Instant Pot mushroom barley soup is incredibly flavorful with a rich, silky broth. This cozy barley soup is easy easy to make in your Instant Pot.
Gosh, I love this soup!
This vegetarian Instant Pot mushroom and barley soup is rich and hearty without feeling heavy. Pearl barley and mushrooms give the soup texture and flavor, both of which are enhanced by two secret ingredients: miso and soy sauce.
The salty umami flavors of soy sauce and miso paste pair perfectly with earthy mushrooms and pearl barley. These two ingredients add rich, complex flavor to make a cozy, really flavorful soup.
If this recipe sounds good, you'll also love miso mushroom pasta and miso butter sweet potatoes. Another fantastic recipe that uses miso paste as an ingredient is miso butter baked salmon.
Looking for more barley recipes? Try Crock Pot beef and barley stew or barley with eggs and spinach.
If you'd like to learn more about cooking barley, check out this recipe for how to cook barley.
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Why you'll love this soup
- Easy to make in your Instant Pot - very little prep
- So flavorful!
- Vegetarian/Vegan
- The rich flavor and texture will satisfy meat lovers too
Ingredients
Mushrooms: A mix of different mushrooms will give this soup the most flavor. Although you can just use button or white mushrooms if that's what available). I like a blend of cremini/button mushrooms and shiitake. You can also use baby bella mushrooms.
Pearl Barley: The cooking time for this soup is based on pearl barley (learn how to cook barley). You can substitute pearled or semi-pearled farro and keep the same cooking time.
Miso: White or yellow miso paste are the best choices for this soup. They both have a mild, slightly sweet and savory flavor that blends in wonderfully with the mushrooms and barley. You really need miso for this soup, or the flavor just won't be the same. Many grocery stores sell miso in the refrigerated section. You can also buy miso from Japanese markets and many online sources.
Soy Sauce: Soy sauce flavors the mushrooms instead of salt and adds more umami flavor to the soup. You can substitute tamari, Bragg liquid aminos, or Coconut Aminos. If you absolutely don't have any of these in your kitchen, you can skip this ingredient without drastically changing the soup. Just season the mushrooms with a pinch of salt and pepper.
Onion and Celery: Just a little bit, finely chopped, adds flavor to the soup.
Oil: I use olive oil. You can substitute canola/sunflower oil, avocado oil or unsalted butter.
Broth and Water: A combination of both vegetable broth and water creates the right balance of flavor. Don't use only vegetable broth, or the soup will be too salty. You can substitute in chicken broth or beef broth if you like.
How to Make Mushroom Barley Soup: Step-by-Step Instructions
(For detailed instructions and ingredient amounts, see the recipe card below)
Step 1: Roughly chop the mushrooms.
Step 2: Saute onion and celery, then add and saute the mushrooms.
Step 3: Drizzle soy sauce over the mushrooms and mix well. Add water, broth and barley. Cook the soup for 15 minutes on high pressure, with a quick release after 10 minutes.
Step 4: When the soup is done, combine 2 tablespoons of miso with ½ cup hot soup broth. Whisk well until smooth, then pour the miso back into the soup.
How to Add Miso Paste to Soup Broth
The main thing to know about adding miso paste to soup broth is that it should not be added when the soup first starts cooking.
For the best flavor and consistency, miso should be added when the soup has basically finished cooking and is no longer boiling or simmering.
First of all, miso paste doesn't blend well when dropped into boiling liquid. You might end up with chunks of miso that don't dissolve. Also, miso is a fermented food with micoflora and enzymes that would be destroyed in boiling water.
Here's how to add miso to soup:
- Scoop out a ½ cup of hot broth into a bowl. You can also use hot water.
- Add the miso paste to the bowl.
- Whisk until very smooth
- Slowly pour the miso back into the soup, stirring or whisking as you pour.
For more helpful tips about cooking with miso, check out Five rules for cooking with miso paste from misotasty.com. You can also read Bonnie Chung's cookbook, Miso Tasty.
Miso FAQ
Miso is a soybean paste that is made by fermenting soy beans with a culture called a "koji." Most fermented foods require a culture that comes from yeast, mold or good bacteria to jump start the fermentation process. The "koji" culture is derived from a grain, usually rice or barley. Salt is also added, which adds flavor and helps preserve miso.
The ingredient list for miso is usually soybeans, a rice or barley culture (koji), salt and water.
There are many versions of miso, but the three most common types of miso that you'll see in US supermarkets are white, yellow and red miso.
White and yellow are fermented for shorter periods of time and have a lighter, more delicate flavor. They are less salty than red miso and fairly interchangeable in recipes.
Red miso is fermented for a longer amount of time. It has a saltier, more assertive flavor.
Miso is a unique product that has been made in Japan for at least a thousand years. There is no equal substitute. Products that come close to replicating the salty, umami flavor of miso are soy sauce, fish sauce and mushrooms. Miso Master also sells chickpea miso which is soy-free.
A long time! The high salt content helps preserve miso and keep it fresh for a year or more after it is opened. The best way to store miso is in a covered container in the refrigerator.
FYI: I just bought a container of miso in September 2021, and the best buy date is April 2023. The manufacturer says that even after being opened, the miso will stay fresh through that date.
Miso is a great flavor booster. It can be used to make salad dressing, like for this couscous salad or miso coleslaw. It can flavor soups (especially miso soup) and add extra flavor and tenderizing properties to marinades. You can use miso to top miso butter salmon or miso butter sweet potatoes.
Yes, miso that is made from soybeans, salt and a grain-based culture is vegan.
However, be aware that some miso products also add dashi stock for flavor and dashi is not always vegan. Dashi can be made from kelp, but traditionally dried fish flakes (bonito) are also added.
More Instant Pot Soupo Recipes
📖 Recipe
Instant Pot Mushroom Barley Soup
Instant Pot Mushroom Barley Soup is incredibly flavorful. The secret ingredient is miso paste, which adds rich umami flavor. This barley soup is vegan and easy-to-make in your Instant Pot.
Total Instant Pot Cooking Time: 15 minutes to reach pressure + 15 minute cooking time + 10 minute quick release
- Prep Time: 15 minutes
- Cook Time: 15 minutes
- Total Time: 30 minutes
- Yield: 4 to 6 servings 1x
- Category: Soup
- Method: Instant Pot
- Cuisine: American
- Diet: Vegan
Ingredients
- ¼ cup olive oil
- ½ cup finely chopped onion
- ¼ cup finely chopped celery
- 8 to 12 ounces mushrooms*, roughly chopped into small pieces
- 1 tablespoon soy sauce
- 2 cups water
- 4 cups vegetable broth
- ½ cup uncooked pearl barley
- 2 tablespoons white or yellow miso
*You can use one type of mushroom or a mix of your favorite types. I use a mix of button/cremini mushrooms and shiitake when I make this soup.
Instructions
- Use the saute setting on the Instant Pot to warm the olive oil.
- Add the onion and celery. Saute until soft, about 5 minutes. Keep an eye on the onion so it doesn’t burn or stick to the pot.
- Add half of the mushrooms and cook for a minute or two, stirring frequently, until the mushrooms have cooked down and decreased in size.
- Add the remaining mushrooms and saute several more minutes, stirring frequently, until the mushrooms are very soft.
- Drizzle the soy sauce over the mushrooms and mix well.
- Add water, broth and pearl barley.
- Secure the lid and cook the soup for 15 minutes on high pressure.
- When the cooking time is complete, wait 10 minutes then do a quick release of steam.
- In a small bowl, whisk together 2 tablespoons of miso paste with ½ cup of the hot soup broth until very smooth.
- Slowly pour the miso into the pot of soup, stirring or whisking as you pour.
- Taste the soup. Sometimes I add 1 more tablespoon of miso (make sure to whisk it in a small bowl with broth before pouring it into the soup). You can also add salt and black pepper if the soup needs it.
Notes
Right when you open the lid, you might not think that the soup has enough barley. Just wait 10 minutes. As the soup sits, the barley absorbs the broth and plumps up, becoming more noticeable in the soup.
Stove top Instructions: You can also cook this soup on the stovetop. Follow the same instructions to saute the veggies in a soup pot, then add water, broth and barley. Simmer gently with a lid, stirring occasionally, for about 30 minutes until the barley is tender. Then follow the instructions above for adding miso.
Storage: This soup will stay fresh for up to 5 days in the refrigerator. You can also freeze the soup if necessary, but the barley gets softer after being frozen and defrosted.
It's okay to substitute beef broth for the vegetable broth.
This recipe was tested in a 6-quart Instant Pot
Tania
Such a great idea to add miso paste for that extra umami flvaour! Really loved this soup, great recipe!
Jovita
This soup looks super comforting. The weather is getting cooler so I'm definitely trying this one soon!
Kushigalu
Love the combination of flavors in this soup recipe. SO comforting and delicious. Thanks for sharing
Mirlene
Ahh, I see that Miso is the key here to this wonderful soup! This is a perfect way to have a tasty bowl of soup for this season.
Beth
That looks deeeeeeeeelish! I can't wait to try it! Of course I just love mushrooms and barley. So glad it is finally soup weather.