What is Miso Soup?
Miso Soup or Misoshiru (味噌汁) is a Japanese soup that can accompany a bowl of rice for any meal of the day, however, it’s a staple of Japanese breakfasts. It’s made with dashi, miso, and solid ingredients such as vegetables, tofu, and seaweed.
Types of Miso
Miso is a fermented seasoning that’s typically made from soybeans, koji, and salt. Koji or Aspergillus Oryzae is a filamentous fungus that’s propagated on grains such as rice or barley and is the organism responsible for fermenting the soybeans. Varying the ratio of these three ingredients as well as the length of time the miso is fermented for, can result in vastly different flavors of miso. This is probably why miso is region-specific, and there are hundreds if not thousands of different types of miso. Most miso can be categorized into one of three categories based on its color, which is determined by the length of time it’s fermented. Unfortunately, the terminology is a little confusing, resulting in a lot of mislabelling happening in English.
White Miso (白味噌 – Shiromiso)
While the color is more of a light blond than white, shiromiso is the lightest in color thanks to its very short fermentation time (as little as 2-3 days). It’s made with two to three times more rice koji than other types of miso, and it contains two to three times less salt. This makes the miso very mild, with a natural sweetness thanks to koji’s ability to convert starches into sugar. White miso is most commonly used in the cuisine of Kyoto, and the most well-known brand is Saikyo Miso.
In the US, I’ve found that a lot of miso labeled “white miso” is actually more like yellow miso. That’s why the best way to identify it is by its appearance. Aside from having a lighter color, white miso is much smoother than other types of miso, and because of the short fermentation time, it has a much higher moisture content, rendering it very soft. I’ve also sometimes seen it labeled as “sweet white miso.”
Yellow Miso (淡色味噌 – Tanshokumiso)
Tanshokumiso literally translates to “light-colored miso,” but I think this is what led to this category of miso being mislabeled as “white miso” in the US. That’s why I prefer calling it “yellow miso.” The vast majority of miso falls into this category, and it can range in color from tan to medium brown with a fermentation time of anywhere from 6-10 months. Yellow miso has a salt content of 10-12% which makes it two to three times more salty than white miso. This type of miso can also be made with either rice koji or barley koji which has an impact on its taste. I find that miso made with barley koji tends to be nuttier while miso made with rice koji tends to be more mellow and a little bit sweet.
Red Miso(赤味噌 – Akamiso)
Red miso is the final category and encompasses all the darker types of miso. The long aging time of up to 2 years results in a significant amount of Maillard browning, which not only gives red miso its dark brown to almost black hue, it also develops a nutty complexity with loads of umami. The longer fermentation time also results in more evaporation, which typically makes red miso firmer and saltier than its lighter counterparts.
Although there are regions all over Japan that use red miso, the area around Nagoya is most typically associated with it. Hatcho Miso is perhaps the most famous brand, and it’s made with just soybeans, salt and water and does not include any grains. Hatcho miso is fermented for two years in Japanese cedar barrels under a pyramid of river rocks which gives it a very firm dry texture.
Flavored Miso
I thought it’s worth mentioning that miso should only contain soybeans, koji (rice or barley), and salt. There are other flavored miso seasonings which should not be used for miso soup. These days, there is also a product called dashi miso, which includes ingredients such as bonito extract and kelp. The idea here is that the miso itself contains dashi concentrate so you can make miso soup by just adding water. I am not a fan of these types of miso as they limit things you can use the miso for, and they also tend to include MSG.
Miso Soup Ingredients
Dashi
I see a lot of recipes for Miso Soup out there using water as the base. This is like making chicken soup with just water and salt without the chicken. Dashi is a defining component of miso soup, and along with miso, it’s the only other required ingredient. You can read all about how to make dashi here, but it’s typically made with a combination of kelp and some kind of dried fish. For plant-based dashi, you can use the kelp stock without adding dried fish, or you can rehydrate shiitake mushrooms in it, which will give your dashi a ton of umami.
Vegetables
I like my miso soup to be loaded up with so many veggies that it almost looks like a stew. Vegetables not only add color, nutrients, and fiber to the soup, they also contribute to the flavor of the soup. Because I like my miso soup to have a subtle sweetness, I tend to add at least one sweeter vegetable such as carrots, onions, sweet potato, or kabocha. Here are just a few suggestions on the types of vegetables you can add.
- Root vegetables – whether you’re talking carrots, sweet potatoes, onions, or burdock, root vegetables contribute both flavor and bulk to your miso soup. These tend to take the longest to cook through, which is why I like to add them at the very beginning.
- Squashes – Kabocha, butternut squash, and acorn squash are a few that come to mind right away, but zucchini and other softer squash will work as well. Add these in at the beginning as they take a while to cook through.
- Eggplants – Despite being relatively soft, eggplant requires a surprising amount of time to cook through, so I usually recommend adding them relatively early on, unless you’re planning to add some very tough root vegetables.
- Green vegetables – Green veggies like green beans, okra, asparagus, broccoli shouldn’t go in at the beginning, or they’ll end up losing their color and getting mushy. That being said, they need more time to cook than leafy greens, so these go into the soup in somewhere in the middle.
