How to Store Onigiri (Omusubi) and How Long does it Last

Onigiri is a Japanese dish consisting of a rice ball (although traditionally it is usually given a triangular shape) filled with something salty and a nori wrap. Now I’m pretty sure if you cooked or bought them, you have wondered, How do I store onigiri? Summarizing:

Depending on the filling type, the onigiri can last from 2 to 12 hours at room temperature. If you use an airtight container, you can extend its shelf life in the fridge for 3 to 5 days. Finally, and depending the filling, you can store onigiri in the freezer for 3 to 6 months.

Store Onigiri

To know how to conserve onigiri properly, just read on.

Can onigiri be stored at room temperature?

Onigiri is a dish that in Japan is usually prepared to put in Bentos, that is, to store in a lunch box and eat later.

However, depending on the type of onigiri and the filling, it can withstand more or less time at room temperature.

For example, onigiris with salty filling and well-cooked usually last 6 to 12 hours at room temperature.

On the other hand, those onigiris with mayo filling or raw fish can only be kept at most for about 2 hours at room temperature, so as you can see, Onigiri needs to be refrigerated.

So, if you want to eat it for a picnic or take it as a slice for work, use containers that keep food well.

How to store onigiri in the fridge

Storing in the fridge is one of the two methods you can use to preserve onigiri correctly.

  • Step 1: Remove the nori and wait for the onigiri to cool.

If you do not plan to eat the onigiri soon, I advise you to remove the nori layer and keep it apart.

In addition, when assembling the onigiri, the rice is usually warm as it is more manageable, so wait for it to cool completely before storing it.

  • Step 2: Wrap the onigiri.

Wrap the onigiri on both sides with plastic film to prevent the rice from getting hard and dry from the cold.

  • Step 3: Put the onigiri inside an airtight bag or container.

To prevent onigiri from absorbing other foods’ flavors and the cold from hardening the rice, put it inside an airtight container or bag, acting as a second layer of protection. 

  • Step 4: Store the onigiri in the fridge.

Put the container or bag in the coldest area of your refrigerator (bottom), so you can keep the onigiri with salty filling well cooked for 3 to 5 days.

While the onigiri with mayo filling or some uncooked product can only be refrigerated for 24 hours

How to freeze onigiri

You can freeze the onigiri, but you must find out if the filling that has you can freeze well or not. For example, if the onigiri has mayonnaise in the filling, avoid freezing it.

To freeze the onigiri, you have to follow these indications that I leave you:

  • Step 1: Remove the nori and wait for the onigiri to cool.

Removing the nori before storing it is even more essential since it could get damaged when thawed. In addition, it is also advisable to wait for the onigiri to be cold before wrapping it.

  • Step 2: Prepare double wrapping.

First, put a layer of plastic film and another aluminum foil, or you can also place two layers of wraparound plastic to protect the onigiri from freezing burns.

  • Step 3: Place the onigiri inside a bag or container suitable for freezing.

This way, you add an extra layer of protection to the onigiri.

  • Step 4: Tag.

Write the product’s name on the bag and place the date of storage, or stick a label on the container with that information.

  • Step 6: Save the onigiri in the freezer.

You may freeze the onigiri for an estimated period of 3 to 6 months. However, I should note that the more time you spend stored in the freezer, you run the risk of losing consistency (the rice could harden a lot) and flavor.


How to keep onigiri fresh?

The best way to keep the onigiri fresh is to wrap it and save it in an airtight container as these layers of protection will help against oxidation.

Can you eat onigiri the next day?

If you store onigiri in the fridge or freezer, you indeed can to eat it the next day, regardless the filling or stuffing you use to make it.

Can you freeze Onigiri?

You can freeze for up to 6 months if the filling you use to make them is able to be stored in the freezer. For example, if the onigiri has mayonnaise, you can not store it in the freezer. Keep in mind that it will lose its quality as the freezer will dries out the rice.

How do you know if the onigiri is in poor condition?

If the onigiri has mold, it is in poor condition. So if you notice that it has some black spots or green bears, it will have already been filled with bacteria and completely contaminated, so you should throw it in the trash.

It is also bad if the onigiri has a foul smell or taste, such as rancid or sour. In that case, you should also discard it to avoid any intoxication.

Another sign that the onigiri has broken down is whether it has broken down and is highly watered down. Although onigiri with dry or hard rice does not imply that it is terrible, it is not very pleasant to eat.

Why is the onigiri spoiled?

The main reason why onigiri spoils is due to its fillings and other additions.

In addition, rice can absorb a lot of moisture, which, if it does not have good storage, could be a perfect breeding ground for microorganisms that can be harmful to the body.

Also, rice can absorb the smell of other foods and modifies its flavor, although it does not harm it. And in dry and hot environments, the moisture in the rice could dry out and end up disrupting the onigiri.

How long does onigiri last outside the fridge?

Onigiri lasts 2 to 4 hours at room temperature if you add raw or dairy products to its preparation. On the other hand, if you do not use raw meat or mayo, it can last 12 hours or maybe 1 day if you wrap it in plastic film.

How long does onigiri last in the fridge?

Onigiri without raw and dairy products last in the fridge from 3 to 5 days if you wrap it with plastic film and keep it in an airtight container. Otherwise, if you make the onigiri with tuna, salmon or mayo, you better consume it within 24 hours if you keep it in the fridge.

How long does onigiri last in the freezer?

Onigiri lasts from 3 to 6 months in the freezer if you double wrap and keep it in an airtight container. However, if you added mayo in its preparation, you should not store the onigiri in the freezer.

The following table summarizes “how long does onigiri last” in any case:

Onigiri at room temperature (without mayonnaise or raw food)6 – 12 hours
Onigiri at room temperature (stuffed with mayonnaise or raw food)2 hours
Onigiri in the fridge (without mayonnaise or raw food)3 – 5 days
Onigiri in the fridge (stuffed with mayonnaise or raw food)24 hours
Onigiri frozen3 – 6 months

What is the best way to store onigiri?

One of the best ways to preserve onigiri is to store it in the fridge to keep it in good condition, consistency, and taste.

You can also freeze the onigiri; however, the longer it is in the freezer, it will lose flavor, apart from the fact that it can harden the rice a lot if it is not stored correctly.

It is not advisable to leave the onigiri at room temperature beyond the recommended hours.

I invite you to keep reading all the content I have about food storage. The following posts may be super helpful to you.

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