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How Long Does Miso Soup Last? Does Miso Soup Go Bad?

Miso soup is a famous Japanese soup and comfort food that is easy to prepare and is considered one of the healthiest soups in Japan and throughout the world, because it is packed with antioxidants, vitamins, proteins and minerals.

If you purchased miso soup from your grocery store or a restaurant for a recipe, there’s a high chance that you have leftovers since most cuisines don’t require lots of it and you’re wondering, “How long does miso soup last?”.

It is important to understand the shelf life of this soup because if it goes bad, it may cause serious health issues, like stomach aches, vomiting, diarrhoea among others.

Keep reading to find out the shelf life of Miso soup and how to keep it from going bad.

What’s Miso Soup?

whats miso soup

Miso soup is a combination of dashi (fish broth), various vegetables and miso paste (fermented soybeans, rice malt or barley).

It is popular worldwide mainly because of its health benefits and its versatility as there are so many variations of it.

In terms of taste, the fermented miso paste gives the soup its strong and mature flavour and salty taste.

Many people tend to think that the presence of the miso paste which is highly salty with antimicrobial properties makes the soup resistant to spoiling.

Although the paste is resistant to bacterial growth, the other miso soup ingredients can easily go bad thus offing the whole batch.

Some of the benefits of consuming miso soup are that; provides the body with important vitamins and minerals like zinc, manganese, vitamin K, calcium and protein.

These minerals aid in supporting structures like bones and the nervous system.

Additionally, it improves digestion due to the high levels of probiotics, strengthens the immune system, lowers cholesterol and improves mental health.

How Long Does Miso Soup Last? Does Miso Soup Go Bad?

how long does miso soup last does miso soup go bad

The longevity of miso soup is dependent on whether it has been opened (if it was in a can) and the temperature.

  • If stored in the refrigerator, the soup can last between 2 and 3 days provided that it is well covered to keep bacteria away.
  • If stored in the pantry at room temperature, miso soup can only last for several hours, between 2 and 6 hours. It is advised to consume it immediately after preparation or properly store it away in the refrigerator. .
  • Miso soup can be frozen and if done properly, it’ll last for about 2 to 3 months. .
  • An unopened can of miso soup may not go bad per se, but it’ll continue fermenting and losing its quality with time. .

It is important to note that the ingredients used in preparing the soup will also affect its longevity.

It is therefore difficult to give an exact amount of time that’ll take before your soup goes bad since there are many variations with different condiments.

Also, the longer you store it, the more flavours it’ll lose in the long run.

The timelines provided above are the safest general rules of thumb and they apply to store-bought, restaurant leftover and homemade miso soup.

If not stored properly in well-sealed cans or left out for long, miso soup will grow mould and develop a bad smell due to bacteria contamination.

Therefore, always ensure you store it in tightly sealed containers at cold temperatures, below 7 degrees Celsius.

Again, although miso soup has miso paste in it that is resistant to bacteria, it can still go bad because it contains other perishable ingredients like vegetables, tofu, potatoes, bean sprouts and mushroom.

How to Tell If Miso Soup is Bad?

how to tell if miso soup is bad

There are various ways to tell if your miso soup has gone bad and they include;.

  • If the miso soup has a fishy, rotten smell. This is mainly caused by bacterial contamination when it has been left out for a long time and it is advised to discard it immediately. .
  • If the soup has a sour and slightly bitter taste with a white film covering floating on top. This is also due to bacterial contamination and excess fermentation.
  • If the colour of the broth is dark and cloudy and the soup has a lumpy or grainy texture. This is caused by letting it sit out and be exposed to air for too long.
  • If the soup appears crystallized around the edges, discard it immediately because it has spoiled. This mainly occurs when it has been left out at room temperature for an extended period.
  • If the miso soup becomes too thick, do not consume it as it has gone bad. Leaving it out in the open for long may promote bacterial contamination thus changing its consistency. .
  • If the soup is discoloured, this is a sign of spoilage due to bacterial infestation.

Although miso soup might change its colour when stored, it shouldn’t be drastic.

Also, it should never change its flavour – it might lose the initial “punch” but it should never have a different taste from what it had initially.

Once you discover your miso soup has one of the signs above, do not consume it as you’ll be risking having food poisoning.


Miso soup is an easy-to-prepare Japanese broth traditionally made of tofu, miso paste, spring onions, wakame and dashi and it can last between 2-3 days if refrigerated and up to 2 months if frozen.

If left out, it can last for just a couple of hours.

Microbial infestation is the major reason why this soup goes bad that’s why storing it properly, in well-sealed containers, is the key to prolonging its shelf life.

To ensure you have good miso soup, refrain from leaving it open at room temperature.

You can also freeze it to keep it good for longer.

How Long Does Miso Soup Last? Does Miso Soup Go Bad?

Recipe by Andrew Gray Course: Shelf Life


Prep time


Cooking time


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  • Miso soup

  • Air-tight containers or Ziplock bags

  • Labels and markers


  • Miso soup Shelf life:
  • In fridge: can last between 2 and 3 days.
  • In pantry: only last for several hours, between 2 and 6 hours.
  • In freezer: last for about 2 to 3 months.

Recipe Video


  • Make sure to label your container with the content and date.
  • Store the container in a cool, dark place, like a pantry or fridge.
  • If you freeze the product, thaw it in the fridge before using. Always check for signs of spoilage before using.

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