How Long Does Miso Paste Last? 4 Signs To Tell It Was Bad

You’ve chosen to branch out into Japanese food and try miso soup, one of the country’s most popular dishes. Undoubtedly, you’ve purchased a jar of miso paste, as well as a variety of other components such as tofu or seaweed.

After preparing the soup, you begin to wonder about the miso shelf life. You just use a few teaspoons each time, and you don’t cook that dish on a regular basis. So, you estimate that it will take you a few months to finish the jar, and a question pops up in your mind – how long does miso paste last?

For a precise answer, read on!

What Is Miso?

How Long Does Miso Paste Last
Miso Paste

Soybean paste, or miso, is prepared from fermented soybeans. Soybeans are combined with koji and salt, a mold used in the production of sake. Rye, rice, arley, and other grains may be included in the mix.

The combination ferments for several months to years to achieve its distinctive taste. As a result, the miso paste darkens and becomes richer in taste as it ages.

A tablespoon of this popular Japanese condiment can infuse tofu or ramen with substantial flavor. Miso not only adds a savory flavor to your cuisine, but it’s also excellent for you. Miso paste comprises probiotics, good bacteria that may help increase your immune system, create a healthier gut, and relieve some of the levels of psychological distress because it is a fermented condiment.

How Long Does Miso Paste Last

Miso may be stored for a long time because it will continue to ferment as long as the container is unopened. Unopened jars of miso can remain for up to a year before degrading. Meanwhile, after you open the package of miso, you only have 3 months to store it.

Chemical preservatives aren’t even required. However, the quality and flavor of it will begin to deteriorate as soon as it is opened. Most businesses will place a “best before” marking on the packaging to indicate when the miso is expected to start degrading.

A miso jar that has been opened is more likely to decay, especially if it has been opened too many times or is not well packed.

There’s a possibility the miso will become contaminated with germs, resulting in mold or an unpleasant odor.

Storage ConditionsRoom Temperature (Cool, dry place)  Fridge
Unopened Packaging Miso Pasteup to 1 yearup to 1 year
Opened Miso Paste3 monthsMore than 3 months and up to 1 year.

Please keep in mind that the times listed above are just for the finest quality. Miso that is appropriately preserved will keep its quality for a long time.

How To Tell If Miso Paste is Bad

It’s hard to see the difference between bad and good miso because you’re already eating fermented paste! Yet, there are signs that reveal to you the state of this food – smell, discolorations, and mold.

  1. Your initial instinct, though, should be to believe your sense of smell. If the miso has an unpleasant odor or doesn’t odor like the miso you know, throw it out right away.
  2. Bad miso would have some discoloration or the look of mold.
  3. Food molds, on the other hand, are untrustworthy, and it’s almost certain that the miso has gone rogue and deserves to be thrown out.
  4. Miso can darken in color, but it is still edible unless it has an unpleasant odor or mold development.

As mentioned above, spoiling or not depends on the number of times you open it and the storage time.

Although miso paste is unlikely to spoil and can even last for years due to its ingredient, this does not mean that it will be completely safe from bacteria invasion. Make sure that you throw it away once you spot out any suspicious sign on it regarding smell and look.

How To Store Miso Paste

It’s perfectly safe to freeze miso paste, and it’s one of the only steps to prevent the taste from degrading over time. As miso is a paste, it can be frozen in a variety of ways to make it easier to utilize when you need it.
Here are a few tips when doing freezing miso storage to lengthen miso paste shelf life

  • You should freeze miso paste in an opaque plastic bag. This protects the miso paste from infection and allows it to be kept safely in a freezer bag that can be put flat to save room.
  • Storing miso paste on ice trays is a good way to go. This makes it easy to take the exact amount of miso you need every time without actually opening the entire refrigerated miso paste jar.
  • When frozen, miso paste retains its malleability. This permits you to freeze it in an airtight jar, then use a measuring spoon to take out as much as you need without needing to defrost the entire paste.
  • You can also store miso in smaller, individual containers and keep them all in the fridge at the same time. This eliminates the need to separate tiny batches of miso paste from a single container each time you need to use it. Besides, this also allows you to defrost the miso paste in one jar.

When miso paste is fermented, it has an extremely extended shelf life. It keeps for up to a year in an airtight jar in the fridge.

Because light miso will not last as long as darker miso, storing miso paste in a fridge is important, particularly if you seldom use it.

Homemade Miso Paste Recipe

Homemade Miso Paste Recipe
Homemade Miso Paste Recipe


  • 250g soybeans (or whatever grain, pulse, or seed you want)
  • 250 milliliters water
  • 125g dried rice koji
  • 18 grams of salt

Making Process

Step 1: Boil the soybeans first to generate a 7 percent sweet miso. The best approach here is steaming since they won’t gather excessively liquid. The drier the miso and the longer it lasts to ferment, the richer the flavor.

Step 2: In a mixer, blitz the boiled soybeans with the rest of the ingredients. You can combine until entirely smooth or retain some texture.

Move to a jar and tap it on the counter several times to remove unwanted trapped air — the carbon dioxide must exit, or the miso will develop unevenly.

Step 3: Wrap the jar with a muslin cloth and set it aside in a warm location; the hotter it is, the faster the procedure will go. If you don’t have a dehydrator, making miso requires about 5 days at 25°C.

Step 4: After 5 days, take a taste. If you like the flavor, keep it in the fridge to stop the fermentation, or start leaving it out for a couple of extra days to let it develop. Put the miso in the refrigerator to mature gradually if you’re not in a rush to use it.


Does Miso Need To Be Refrigerated?

Should miso be refrigerated? It’s best if you keep your miso paste chilled. You may extend the life of your food by keeping it this way, allowing you more time to eat up the leftovers.

However, there’s no need to keep unsealed miso paste refrigerated if it’s kept in an airtight jar. The miso paste, on the other hand, must be refrigerated as soon as the bottle is opened. When not using it, make sure the jar is firmly closed. From then on, store in the fridge because miso paste maintains its properties best in a freezing environment.

Can You Eat Miso Paste Raw?

Uncooked miso paste is perfectly edible, but it has a very powerful, salty, and full-bodied taste. Some individuals enjoy spreading miso paste on bread for the morning; however, this is a more specialized taste.

When cooked, miso paste constantly changes in flavor, but it retains the rich umami flavor that has made miso paste so prevalent. Miso paste can be eaten raw because it is made from fermented soybeans, and it is a wonderful source of probiotics as well as other minerals and vitamins.

Final Thoughts

So, how long does miso paste last? – This depends on some factors such as the time you store it, the state of the paste jar, and the storage temperature.

Miso is a common ingredient in Japanese cooking that adds savory and umami taste to dishes. It’s a long-lasting product that can be maintained on the shelf.

We suggest you store miso in the fridge after it has been opened. Producers, on the other hand, may have different storage recommendations. As a result, always read the label. The decline in the quality of Miso is a rare event.

Kevin Richard

Hi all! I’m Kevin. I spend plenty of time in the kitchen every day because I love cooking healthy and delicious foods for my family and friends. Cooking gives me a chance to be creative and fun. It’s also one of the most meaningful ways to express my love and take care of my little family.

Click Here to Leave a Comment Below 1 comments

Leave a Reply: