Miso (味噌) is a paste made of fermented soybeans and koji, a type of mold grown on rice and used as a fermenting agent. Miso paste can be used as a sauce base or a marinade, but it is most commonly and traditionally used in the making of miso soup.

Miso paste is said to have made its way to Japan in the 7^th century, in the Nara period of Japan, brought from China by Buddhist monks. It was around this time when the monks began to mix it with a plain bonito and kelp broth in order to make a filling soup. It wasn’t until the 15^th century that use of miso paste widened to marinades and sauce bases.

Miso paste comes in different types, the four most common being red, white, barley, and soybean miso. Red and white miso can be easily differentiated by sight, as they have a clear difference in color. Red miso has the longest fermentation time, one to two years, because it uses little to no koji to help speed up the fermentation process. Red miso has a saltier taste and is used for stews and the marinade of meat, poultry, and vegetables. White miso, on the other hand, uses a lot of koji to help speed fermentation, which means it can be made in months rather than years. White miso will taste swetter, and is used for lighter fare such as dressing bases and fish marinades.

Mugi Miso (麦みそ), or barley miso in English, and 100% soybean miso are less common than their red and white counterparts. Barley miso is made with barely grains and barely koji along with soybeans. It’s the saltiest type of miso paste, and is also the darkest in color. Because it’s not made with pure koji, it also takes anywhere from one to three years to ferment. It’s often used as a sauce or spread base because of its rich flavor. 100% soybean miso is made from only soybeans, and as such, it also takes a year or more to ferment. It’s usually used as a soup-flavoring agent.

One common type of 100% soybean miso is hatcho miso (八丁味噌). Hatcho miso is a dark variety of red miso that has fermented for a period of up to three years. It has a very balanced flavor and is good to use in many different recipes. Because hatcho miso is made from 100% soy, it has a much lower salt content than many other miso varieties, which shows in it’s light calm flavor profile.  Another type of miso often found in shops is saikyo miso (西京味噌). Golden-yellow in color, saikyo miso was made traditionally in the Kyoto/Kanto region of Japan. It’s naturally very sweet because of its low sodium content and is often used in dipping sauces and even baked goods.

Miso paste is high in protein and also contains fiber, lecithin, and saponin, all of which work to lower cholesterol and reduce artery blockage. Miso also contains a live culture yeast that helps it ferment. This live yeast promotes the growth of good bacteria, which can help you break down organisms that shouldn’t stay in the body; this can be especially useful after taking antibiotics of any sort. Miso also contains linoleic acid, a type of fatty acid, which helps stay soft and helps prevent extra pigment from forming, saving the skin from dark spotting. Some studies have found that despite being high in sodium, the sodium intake from miso doesn’t affect the body as adversely as other foods with equally high sodium content.

In general, fermented foods are very high in enzymes that are required by your body in order to carry out functions. As you age, your body’s ability to make and store enzymes decreases and consuming fermented foods help provide you with those essential enzymes. Fermented foods also help improve the body’s ability to absorb vitamins taken in from other foods both because it contains live lactobacilli, which assists the body in breaking down nutrients, and because the fermentation process itself partially breaks down the nutrients already in the food being fermented.

You can make your own miso paste at home with only a few ingredients and patience. Because miso paste is fermented, it can take anywhere from five to six months to properly finish, but the initial cook time only takes about two days. All you need to make white miso paste is regular salt, koji paste, and soybeans. The soybeans need to soak overnight, for at least 18 hours, until the beans inflate with water. After the beans soak they should be cooked for four hours or, if you have a pressure cooker, for 20 minutes. Once the beans have cooled enough to touch, they should be mashed by hand with a mortar and pestle, as the use of a food processor or blender would give them an odd texture. In a separate bowl, the koji and salt should be mixed well before it’s added together with the miso. Press the mix down flat as possible to remove any air, then cover it with a weighted lid then let it ferment in a cool, room temperature location for five to six months.

If you don’t want to make your own miso paste at home, it can be bought pre-made as well. At Asahi, you can buy each type of miso mentioned in this blog, including some that have dashi stock already mixed into the miso paste to easily make miso soup. A nice bowl of miso soup is a good compliment for any meal, and is generally eaten with every one, from breakfast to dinner. For a simple miso soup recipe you can look at our website, here.  Everything needed to make a delicious miso soup can be found at Asahi. For quick and easy miso soup Asahi also carries a large variety of instant miso soup. Just add to water and serve!