In the soy foods family, tofu is the popular teenager, who is friends with the jocks and the theater kids alike. Natto is the middle child who marches to the beat of their own drum, and miso is the sweet and sensitive youngest child who holds the family together, despite their quiet temperament.

You might be familiar with miso soup as a first course option at Japanese restaurants, but miso can also be added to a variety of other dishes. Miso is rich in history, nutrients, and variety. Let’s learn what miso is and the many benefits of adding miso to your diet.

What Is Miso Paste?

Miso is a paste made from fermented soybeans, water, salt, and a type of culinary mold called koji, which is itself made from fermented soybeans but can also be made by fermenting grains or rice. Initially reserved for Japanese nobility, miso has existed for approximately 1,300 years. Today, it is a staple of Japanese cooking that adds flavor and nutrients to soups, stews, marinades, and more.

How Is Miso Made?

Before you can have miso, you must have koji. Miso makers typically prepare koji two days before they use it to make miso.

The miso making process begins in earnest by soaking soybeans in water for 15 hours. After soaking, the soybeans are mashed. Once the soybean mash has cooled to 86 degrees Fahrenheit, it is mixed with koji, salt, and water left over from the steaming process until it achieves a dough-like consistency. The mix is added to an air-tight fermenting container and sealed. Miso makers spray the container with liquor to prevent mold from growing.

Traditionally, the mixture is kept away from direct light for six months to one year if it’s made in the winter, or three months if it’s made in the summer. This is because fermentation occurs more slowly in lower temperatures, lending the finished product a more complex flavor. Early miso makers reasoned that late fall or early spring is prime miso season because the air is cold enough to be relatively free from microorganisms, but not so cold that it inhibits fermentation. Today’s miso makers have the benefit of modern modes of climate control, so their work is less reliant on the seasons.

Different Types of Miso

Variations in fermentation timelines, soybean preparation, and koji ingredients contribute to a range of miso varieties. Light miso, which typically refers to white or yellow miso, and dark miso are the two main categories of miso paste.

White Miso: White miso, or shiro miso, is made from rice koji and skinless soybeans that have been boiled or braised. Fermented for a shorter amount of time compared to other miso varieties, white miso is the mildest miso. Its subtle sweetness makes white miso a perfect base for soups, hotpot, and marinades. White miso also adds umami, a savory taste sensation, to glazes for fish, meat, and delicate plant-based proteins. It is even used as a glaze or topping in desserts, such as bread pudding and pineapple upside down cake. Fun fact: umami translates to “yummy” in Japanese!

Yellow Miso: Yellow miso, otherwise known as shinshu miso, is made from barley koji that sometimes contains a small amount of rice. In yellow miso, skinless soybeans are steamed, rather than braised or boiled. Yellow miso is fermented for a longer time than its white counterpart. Its earthy flavor lends itself to savory dips.

Dark/Red Miso: Though it ranges in color from red to chocolate brown, dark miso is often labeled as red miso. Dark or red miso is made by fermenting soybeans, including their skin, with koji that has a higher concentration of barley or other grains compared to the koji used to make yellow miso. Red miso is also fermented for a longer time than white or yellow miso. Salty, nutty, and hearty, red miso is used as an ingredient in Japanese curry, beef stew, and dark-hued sauces to intensify flavor.

What Are the Health Benefits of Miso?

Miso not only adds a kick or color to dishes, but it also adds nutrients that support the health of key body systems and can help prevent chronic diseases. Here are some of the biggest health benefits of eating miso:

Contains Essential Nutrients: Miso is a low-calorie source of nutrients such as protein, fiber, manganese, and Vitamin K. Protein helps our bodies build muscle mass and stay full after meals longer. Fiber aids digestion. Manganese supports brain and nerve function, and Vitamin K promotes circulatory health. In addition, fermented foods, like miso, help the body absorb nutrients more easily.

Provides Probiotics: Miso contains live and active cultures, making it a non-lactose source of helpful probiotics. It’s a great probiotic option for vegans, people living with lactose intolerance, or those who simply want to expand their diet and reap the benefits of probiotic foods. Indeed, research links consumption of foods containing probiotics to health benefits including a stronger immune system, enhanced digestion, better cognitive health, and improved mood regulation. Consumption of fermented foods, like miso, support gut-brain connectivity, which can influence anxiety and depression.

May Lower Blood Pressure: With salt being one of its main ingredients, miso doesn’t seem like an obvious food option for someone looking to reduce or maintain their blood pressure level. However, miso’s unique blend of ingredients come together to promote cardiovascular health. Research finds that the salt contained in miso does not raise blood pressure, as expected, due to the way it interacts with the other ingredients during the fermentation process. In fact, miso contains antihypertensive factors and helps to prevent organ damage and promote antioxidant activity. 

May Reduce the Risk of Certain Cancers: Miso’s isoflavone content is thought to reduce the risk of cancers, including stomach and breast cancer. The link between miso consumption and a reduced risk of breast cancer is especially strong in post-menopausal women.

How Can I Add More Miso to My Diet?

A lowkey, but integral member of the soy foods family, versatile miso adds subtle complexity and vital nutrients to dishes across categories and cultures.

Weeknight Dinner Ideas: Healthy weeknight dinners don’t need to be elaborate. The following recipes come together quickly and offer two different takes on soy miso dressing. Serve them as a main course for a light dinner or side by side for a more substantial meal:

Miso-Based Crowd Pleasers: Invite friends and family to join in benefitting from miso’s unique flavor and impressive nutritional profile by serving classic crowd pleasers like guacamole and pasta salad with a special soy twist:

Miso: An Unlikely Powerhouse

Miso’s subtlety belies exceptional versatility and an outstanding nutritional profile. True to its paste consistency, miso is the glue that holds the body together, bolstering cardiovascular function, cognition, digestion, and immune defense to improve overall health.

Miso joins other members of the soy foods family in being an accessible, healthy, and flexible addition to a well-rounded diet. It can serve as a foundation for dressings, dips, glazes, and marinades as well as comforting soups and stews.

Want to increase your daily intake of heart-healthy soy? Learn how to make healthy snacks using soy ingredients that can subtly enhance your favorite bites.