Miso Mushroom Barley Soup is a hearty, satisfying vegan soup loaded with chunky vegetables and a rich, savory broth. Umami-forward ingredients like miso and balsamic vinegar deepen the flavor, while pearl barley adds comforting chew and body. It’s an easy, delicious plant-based dinner that pairs beautifully with soft dinner rolls or cornbread for soaking up the tomato-tinged broth.
This soup is excellent served as a starter, a main course for dinner, or for lunch. It reheats well and keeps in the refrigerator for up to a week, making it a reliable option for meal prep.
Ingredient Notes
- Mushrooms: Use two varieties for a more complex flavor and a pleasing contrast of textures. Cremini (baby bellas) and shiitake work particularly well — shiitake offer a meatier bite while cremini add chewiness.
- Barley: Pearl barley takes longer to cook than quick grains, but its nutty, tender chew is worth the wait and contributes body to the soup.
- Flavor boosters: Garlic, onion, miso, tomato paste and a splash of balsamic vinegar layer savory, sweet-tart, and umami notes to let the mushrooms shine.
Make it
Begin by prepping the vegetables: dice the onion, carrot and celery. Thinly slice the mushrooms and mince or finely grate the garlic.
Mix the miso with ½ cup of water and set aside. Whisk or stir until it’s fully dissolved and smooth so there are no lumps.
Heat a large soup pot or Dutch oven over medium. Use a little broth, olive oil, or water to sauté the diced onion until it begins to soften. Add the diced carrot and celery, season with salt and pepper, and cook the vegetables, stirring occasionally, for about 5 minutes.
Swirl in another tablespoon of liquid if the pan is dry, then add the garlic and tomato paste. Stir and cook over medium-low heat so the paste caramelizes slightly and the garlic becomes fragrant, about 2 minutes.
Add the sliced mushrooms to the pot — it will look like a lot at first, but they quickly shrink as they release their liquid. Stir frequently while the mushrooms break down and the tomato paste blends into a sauce.
Cook until the mushroom volume reduces to roughly one-third of its original size and most of the moisture has evaporated, about 5 minutes.
Keep stirring so nothing sticks. Once the vegetables have reduced in size, add the rinsed and drained pearl barley.
Pour in 6 cups of water or vegetable broth and bring the pot to a boil. If needed, add another cup of liquid so the vegetables and barley are fully submerged.
Reduce heat to a gentle simmer and cook for about 45 minutes, until the mushrooms are tender and the barley is cooked through but still slightly chewy.
Turn off the heat and stir in the prepared miso mixture and 1 tablespoon of balsamic vinegar. Taste and adjust seasoning as needed.
Garnish with fresh parsley or other herbs and serve warm.
Store leftovers in an airtight container in the refrigerator for up to one week, or freeze for up to three months. Reheat gently over medium-low heat, stirring occasionally, until warmed through.
Debra’s Pro Tips
- Don’t rush the simmer: the soup needs about 45 minutes for the flavors to develop and for the barley to cook; most of that time is hands-off.
- If reheating stored soup, the barley may absorb extra liquid. Add a splash of water or broth while reheating and taste for seasoning — a little more balsamic or salt can brighten the flavors.
📖 Recipe
Miso Mushroom Barley Soup
Equipment
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Small whisk (for diluting miso)
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Large soup pot or Dutch oven
Ingredients
- 1 large red onion diced
- 2 large carrots diced
- 2 stalks celery diced
- 3 cloves garlic minced
- ½ teaspoon salt
- ½ teaspoon ground black pepper
- 2 tablespoon tomato paste
- 1 lb shiitake mushrooms sliced
- 1 lb cremini mushrooms sliced
- ¾ cup pearl barley rinsed and drained
- 6 cups water or vegetable broth
- 1 tbsp light miso paste
- 1 tablespoon balsamic vinegar
Instructions
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Prep veggies: dice onion, carrot and celery. Mince the garlic. Clean mushrooms with a damp towel and thinly slice.
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Heat a large pot over medium. Sauté the onion in a splash of broth, oil, or water for about 2 minutes. Add the celery and carrot with salt and pepper and continue to sauté until softened, about 3 more minutes.
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Add an extra tablespoon of liquid if needed, then stir in the garlic and tomato paste. Cook, stirring, until fragrant and well combined, about 2 minutes.
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Add all the sliced mushrooms and gently stir. They will release moisture and shrink; continue cooking until reduced to about one-third of their starting volume, about 5 minutes.
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Stir in the rinsed barley and pour in 6 cups of water or broth. If necessary, add another cup of liquid so everything is submerged.
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Bring to a boil, then reduce to a gentle simmer. Cook about 45 minutes, until the barley is tender with a little bite and the mushrooms are fully cooked.
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While the soup simmers, dissolve the miso in ½ cup water using a small whisk or fork until smooth.
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Turn off the heat, stir in the miso mixture and the balsamic vinegar, garnish with fresh parsley, and serve hot.
Notes
Reheat: Gently warm over medium-low heat, stirring occasionally, until bubbling.
Nutrition
Note
Nutrition estimates were calculated with online tools. For the most accurate values, calculate nutrition using the exact ingredients and brands you use.