How Long Does Natto Last in Fridge?

Last Updated on August 31, 2023 by Lauren Beck

Ah, the age-old question: How long does natto truly last in the fridge? As a fervent explorer of all things culinary, I’ve danced with fermented fare aplenty. 

Today, let’s unravel the mysteries of natto’s shelf life – a journey that requires little more than curiosity and a trusty refrigerator.

How Long Does Natto Last in the Fridge?

The suspense ends here! When stored properly in the fridge, natto lasts about 1 to 2 weeks. 

However, this is just a general estimate – your natto’s fate might vary depending on packaging, freshness at purchase, and your fridge’s overall temperature consistency. 

So, while it may not be a marathon runner in terms of longevity, Natto still knows how to keep its cool for a reasonable amount of time.

How to Store Natto in the Fridge?

Storing natto isn’t rocket science, but a little know-how doesn’t hurt. To keep those slimy, fermented beans happy, follow these steps:

  • Keep natto in its original packaging or airtight container to prevent it from drying out.
  • Place it in the fridge’s coldest area, usually the back, away from temperature fluctuations caused by frequent opening.
  • Ensure your fridge temperature is around 36 to 39°F (2 to 4°C) for optimal preservation.

Signs of Spoiled Natto

Sadly, even the coolest of dishes can meet their match. Here’s how to spot the signs of natto that has seen better days:

  • Off-putting odor: If it smells anything beyond its usual “unique,” it’s time to bid adieu.
  • Odd texture: If the texture becomes excessively slimy, gooey, or dry, it might be past its prime.
  • Unappetizing color changes: Look out for discoloration or any unusual growth on the beans.

Can You Freeze Natto for Longer Storage?

Homemade Natto

Absolutely! Freezing natto is like putting it in suspended animation. Simply place it in an airtight container, ensuring you’ve removed excess air, and pop it in the freezer. 

The texture may change slightly, but its flavor and nutritional value should remain intact. When thawed, use it within a week for the best taste experience.

How to Handle Thawed Natto?

Thawing frozen natto isn’t tricky, either. Move it from the freezer to the fridge and let it thaw slowly. Remember, abrupt temperature changes can lead to unwanted texture shifts.

Does Natto Spoil Without Refrigeration?

Yes, Natto [1] isn’t a fan of warm, unregulated environments. Without the cool embrace of a refrigerator, natto can go bad quickly, turning into a playground for not-so-friendly microorganisms. So, keep it chilled to avoid a slimy disaster.

What Temperature Can Kill Natto?

Natto’s resilience isn’t boundless. Exposure to high temperatures, particularly above 140°F (60°C), can end its lively bacterial activity. So, forget about trying to bake it into a bread topping – it won’t survive the heat.

Can You Save Natto for Later?

Absolutely! If you have leftover natto after cracking open a pack, just remember to store it properly in an airtight container and return it to the fridge ASAP. 

Its remaining shelf life will be shorter than the original, so aim to consume it within a few days.

Can I Eat Expired Natto?

While natto doesn’t have an “expiration date” per se, consuming natto well past its prime is like inviting trouble to dinner. Trust your senses – if it looks, smells, or tastes off, it’s best to bid it farewell.


In the realm of kitchen wisdom, understanding natto’s fridge life is a gentle art. Through my culinary escapades, I’ve found that while natto might not hold an eternal embrace with our refrigerators, a bit of care goes a long way. 

Embrace freshness, master the art of proper storage, and indulge in this fermented wonder at its prime. 

So, fellow food enthusiasts, remember: a dash of knowledge, a sprinkle of respect, and your natto will reward you with a unique and delightful flavor journey.


Lauren Beck
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