How long does onigiri last?

In this brief guide, we will answer the query, “How long does onigiri last?” and will discuss how to make onigiri.

How long does onigiri last?

The shelf life of onigiri depends upon the ingredients that are used in its processing. Umeboshi-based onigiris store well in the fridge for up to three days,  because of the antibacterial action of the citric acid on this pickled plum (1). For up to one day, onigiris with tuna and mayonnaise may be kept fresh. In general, mayonnaise-based fillings should be consumed within a day, when stored at temperatures lower than 13°C (1).

What exactly is Onigiri?

The Japanese word onigiri means “rice ball.” In Japan, as well as many other Asian countries, it is a popular dish. Onigiris are created from a variety of components such as salt-pickles (called tsukemono) or fish paste and are commonly given out during traditional rites or festivals (called ikura).

Onigiri has a long and illustrious history. To deal with limited cooking supplies and storage space during the Kamakura period, cooks developed “rice balls” that were simply seasoned with salt as an easy supper choice.

Farmers cultivating nori widely allowed them to manufacture sheets out of this new ingredient, making it perfect for wrapping around rice, and it wasn’t until late in the Edo era that nori became increasingly popular.

These tasty nibbles may now be found in convenience stores all around the country. Onigiri can be eaten with a dipping sauce (often soy sauce) or just dipped in water. There’s an onigiri for everyone with so many different types of onigiri and fillings.

Types of onigiri

The variety of regional variations of onigiri, and Japanese food in general, is one of its most distinguishing features. Onigiri is divided into five categories:

Wrapped onigiri – These are onigiri that are formed like a triangle or rectangle and wrap around a filling; they can be created with nori seaweed to provide a pocket for fillings.

Seasoned Onigiri – seasoned rice balls covered with soy sauce or other condiments like teriyaki or mayonnaise.

Yaki onigiri – Yaki Onigiri are grilled variants of seasoned onigiri, usually with a meat topping (options include bacon bits, unagi eel).

Mixed Rice Onigirazu – this type has a variety of components, such as vegetables, meat, and even fruit.   Onigirazu – Onigirazu is similar to a rice sandwich with contents like tuna mayonnaise or eel; egg onigiri can also be created with fried eggs.

Try a new sort of onigiri the next time you want some tasty Japanese food to consume at home or take with you when you travel.

How to make onigiri?

Onigiri is a famous dish in many Asian nations, but it has also gained popularity around the world. It’s often made with cooked rice and some sort of filler like ikura (salmon roe), avocado, or cucumber. It’s possible to make it by hand using an onigiri mold in the typical triangle shape common in Japan.

It can also be shaped into balls and then filled with various ingredients before being molded to achieve a more manageable shape. To make onigiri by hand, you’ll need the following ingredients:

  • Cooked rice
  • Vinegar or sugar
  • To season, use salt and/or wasabi.
  •  Fillings of your choice


·         In a mixing bowl, combine cooked rice and season to taste. Form small bits with your fingertips, then roll into balls, filling and shaping as needed.

 Fill each ball-shaped piece of sushi rice with sliced veggie fillings for a simple way to make them without having to go through all the trouble.

·         It’s particularly beneficial if you’re attempting to avoid raw fish products like salmon roe (ikura), which some people dislike.

What Is the Best Way to Store Onigiri?

In ancient Japanese, the word onigiri means “rice in the shape of a ball.” Onigiri was created as a snack for travelers, but it has since evolved into a famous lunch dish in Japan. Onigiris can be eaten simply or with vinegar and soy sauce. Before being served, they are frequently wrapped with nori (seaweed).

The rice is the most important component of an onigiri, making it difficult to keep because it softens easily when subjected to temperature and humidity variations in everyday living conditions. 

As a result, consider how long your dinner will last and choose a storage container that is appropriate for what you’ve prepared:

A container like Tupperware is ideal for rice that will be transported for a day or two. It prevents food from leaking out and prevents moisture loss due to humidity. 

If you need a container big enough to hold a lot of onigiris at once (like in an office pantry), go with plastic containers because they’re cheap, resilient, and won’t break even if they get banged around.

Airtight glass jars are ideal for use at home, but they can be hefty, making transporting them difficult. Plastic bags are the ideal alternative for long-term storage because they’re lightweight and can be sealed tightly to keep out insects and moisture. Usually, onigiris are stored at temperatures from 13°C to 20°C to maintain the characteristics of the cooked rice and not lose humidity. At this temperature, rice balls last one day (17 h to 55 h, depending on the ingredients) (1).

Make sure that any container you choose to store onigiri has a tight seal so that your rice doesn’t dry out. If you can’t store them in the fridge where temperatures are stable at around 40 degrees Fahrenheit (-40 degrees 4°C Celsius), don’t worry: just throw them in the freezer instead – as long as they’re wrapped well enough to avoid freezer burn. If freshness isn’t critical, freezing will suffice. onigiris can be stored for up to 6 months in the freezer (at temperatures of -18°C or under) (3).


In this brief guide, we answered the query, “How long does onigiri last?” and discussed how to make onigiri.


  1. Sato, Jun, and Kana Yokokawa. Evaluation of the adequacy of the consume-by date of rice balls sold at convenience stores. Biocontrol Sci, 2014, 19, 165-171
  2. Yeo, Seoungsoon, and Misook Kim. Predictive Growth Modeling of Listeria monocytogenes in Rice Balls and Its Risk Assessment. J Food Qual, 2020 (2020).
  3. Simpson, R., et al. Development of frozen sushi: optimization and shelf life simulation. J Food Process Preserv, 2008, 32, 681-696.