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Preserving the Flavors: How Long Does Onigiri Last?

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Onigiri, or rice balls, are a traditional Japanese food made from white rice formed into triangular or cylindrical shapes and usually wrapped in nori (seaweed).

They can be filled with anything from jam to meat.

This article will cover how long onigiri lasts, how to store it, and how to prepare it for eating.

What is Onigiri?

what is onigiri

Onigiri is the Japanese word for “rice ball”.

It’s a popular food in Japan, as well as many other Asian countries.

Onigiris are often given out during traditional rituals or festivals and can be made from various ingredients such as salt-pickles (called tsukemono) or fish paste (called ikura).

The origin of onigiri is rooted in history.

In the Kamakura period, to cope with limited cooking supplies and lack of space for storage, cooks made “rice balls” that were simply flavored with salt as an easy meal option.

It wasn’t until late into the Edo era when nori became more popularized due to farmers cultivating it extensively, which allowed them to make sheets out from this new ingredient- making it suitable for wrapping around rice.

You can find these flavorsome snacks today at convenience stores everywhere.

Onigiri can be consumed with a dipping sauce (usually soy sauce) or just wetted by the hands from water.

With a wide variety of types of onigiri and fillings, there’s an onigiri out there for everyone.

Types of Onigiri

types of onigiri

One thing that is unique about onigiri, and Japanese food in general, is the variety of different regional styles.

There are five main types of onigiri:

  • Wrapped onigiri – these are shaped like a triangle or rectangle that wraps around something filling; they can be made with nori seaweed to form a pocket for holding fillings.
  • Seasoned onigiri – rice balls topped with soy sauce or other sauces such as teriyaki or mayonnaise.
  • Yaki-Onigiri – grilled versions of seasoned onigiris which tend to have some sort of meat topping (options include bacon bits, unagi eel).
  • Mixed Rice Onigirazu – this type has mixed ingredients, including vegetables, meat, and even fruit.
  • Onigirazu – these are like a rice sandwich with fillings such as tuna mayonnaise or eel; they can also be made with fried eggs to make egg onigiri.

Each type of onigiri is accompanied by unique flavors and textures, so the next time you’re looking for some delicious Japanese food to eat at home or take with you when traveling, try a different type of onigiri.

How to Make Onigiri?

how to make onigiri

Onigiri is a popular food in many Asian countries, but it has grown to be very popular worldwide as well.

It’s typically made using cooked rice and combining with some kind of filling such as ikura (salmon roe), avocado, or cucumber.

It can be made by hand with an onigiri mold shaped like the traditional triangle shape that is popular in Japan.

It also can be formed into balls and then filled with various kinds of ingredients before it is molded to make an easier shape.

To make onigiri by hand, you will need:

  • Cooked rice.
  • Vinegar or sugar.
  • salt and/or wasabi to the season with.
  • Fillings of choice.


  • Place cooked rice in a bowl and season according to preference. Form small portions using fingertips before rolling into balls, then filling and shape accordingly.
  • Place cut vegetable fillings inside of each ball-shaped piece of sushi rice for an easy way to form them without having to go through all the hassle.
  • It is also good if you are trying to avoid eating raw fish products such as salmon roe (ikura), which some people may not want to eat.

How to Store Onigiri?

how to store onigiri

The word onigiri translates to “rice in the shape of a ball” from ancient Japanese.

While onigiri was originally developed as food for traveling people, it has evolved into a popular lunch dish in Japan.

Onigiris can be eaten plain or with soy sauce and vinegar.

They are also often wrapped with nori (seaweed) before being served.

The rice is the key component of an onigiri which makes them delicate to store because they soften easily when exposed to temperature and humidity changes from day-to-day living conditions.

As such, you need to think about how long your meal will last and select a storage container that’s appropriate for what you have made:

  • For rice that will travel with you for a day or two, a container like Tupperware is best. It keeps the food from spilling out and protects it from losing moisture due to condensation.
  • If you need a container large enough to store many onigiris at once (such as in an office pantry), choose plastic containers because they are inexpensive, durable, and not likely to break even if they get knocked around during transport.
  • Airtight glass jars are great for home use; however, these can be heavy, so lugging them around is not always practical.
  • For long-term storage, plastic bags are the best option because they’re lightweight and can be sealed tightly to keep out insects or moisture.
  • Whatever container you choose for storing onigiri, make sure that it has a tight seal, so your rice doesn’t dry up.
  • Ideally, store in the fridge where temperatures are stable at about 40 degrees Fahrenheit (-40deg C), but if this is not an option, then don’t worry: just pop them into the freezer instead – as long as they’re wrapped well enough to avoid freezer burn. If freshness isn’t of utmost importance, freezing will do just fine.

How Long Does Onigiri Last?

how long does onigiri last

There is a variety of onigiri: rice balls with tuna or other fillings.

The shelf life varies depending on the filling and what it’s made of, so take care in deciding which type you want to eat.

Just remember that rice is perishable, but many people love onigiri for its simplicity as well as being served widely throughout Japan.

And they’re delicious too.

Might it be better not to store them for more than one day tops, though? Or, if you do keep it in your fridge, make sure to cover it with plastic wrap or put it inside an airtight container before storing it.

If your onigiris are made with umeboshi, you can keep them in your fridge for up to three days.

If the onigiris contain tuna and mayonnaise, they can last for up to one day.

In general, any filling with mayo is usually not good for more than a day.

If you want to save your onigiri for later, it’s best to freeze them.

Simply place the wrapped rice balls in a plastic bag and put them into the freezer.

The ones with tuna mayonnaise should be eaten within one day, while those without this filling can last up to two weeks.

Let your frozen onigiri thaw overnight before enjoying.

The dates are different depending on what kind of fillings they have, so make sure that if you’re storing any food items in your fridge or freezer that you know how long each type lasts before eating them again.

It’s easy enough to make them fresh every day or every other day if you want your onigiri looking fresh and tasty all the time.

So enjoy.

How to Tell if Onigiri is Bad?

how to tell if onigiri is bad

Like most foods, onigiri can go bad.

And while it may seem obvious that rice will spoil after a certain amount of time, the same goes for other ingredients in onigiri too.

Here are some signs to look out for and what you should do if they occur:

Sour: Sour onigiri is the result of improper fermentation.

Once it’s sour, there isn’t much you can do to save it.

You should discard this type of bad onigiri immediately and make a fresh batch.

Moldy Onigiri: Moldy rice is caused by improperly cooked rice or too many hours without refrigeration.

To prevent mold from growing in your rice, cook the grains completely each time before packing them into an airtight container if they aren’t going to be eaten within two days.

Musty: Mustiness usually occurs because something spilled inside the package while it was being stored (usually soy sauce).

Discard any musty packages as soon as possible – even though some may still taste good, the mustiness will eventually ruin any onigiri.

Stale: Stale rice is usually caused by long periods of storage without refrigeration and lack of moisture.

One way to prevent this is to make sure you store your onigiri in a tightly sealed container with plenty of room for air circulation at all times.

Rancid: Rancidity occurs when food starts oxidizing and turning into something more like oil than what it was originally meant to be – not so appetizing, right?

To avoid rancid onigiri, always try to eat them within two days or put them in an airtight container before storing them in the fridge if they won’t be eaten within that time frame.


The onigiri is a type of Japanese food made from rice that has been shaped into triangular or cylindrical shapes.

It’s typically wrapped in nori and then filled with fish, vegetables, meat, or other ingredients.

The best way to eat onigiri is right after it’s been made because the rice will be soft and flavorful.

If you have leftovers, though, store them in an airtight container at room temperature for up to 3 days (much like sushi).

You can also freeze leftover onigiri for up to 2 weeks by wrapping it tightly with plastic wrap before placing it inside a freezer bag.

How Long Does Onigiri Last? Does Onigiri Go Bad?

Recipe by Kimberly Baxter Course: Shelf Life


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  • Onigiri

  • Air-tight containers or Ziplock bags

  • Labels and markers


  • Read the guide thoroughly to learn how long it lasts.
  • Label your container with the content and date and keep track of how much you're using!
  • Make sure to store in an airtight container in a cool, dark place (pantry or fridge).

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