- Leafy greens – You can use almost any leafy green ranging from spinach to cabbage, to kale, to molokhia. Unless it’s something I want very tender such as cabbage, I usually put leafy greens in at the very end to preserve their color.
- Sea Vegetables (a.k.a. seaweed) – In Japan there are dozens of varieties of seaweed and most of them are fair game for adding to miso soup. The most common one is wakame. Seaweed cooks very quickly and will turn to mush if you overcook it, which is why I recommend adding it at the very end.
Tofu
Pretty much anything tofu-related is fair game here, including ganmodoki (tofu fritter), aburaage (thin fried tofu), atsuage (thick fried tofu), koyadofu (freeze-dried tofu), and of course plain old tofu in all its firmnesses. If the tofu has been fried, I usually put it in just before adding the miso, if it has not been fried I’ll add it after adding the miso. This is because raw tofu can fall apart while you’re trying to get the miso to dissolve.
Garnishes
Garnishes such as scallions, aonori, and mitsuba can be added straight into the bowl when you serve the miso soup.
Vegan Miso Soup
Although most dashi includes dried fish, making miso soup plant-based is as simple as using plant-based dashi. You can head to my post about making dashi from scratch to learn about making a plant-based dashi. As for the miso, most miso is vegan-friendly, but just be sure to read the ingredient label to make sure it doesn’t include any fish.
How to Make Miso Soup
Once you have all the ingredients the process for making miso soup is straightforward. The first step is to cook the hard ingredients such as carrots and potatoes in dashi until they’re tender.
Then you just have to add the miso. I like to dissolve the miso in a ladle before adding it to the soup, so you don’t end up with clumps of undissolved miso. Boiling the soup after the miso has been added will cause it to separate, which is why it’s important to turn down the heat before you add the miso. Because different types of miso can have varying levels of salinity, it’s important to taste the soup as your dissolving the miso to ensure you don’t add too much.
After the miso has been added, you can add delicate things such as tofu, as well as any leafy greens or sea vegetables you plan to add.
Finally, garnishes such as scallions and mitsuba can get added straight to the bowl when you serve your soup.
Units
Ingredients
- 1 ½ cups dashi
- 75 grams kabocha pumpkin sliced
- 50 grams onion sliced
- 2 tablespoons white miso add more to taste
- mitsuba chopped, for garnish
Instructions
- Add the dashi, kabocha, and onion to a pot bring to simmer. Cook until the kabocha is tender.
- Turn down the heat and add the miso, dissolving it in a ladle first before adding it to the soup.
- Serve the white miso soup garnished with mitsuba.
Nutrition
Units
Ingredients
- 1 ½ cups dashi
- 30 grams carrots thinly sliced
- 1 tablespoon miso add more to taste
- 90 grams soft tofu cubed
- 40 grams spinach chopped
Instructions
- Add the dashi and carrots to a pot and simmer until the carrots are tender.
- Turn down the heat and add the miso, dissolving it in a ladle first to avoid clumps of miso.
- Add the tofu and spinach. The miso soup is ready when the tofu has heated through.
Nutrition
Units
Ingredients
- 1 ½ cups dashi
- 75 grams eggplant
- 30 grams aburaage thin fried tofu
- 1 tablespoon miso add more to taste
- scallions chopped, for garnish
Instructions
- Add the dashi and eggplant to a pot and bring to a simmer. Cook until the eggplant is tender.
- Add the aburaage and cook until it’s heated through.
- Dissolve the miso in a ladleful of soup. Serve the miso soup and garnish with scallions.
Nutrition
Barbara Raber says
I have tried 3 or 4 different miso pastes, but all of them are way too salty for my taste. I like salt but not anything over salty. Is there a way for me to tone it down or is there a brand that is not too salty. The last one I bought from a health food store and had a low sodium content but was still quite salty.
Marc Matsumoto says
Hi Barbara, just reduce the amount of miso you add to the soup. There are a couple of other things to consider 1) Are you using powdered Dashi stock? If so, these tend to include a lot of salt, so this could be contributing to the problem. The solution here is to make your own dashi from scratch (recipe linked above). 2) White miso has significantly less salt than other types of miso so this is another option (though you should read my headnotes above as a lot of miso brands mislabel their miso as “white miso” in the US when in fact they are yellow miso.
Bethy says
I love your site and your recipes, Marc!
Question: Is it true that one should never boil miso due to it losing all nutrition?
Marc Matsumoto says
Thanks Bethy! Regarding your question, miso will not lose all nutrition if you boil it. The main reason for not boiling miso is because it will cause it to separate (if you’ve ever seen a bowl of miso soup that’s separated into a clear layer and miso layer at the bottom, the soup was likely boiled.) Another reason why it’s not boiled is because boiling it will kill any live probiotics it may contain. That being said, adding it to hot soup in general (regardless of whether it is boiling or not) will probably kill the probiotics anyway, and most miso sold in the US is likely to to have been pasteurized (i.e. had all the probiotics killed), as miso with live cultures have a very short shelflife.