Miso is deeply ingrained in Japanese food culture, and people outside the country are probably more familiar with it in the form of soup. Whenever you order a teishoku (meal course) at a restaurant, it is usually served with miso soup as a side. It is also common to see it when having a traditional breakfast. It is one of the core dishes and fundamentals of Japanese cuisine and can be used in food as simple as ramen, but also as delicate as kaiseki. It can also be a deep expression of love. There’s a saying that when a person says “Would you make miso soup for me?”, the underlying meaning is actually “Would you marry me?” It shows how closely and dearly miso is tied to the daily life of Japanese people.
You may not be aware, but there are several different types of miso. Depending on the amount and the type of ingredients used and the length of fermentation, it can make a big difference in taste, color, and texture. It is primarily made of soybeans, koji, and salt, which provides great nutrition to the body. Each region has a different preference for miso as well. There are three main types: kome (rice), mugi (barley), and mame (soybean).
Kome Miso
Kome miso is made from malted rice, soybeans, and salt. The process by which it is made starts by boiling and steaming the soybean, then pressure cooking it. As for the rice, it needs to be steamed first, then mixed with koji starter to turn it into rice malt. Then, mix the rice malt with soybean, season it with salt and water, and let it fermentate and age. Depending on the length of fermentation, we will get either shiro (white) miso or aka (red) miso. The white version has a shorter fermentation period of 2 to 8 weeks and is known for its smooth, sweeter taste and rich flavor, which is great for seasoning senbei. The most well-known brand is “Seikyo” which originated in the Kansai area and is renowned for its high content of malted rice that creates a sweet flavor.
On the other hand, red miso has a longer fermentation period of 1 to 3 years. While being stored under a certain temperature and humidity, the Maillard reaction will take place, which darkens the color and makes it more flavorful. This variant has a strong salty flavor with a slight sweetness and bitterness. Since it contains a lot of salt and little sugar, it can be stored at room temperature indefinitely with the flavor growing richer as time goes on. As eating habits have a close relationship with the climate, usually the cooler the area is, the stronger the flavor of food. That being said, the northernmost prefecture of Japan, Hokkaido, is most famous for producing aka miso.
Mugi Miso
Mugi miso is made from malted barley, soybeans, and salt. It shares the same making process as kome miso but substitutes rice with barley. It has a darker color than kome due to its longer fermentation period. The defining characteristics are its sweetness and graininess where you can feel the barley grains. It can be eaten raw, so it is often used to make cold dishes. Since it has to follow the harvest season of barley, this style is usually made in winter. The Seto Inland are most famous for producing mugi miso, especially in Ehime prefecture. Because it contains more malted barley, there is a stronger scent and a sweeter taste.
Mame Miso
Mame miso is made from unmalted soybeans, malted soybeans, and salt. It begins by steaming soybeans, and then mixing them with koji starter to get soybean malt. The soybean malt is then pressed and mixed with salt water to let it fermentate and age. It usually has a fermentation period of 3 years, and has a dark reddish-brown color. It is famous for its strong flavor that is salty with slight bitterness. Mame miso is most popular in the Tokai area, where they produce different styles and brands. It also plays an important role in kaiseki.
Though these are all miso, the differences in ingredients, and fermentation times can vastly alter the taste. Miso is complicated because it requires so much time and effort to be put into making it, but it is also simple because incorporating it into your cooking is easy. You can easily find miso paste sold in Japanese supermarkets with a wide selection of choices available. A company I really recommend is Hikari Miso, who we had the privilege of conducting an interview with which you can read here! Whether you prefer paste made from rice, barley, or soybeans, or if you prefer a sweeter or saltier taste, you’ll be sure to find one that is to your liking. Next time you visit Japan, try and see if you can spot the difference in miso soup from different restaurants!