Can Miso Expire? Storage tips & how to tell when it goes bad

                by Joost Nusselder | Updated:  May 30, 2021

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Ever had trouble finding Japanese recipes that were easy to make?

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If you’ve bought miso for a recipe, then

  1. you probably loved that recipe, but
  2. chances are you have a lot leftover in the container

It might even be a while before you can finish the whole thing as most recipes only require a tablespoon or two.

Can it expire? And how can you best store it? Yes, that’s what we’ll look at here.

Can miso expire

An unopened can of miso will not likely expire because the fermentation process will keep going but at some point the quality may gradually degrade. Opened miso may also unlikely expire if stored properly. The more you open the jar, the more prone it is to contamination and quality degradation.

Eventually, you might need to throw it away.

How Long Can Miso Last?

Miso can last long because it will keep on fermenting as long as the package is still sealed.

It does not even need chemical preservatives. Once you open it, miso will start degrading its quality and taste.

An unopened jar of miso can last about a year before starting to degrade. Most companies may put the “best before” label on the package to notify the estimated time when the miso would likely start degrading.

However, most of the time, miso would still be safe to consume even a few months after the date.

An opened miso is quicker to degrade, especially if the jar is opened too often or not properly sealed.

There is a chance the miso will get bacteria contamination that makes it get mold or smells bad.

In general, you only have three months to keep the miso once you open the package.

How do I best store Miso?

If you haven’t opened the miso jar, it can stay in a cold room temperature.

So, a kitchen cabinet is still fine. Avoid placing it near the stove or oven because heat will heavily affect its quality.

After you open the jar, the miso will start degrading. Move it into the fridge to slow down the process.

Make sure to close it well because even a little bit of air will affect the miso. Use a clean and dry spoon every time you scoop out the miso paste to avoid contamination.

Also read: do this if you want to freeze your miso

How Miso Turns Bad

Once opened, miso will gradually lower its quality in terms of taste and smell. It is still normal and safe as long as there are no subtle differences in it.

However, if your miso has developed discoloration, it is best to throw it away.

When reopening your miso jar, see if it looks different than it should look. You can give it a little sniff to make sure it still smells fine before you use it for cooking.

If you are still unsure, you can scoop a tiny bit of it and try tasting it.

Miso has a low chance of expiring. But that doesn’t mean you can be reckless about it.

If you are not sure you can finish the miso in three months after opening it, you might better buy the smaller package. But while you have it, be sure to store it properly.

Can miso soup expire?

Miso soup is a common side dish in most Japanese cuisines. Famous for its umami flavors, many home cooks have since learned to make their own miso soups to use as broths or to serve as a side dish.

In fact, did you know that instead of cooking them in small batches, many chefs have opted to make them in large batches to store?

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Favorite Asian Recipes

But you may also wonder at this point – can miso soup go bad?

Can miso soup go bad

Miso soup doesn’t expire as quickly as you think. When stored in an airtight container and left in the fridge, miso soups are generally safe to consume for the next 3 days. Of course, you’ll have to reheat it before drinking or to use it as a soup base, and it’s always best if there are no condiments like seaweed or tofu in your soup.

Can you freeze miso soup?

If you’re looking to store miso soup for an even longer period, you could always place them in a freezer-safe bag or airtight container to freeze them for up to 6 months.

Miso soups are also good when portioned into ice cube trays, so you wouldn’t have to thaw the entire batch of soup when you want to use it.

Also read: this is how you freeze miso soup as well as miso paste

So, how can you tell when your miso soup has gone bad? Because miso soups have a natural umami flavor, it can be hard to tell when your soup has gone bad.

As a rule of thumb, you should throw out any refrigerated miso soup after 3 days – regardless if it has condiments or not.

Separately, it would also be good to date any frozen miso soups, so you’ll know how long it has been kept in your freezer.

It’s not recommended to use any miso soups that have been frozen for over 6 months, or if it’s visibly discolored upon thawing.

When your miso soup looks more cloudy than usual or has mold on them, those would also be clear signs that it’s time to throw it out.

Finally, miso soups that have been left out overnight without being kept in the refrigerator should never be consumed as it’s difficult to tell if it has gone bad.

This is especially true for any miso soups that may have added condiments like tofu and seaweed or other seafood products.

Miso soups that have gone bad would also emit an unpleasant fishy smell, and that’s when you know it’s not safe for consumption anymore.

Also read: this is how you make a nice miso soup breakfast

Also, you can check out these miso substitutes if you don’t have it (or just had to throw it away after reading this).

Ever had trouble finding Japanese recipes that were easy to make?

We now have "cooking Japanese with ease", our full recipe book and video course with step-by-step tutorials on your favorite recipes.

Joost Nusselder, the founder of Bite My Bun is a content marketer, dad and loves trying out new food with Japanese food at the heart of his passion, and together with his team he's been creating in-depth blog articles since 2016 to help loyal readers with recipes and cooking tips.