Want to know how to make onigiri rice balls with fillings? Learn step-by-step how to neatly stuff the fillings inside. Form them into a triangular shape and wrap them with seaweed— ta-da! Try out my fail-proof fusion fillings (salmon, avocado, mayo, shiso) or get creative with your own.
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My love story with Onigiri...
I can still remember the first time I discovered the onigiri section at a convenience store in Tokyo. It must have left a lasting impression on me because that was over 20 years ago.
At that time, I couldn't read a word of Japanese. I had to study the pictures on the triangular-shaped packages to guess what was inside. Sometimes it was a game of onigiri Russian roulette. "Tuna mayo" was a safe bet but I also wanted to explore.
Nowadays, I can't even remember the last time I bought an onigiri from a convenience store. I've become an onigiri connoisseur (snob).
My palate has evolved– homemade just taste so much better. And they don't contain preservatives like the ones that have to sit on a shelf.
Most of the time, I just order them at restaurants when I go out. But you don't need to live in Japan to eat onigiri. They're really not that time-consuming or difficult to make at home. It just takes some practice— you'll learn fast!
Table of Contents
Why You’ll Love These Onigiri with Fillings
I was just talking to my friend Caroline from pickledplum.com about this yesterday. We think it's fun to go to convenience stores in Japan because they're always creating something new and different.
As for onigiri, 7-11 is always going to have your traditional variety of fillings like umeboshi, tuna mayo, salted salmon, and marinated konbu (kelp). But they're also constantly reinventing the rice ball to make it new.
Don't get me wrong. Sometimes all I want is a salted onigiri with no fillings, plain and simple. But another thing I love about onigiri is the endless opportunities to invent new versions. You get to be creative!
I like to think of it as an upgrade, onigiri 2.0 + wasabi mayo.
If you need any help, just leave me a comment below! I personally respond to every message.
❤️ & 🍙 from Japan, Matt
Why Fusion Fillings?
Because I came to Japan as an outsider, I see Japanese food from a very different perspective. As a Japanese food blogger who is not Japanese, that's my edge. Intuitively, it only made sense that I should be the one who creates a new onigiri flavor.
It's fun to bite into a brand-new onigiri that you've never tried before. What's inside is an unexpected surprise. It's like being a kid again, digging for buried treasure hidden inside the rice.
My goal was to create a new onigiri filling combination that worked, 100%. You take that bite, get your first hit of wasabi mayo, and groan... ahhh, that's so good.
Onigiri in Japanese Culture
In Japan, I love how onigiri are seen as a symbol of kindness. The simple gesture of making homemade onigiri for a loved one shows that you care. Knowing this, you can understand why onigiri is considered a comfort food in Japan. An essential ingredient for making the most soul-satisfying onigiri is love. I just added some avocado.
Musubi in Modern Times
As convenience culture has taken over Japan, machine-made, store-bought onigiri have become the norm. If you go out during a lunch break in Tokyo, you'll see busy office workers grabbing them off the refrigerated shelves at konbini across Japan.
They're Japan's favorite portable snack. I see that tourists love them too!
According to Japan's Ministry of Agriculture, Forestry and Fisheries, 7-11 sells some 2 billion onigiri a year. While rice consumption has been on the decline, onigiri continue to be a mainstay in the Japanese diet. They're relatively healthy, inexpensive, and convenient.
Onigiri Shops in Tokyo
I live near Shinagawa Station, which has two onigiri shops inside. I just checked my Uber Eats app and found 11 shops that will deliver onigiri to my door. Onigiri Ishin in Gotanda, the one closest to me, has different sets to choose from. The most popular sets include two onigiri, karaage fried chicken, tamagoyaki, tonjiri, or simple miso soup.
In Tokyo, lately I've been noticing some new onigiri shops have been popping up.
In general, I find that there are two kinds of onigiri shops. The traditional onigiri shops which serve all the classics. These shops make their onigiri with rice that perfectly matches the fillings inside. They've already perfected their product over decades so why change a thing?
And then you have the other type, the innovators. These shops believe that there are infinite possibilities to recreate the onigiri. Probably thanks to Instagram, the humble onigiri has become a piece of art. