Miso (みそ or 味噌) is a traditional Japanese seasoning produced by fermenting rice, barley and/or soybeans, with salt and the fungus kōjikin (麹菌), the most typical miso being made with soy. The result is a thick paste used for sauces and spreads, pickling vegetables or meats, and mixing with dashi soup stock to serve as miso soup called Misoshiru (味噌汁), a Japanese culinary staple. High in protein and rich in vitamins and minerals, miso played an important nutritional role in feudal Japan. Miso is still very widely used in Japan, both in traditional and modern cooking, and has been gaining world-wide interest. Miso is typically salty, but its flavor and aroma depend on various factors in the ingredients and fermentation process. Different varieties of miso have been described as salty, sweet, earthy, fruity, and savory, and there is a very wide variety of miso available.
The taste, aroma, texture, and appearance of miso vary by region and season. Other important variables that contribute to the flavor a particular miso include temperature, duration of fermentation, salt content, variety of kōji, and fermenting vessel. The most common flavor categories of miso are:
- Shiromiso, "white miso"
- Akamiso, "red miso"
- Awasemiso, "mixed miso"
Although white and red (shiromiso and akamiso) are the most common types of miso available, different varieties may be preferred in particular regions of Japan. In the eastern Kantō region that includes Tokyo, the darker brownish akamiso is popular while the western Kansai region encompassing Osaka, Kyoto, and Kobe prefer the lighter shiromiso. Hatchomiso is favored in the Tokai area.
Miso typically comes as a paste in a sealed container requiring refrigeration after opening. Natural miso is a living food containing many beneficial microorganisms which can be killed by over-cooking. For this reason, it is recommended for miso to be added to soups or other foods being prepared just before they are removed from the heat. Using miso without any cooking may be even better. Outside of Japan, a popular practice is to only add miso to foods that have cooled in order to preserve kōjikin cultures in miso. Nonetheless miso and soy foods play a large role in the Japanese diet and many cooked miso dishes are popularly consumed.
The ingredients used to produce miso may include any mix of soybeans, barley, rice, buckwheat, millet, rye, wheat, hemp seed, and cycad, among others. Lately, producers in other countries have also begun selling miso made from chickpeas, corn, azuki beans, amaranth, and quinoa. Fermentation time ranges from as little as five days to several years. The wide variety of Japanese miso is difficult to classify, but is commonly done by grain type, color, taste, and background.
- mugi (麦): barley
- tsubu (粒): whole wheat/barley
- genmai (玄米): brown rice
- moromi (醪): chunky, healthy (kōji is unblended)
- nanban (南蛮): mixed with hot chili pepper for dipping sauce
- taima (大麻): hemp seed
- sobamugi (蕎麦): buckwheat
- hadakamugi (裸麦): rye
- nari (蘇鉄): made from cycad pulp, Buddhist temple diet
- gokoku (五穀): "5 grain": soy, wheat, barley, proso millet, and foxtail millet
Many regions have their own specific variation on the miso standard. For example, the soybeans used in Sendai miso are much more coarsely mashed than in normal soy miso.
Miso made with rice such as shinshu (yellow miso) and shiro are called kome miso.