Dashi is a difficult ingredient to replace. Many Japanese food experts will tell you that it is impossible and that you would be better off not trying. To a certain extent, they are right. The complex umami character of dashi is difficult to replace; however, there are ingredients that can provide you with a similar result. None of them are perfect, but they all get the job done. Here are some of the best dashi substitutes:
Your best bet: Monosodium glutamate (MSG)
The point of using MSG in your food is to boost the umami flavor, which is also the point of using dashi. Monosodium glutamate was invented in the early 20th century when a Japanese scientist figured out how to isolate glutamate from the same type of seaweed used to make kombu dashi.
These days, MSG is made from a variety of ingredients including soybeans but still provides the same flavor profile in dishes. Glutamate is what is responsible for dashi’s meaty taste. Whether you use dashi or MSG, you are just adding glutamate to your food.
One of the major benefits of MSG as a dashi substitute is that it is usually easier to find than other dashi substitutes. Kombu for making dashi is not always easy to find in the West, neither is bonito. In comparison, MSG is easy to find in both Western-style grocery stores and Asian stores. It is a great option when you need a dashi alternative right away.
A decent second choice: Soy sauce
One of the most important sources of the umami flavor in many Asian cuisines, soy sauce will work as a substitute for dashi if you can overlook the color. Even light soy sauce will tinge a pale dish with brown. The flavor of soy sauce is also not as clean as the flavor of dashi; however, it can provide some of the desired umami profile.
Because dashi and soy sauce are often used together in Japanese recipes, you may be able to replace the dashi component by simply doubling the soy sauce.
In a pinch: Make your own dashi
Dashi is one of those Japanese preparations that appear to be extremely simple but that actually requires considerable experience to make well. You may be able to make a passable substitute if you can find the ingredients and are willing to spend some time learning the correct technique. You will have to steep and filter a combination of kombu and bonito flakes to arrive at the simple broth.
Western-style broths and stocks are similar and may be used in place of dashi. Chicken broth is an especially good option as a dashi substitute. You should opt for a lightly flavored broth or stock to get something more like dashi. Chicken stock won’t give you the briny flavor that you would get from seaweed or fish, but it will give a strong umami character to a dish. While a stock or broth made from scratch will be the better option, you may get a passable result from one made from powder.
Dried shiitake mushrooms can provide an umami flavor and Japanese cooks sometimes use them to make dashi. You rehydrate them and use the soaking liquid to make dashi or add them directly to a savory dish in place of dashi to enhance the umami properties.