Onigiri: How To Make Japanese Onigiri Rice Balls

Onigiri has different names like o-musubi, nigirimeshi, and, simply, rice ball. It is a type of Japanese food made of white rice that is shaped in triangular or cylindrical forms and sometimes wrapped in nori. As a natural preservative, an onigiri is usually filled with pickled ume (umeboshi), salted salmon, katsuobushi, kombu, tarako, or some other salty or sour ingredient. 

Most convenience stores in Japan stock their onigiri with various fillings and flavors. There are also specialist shops that sell only onigiri to carry away. Onigiri has become a common staple in Japanese restaurants worldwide.

Contrary to common misunderstandings, onigiri is not a sushi form, and should not be confused with the sushi type called nigirizushi or nigiri. Onigiri is made from plain rice (sometimes lightly salted), while sushi consists of vinegar, sugar and salt rice. Onigiri makes rice compact and easy to eat and store, while sushi has emerged as a way to serve fish.

Japanese Onigiri Rice Balls

  • Author: Romae Chanice Marquez
  • Recipe Category: Snacks
  • Cuisine: Japanese

Japanese rice balls are the healthiest option between meals for a fast snack. They can also be mixed with soup and other products for an easy and satisfying meal. There is a rice ball out there for everyone, with a wide range of onigiri fillings available.

The whole preparation and cooking time is for 1 hour. This recipe is suitable to create 12 onigiris. 

Photo credit:pickledplum.com

Japanese Onigiri Rice Balls Ingredients

  • 3 cups uncooked Japanese short-grain rice
  • 2 ½ cups water
  • kosher/sea salt 
  • 5 sheets nori (seaweed)
  • Salted salmon (recipe follows)
    • 1 salmon fillet
  • Okaka (recipe follows)
    • 3 packages Katsuobushi (dried bonito flakes)
    • Tbsp soy sauce
  • 4 umeboshi (Japanese pickled plum)
  • seasoned kombu
  • Toasted white and black sesame seeds(to garnish)
  • kosher/sea salt (use half for table salt)

For Tuna Mayo,

  • 1 canned tuna
  • 3 Tbsp Japanese mayonnaise
  • ½ Tbsp soy sauce

Japanese Onigiri Rice Balls Instructions

Step 1: For the rice  Place the rice in a wide bowl and wash the rice gently in a circular motion, then remove the water. Repeat about 3-4 times on this cycle. Let the rice soak in water for 30 minutes. Switch the rice to a sieve and drain, for at least 15 minutes. In a heavy-bottom dish, mix the rice with water for cooking.

Step 2: Cover the lid and over medium heat, bring to a boil. Turn the heat to the lowest setting once water is boiling and continue cooking covered for 12 to 13 minutes. Take a look at 12-13 minute mark and if you see any water left, close the lid and let it work for another minute or so.

Step 3: Remove the pot from the heat (with the lid on) and allow to steam for another 10 minutes. Then switch the rice over to a large plate. Fluff the rice with a scooper on the plate. Let the cooked rice cool down a bit so the rice can be held without burning your hands. Do not let the rice cool down completely, though.

Step 4: For the FillingThe onigiri fillings are prepared when rice is soaked and drained.

Salted salmon filling: Brush both sides of the salmon filet with kosher salt. Bake in a toaster oven or microwave for 25 minutes, at 400F (200C). Break the salmon into flakes, and set aside.

Umeboshi filling: Place the umeboshi (Japanese pickled plums) on a plastic wrap sheet that is 10″x 10″. Fold in half, and squeeze every umeboshi seed out. Dispose of the seeds and hold flesh in the umeboshi.

Okaka filling: In a cup, put katsuobushi (dried bonito flakes) and add 2 tbsp of soy sauce. Combine to blend. Katsuobushi should be moist, and there should be no soy sauce left at the bowl’s bottom.

Seasoned kombu filling: Place the seasoned kombu that you purchased into a bowl for easy later exposure.

Step 5: Tuna Mayo — Place canned tuna drained in a bowl and add 2 tbsp of Japanese mayonnaise and 1⁄2 tbsp of soy sauce. Combine to blend.

Step 6: For the Onigiri — Split the sheets of nori into thirds. Next, spray both of your hands with water to prevent the rice from sticking to your palms. Put some salt in your hands then rub it around your palms.

Dip three tips of your fingers into kosher salt. Use half the amount when using table salt because it is saltier than kosher salt. Scoop out a handful of warm rice into one hand (about 1/3 cup).

Make a tiny hole in the rice’s core. Place one form of filling inside (approx. 1-2 tsp.) Then mold the rice around the hole with your hands to fully cover your filling.

Wrap the nori (seaweed) onigiri over the rice. Place a bit of each filling on top of onigiri so you know what kind of filling is inside.

Japanese Onigiri Rice Balls Additional Information

  • Onigiri, at its most simple form, is a ball of steaming hot Japanese rice that is salted and either formed by hand or made with an onigiri press to form a triangle, circle or cylinder shape. There are countless kinds of onigiri and ways of producing it.
  • This recipe will take 1 hour to make. 
  • This recipe will make enough for 12 onigiris.

Image source: loveandoliveoil.com

About Japanese Onigiri Rice Balls Recipe

The use of a hole to fill the onigiri made it easier to create new onigiri flavors as this cooking process did not require ingredient-to-ingredient changes. Traditional mechanically wrapped onigiri are specially folded in such a way that the plastic covering between nori and rice serves as a shield against moisture. When both ends of the package are pulled open, the nori and rice come into contact.


A device was invented in the 1980s that rendered triangular onigiri. Instead of rolling the filling inside, the flavoring in the onigiri was placed into a cavity, and nori covered the opening. Since the onigiri made from this machine came with nori already added to the rice ball, the nori became moist, sticking to the rice over time. For more international recipes, click here.

Featured Image: Image 1,  Image 2