How Long Does Miso Paste Last? Does It Go Bad?

If you enjoy experimenting with more exotic cuisines and want to prepare an authentic Japanese dish, you will probably need miso paste. Thankfully it is readily available on the market.

The problem is that it is often sold in non-resealable plastic bags. But even if you have miso paste in a jar or a box, you may be questioning what the best way to store it is and how long does miso paste last.

Here is some basic information about the shelf-life of miso paste. We have included tips for storing it and how to tell if it has gone bad.

What is Miso Paste’s Shelf Life?


While some brands of miso paste come with best-by dates printed on their packages, others don’t. This depends on where it was made and the local regulations requiring the inclusion of such information.

If you have bought miso paste that has a best-by date, you can expect it to be at its peak quality up to that date. When the miso is not opened and is stored correctly, you can be pretty certain that it will be at its best quality even several months after the best-by date.

If your miso paste only has a production date on the jar or package, then you can assume that it will last for at least a year.

Miso has such a long shelf life because it is a fermented product with a lot of added salt, which acts as a preservative. The miso will continue to ferment very slowly over time, but it won’t go bad. If left unused for too long, it may start losing some of its sweetness and taste.

Once you open the jar or the package, the degradation of the quality will intensify. Your open miso paste should last and retain its peak quality for up to 3 months. After that, the changes in the taste and texture may become more noticeable. Still, it will remain safe to use and consume.

Related: 10 Best Miso Pastes for Miso Soup, Stir Fries, or Meat Marinades

How to Determine that the Miso Has Gone Bad?

As mentioned above, miso paste has a very long shelf life, and the likelihood of it going bad is minimal.

Still, if you notice any signs of spoilage, such as an off smell, changes in color, or mold, you should dispose of the paste immediately.

If you are unsure whether it is no longer good for consumption, you can taste a small bit and decide whether it is time to throw it out.

While it will not spoil, miso will gradually start losing its flavors, so once you notice that it is no longer as palatable as you want it to be, it is time to throw it out and buy a new batch.

What is the Proper Way for Storing Miso?


Unopened jars, tubs, or packages of miso paste should be stored in a cool, dry, and dark place like a cabinet or pantry.

Keep it away from any direct light or heat sources such as a window or oven. Also, make sure that it is not exposed to big fluctuations in the temperature.

Once the miso paste is opened, it is best to move it to a mason jar or an airtight container. Always ensure that you seal it tightly after use.

While it is better to store the opened miso in the fridge, some manufacturers suggest it can be kept in the pantry in cool and dark conditions.

Read the instructions provided by the manufacturer, and if there aren’t any, then it is better to store the open miso in the fridge.

To keep the miso paste at its best quality, always use a clean spoon or another utensil when you are scooping out some of it from its jar or container. This will help reduce the risk of bacterial cross-contamination.

But given that the miso is a fermented product with lots of salt, the chances of microbial contamination are very slim.

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