During theEdo period(1603–1868), miso was also calledhishio(醤) andkuki(豆支)and various types of miso that fit with each local climate and culture emerged throughout Japan.
Today, miso is produced industrially in large quantities, and traditional homemade miso has become a rarity. In recent years, many new types of miso have appeared, including ones with added soup stocks or calcium, made with beans other than soy, or having reduced salt for health, among other varieties available.
The ingredients used to produce miso may include any mix ofsoybeans, barley, rice,buckwheat,millet,rye, wheat,hempseed, andcycad, among others. Lately, producers in other countries have also begun selling miso made from chickpeas, corn,azuki beans,amaranth, andquinoa. Fermentation time ranges from as little as five days to several years. The variety of Japanese miso is difficult to classify but is commonly done by grain type, color, taste, and background.
Many regions have their own specific variation on the miso standard. For example, thesoybeansused inSendaimiso are much more coarsely mashed than in normal soy miso.
Miso made with rice such asshinshumiso (信州味噌) andshiromiso (白味噌) are calledkomemiso (米味噌).
Miso's taste, aroma, texture, and appearance vary by region and season. Other important variables that contribute to a particular miso's flavor include temperature,fermentationduration, salt content, variety ofkōji, and fermenting vessel. The most common flavor categories of miso are:
Although white and red (shiromisoandakamiso) are the most common misos available, different varieties may be preferred in particular regions of Japan. In the easternKantō regionthat includes Tokyo, the darker brownishakamisois popular while in the westernKansairegion encompassingOsaka,Kyoto, andKobe, the lightershiromisois preferred.
A more nuanced breakdown of the flavors is as follows:
The distinct and unique aroma of miso determines its quality. Many reactions occur among the components of miso, primarily the Maillard reaction, a non-enzymatic reaction of an amino group with a reducing sugar. The volatile compounds produced from this reaction give miso its characteristic flavor and aroma. Depending on the microorganism in combination with the variety of soybean or cereal used, many flavor compounds are produced that give rise to the different types of miso. Fermentation products such asfuranonecompounds, including 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) and 4-hydroxy-2,5 dimethyl-3(2H)-furanone (HDMF) are novel flavor compounds of miso.HEMF is especially known for its sweet aroma and is very important for the sensory evaluation of the aroma of rice miso.
The unique sensory properties of miso are complex. The key factor in the final product's overall quality is the microorganisms' enzymatic activity. They use the composition of miso (rice, barley, and soybeans) to produce different pigments, flavors, and aroma compounds.
Proteolysisof soybean protein produces constituent amino acids that impart anumamitaste that enhances the relatively dull taste of soybean by itself.Soy protein contains a substantial amount ofglutamate, the salt of which is known as MSG ormonosodium glutamate, a popular ingredient used by food manufacturers to improve the taste of their products.The umami effect of MSG itself is one-dimensional. The umami taste of miso is multidimensional because of the myriad amino acids and fermentation products.
Barley miso is a traditional farmhouse variety made for personal use. Often called "rural miso", domestic barley is used more than imported barley. Containing glutamic acid and aromatic compounds such asferulic acidandvanillic acid, barley miso is distinguished by a characteristic flavor.
Miso's unique properties and flavor profile can be attributed to the compounds produced through the fermentation process. Miso, depending on the variety, consists of a starter culture calledkōji(麹), soybeans, and usually a grain (either rice, barley, or rye).The miso goes through a two-step process; first creating thekōji, and second thekōjiis combined with the other components, and the mixture is left to be enzymatically digested, fermented and aged.
Koji is produced by introducing themoldAspergillus oryzaeonto steamed white rice. This mold culture comes from driedA. oryzaespores calledtane-kōji(種麹,たねこうじ) or "starter koji" and is isolated from plant matter (usually rice) and cultivated.In the past, the natural presence ofA. oryzaespores was relied upon to create koji, but because of the difficulty of producing the culture,tane-kōjiis added almost exclusively in both industrial and traditional production of miso.Tane-kōjiis produced much in the same way as koji, but also has a small portion of wood ash added to the mixturewhich gives important nutrients to the fungus as well as promotingsporulation.
A. oryzaeis an aerobic fungus and is the most active fermenting agent in kojias it producesamylolytic, and proteolytic enzymes which are essential to creating the final miso product. Amylolytic enzymes such as amylase aid in the breakdown of starch in the grains to sugar and dextrin,while proteolytic enzymes such as protease catalyze the breakdown of proteins into smaller peptides or amino acids. These both aid in the enzymatic digestion of rice and soybeans. Depending on the strain ofA. oryzae, the enzymatic composition varies, thereby changing the characteristics of the final miso product. For example, the strain used to create the sweeter white miso would likely produce a higher content of amylolytic enzymes, while comparatively, soybean miso might have a higher content of proteolytic enzymes.
To create optimal conditions for enzymatic production and the growth ofA. oryzae, the koji's environment must be carefully regulated. Temperature, humidity, and oxygen content are all important factors in maximizing mold growth and enzyme production and preventing other harmful bacteria from producing. Once the koji has reached a desirable flavor profile, it is usually mixed with salt to prevent further fermentation.
Although other strains of fungi have been used to produce koji,A. oryzaeis the most desirable because of several properties, including the fact that it does not produceaflatoxin.
Miso typically comes as a paste in a sealed container requiring refrigeration after opening. Natural miso is a living food containing manybeneficial microorganismssuch asTetragenococcus halophilus, which can be killed by overcooking. For this reason, the miso should be added to soups or other foods prepared just before they are removed from the heat.  Using miso without any cooking may be even better.
Miso is a part of many Japanese-style meals. It most commonly appears as the main ingredient ofmiso soup, which is eaten daily by much of the Japanese population. The pairing of plain rice and miso soup is a fundamental unit ofJapanese cuisine. This pairing is the basis of a traditional Japanese breakfast.
Miso is used in many other types of soup and soup-like dishes, including some kinds oframen,udon,nabe, andimoni. Generally, such dishes have the title miso prefixed to their name (for example,miso-udon) and have a heavier, earthier flavor and aroma than other Japanese soups that are not miso-based.
Many traditional confections use a sweet, thick miso glaze, such asmochianddango. Miso-glazed treats are strongly associated withJapanese festivals, although they are available year-round at supermarkets. The consistency of miso glaze ranges from thick andtaffy-like to thin and drippy.
Soybean miso is used to make a type ofpicklecalledmisozuke.These pickles are typically made fromcucumber,daikon,napa cabbage, oreggplant, and are sweeter and less salty than the standardJapanese salt pickle.
Other foods with miso as an ingredient include:
Claims that miso is high invitamin B12have been contradicted in some studies.
Some experts suggest that miso is a source ofLactobacillus acidophilus.Miso is relatively high in salt which could contribute to increased blood pressure in the small percentage of the population with sodium-sensitiveprehypertensionorhypertension. Several studies using salt-sensitive hypertensive models and analyzing long-term intake have suggested that miso lessens salt's effects on blood pressure.