Shoyu Vs. Miso: How Do They Compare?

Shoyu and miso are both made from fermenting soybeans and other grains. They share a history that connects them to Ancient Chinese jiang, a soy paste. In the centuries since the invention of jiang, it made its way to Japan, where shoyu and miso have become key ingredients in that nation’s cuisine. Shoyu is just the Japanese name for soy sauce, a staple condiment, and ingredient in Japanese cooking for centuries; miso refers to the equally ancient and esteemed Japanese soybean paste. Let’s compare these two popular(and flavorful) ingredients.

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How does shoyu differ from miso?

Shoyu and miso have different consistencies. Shoyu comes in different varieties with a range of thicknesses, but all are liquid, while miso is always a thick paste.

Shoyu and miso are produced in different ways. They are made using a mold called koji. Kojis break down starches and convert them to sugars that can be fermented. The koji used for fermenting shoyu has historically been different from the koji for miso. The traditional koji for shoyu comes from soybeans only or a mix of soybeans and wheat. The koji used to ferment miso is usually from grain — rice, barley, or wheat — except in the case of soybean miso.

In shoyu fermentation, the koji digests and liquefies the soybeans and wheat for longer and to a much greater degree than in miso fermentation.

The different fermentation processes lead to differences in flavor between shoyu and miso. Shoyu has a richer umami flavor than the relatively mild and subtle miso. While miso’s flavor intensity can vary based on how long it has been fermented, it never attains the strong concentrated notes of shoyu.

Can you use shoyu as a substitute for miso? And vice versa?

You can use shoyu as a substitute for miso in some Japanese dishes but only in the sense that it will result in an equally enjoyable dish, not that it will create identical results. Shoyu is darker and more flavorful, so you should expect a different flavor and appearance.

For example, shoyu ramen and miso ramen are both traditional forms of ramen, but they look nothing alike and do not taste the same despite each being salty and rich in umami flavor.

Similarly, miso works as a shoyu substitute if you aren’t trying to replicate the shoyu taste and color. Miso works best as a shoyu substitute in Western applications where either Japanese ingredient may be used to provide umami.

When should you use shoyu? And when should you miso?

There are different kinds of shoyu, and each has its ideal applications. Dark, intense shoyu is used in marinades and dipping sauces. Lighter and thinner shoyus get used in stir-fry sauces, hot pots, and for flavoring vegetables. Lighter soy sauces may also be used on Japanese-style fried rice. Outside Japan, shoyu may be used in marinades for grilled meat or to intensify the gravy for a roast.

Miso is great for making ramen broth and other kinds of soup. The more flavorful red miso is great for intensifying the umami properties of stews and other braised dishes. White miso is the less flavorful variety made with a higher proportion of rice and is suitable for milder sauces and soups. White miso is perfect for introducing people to miso.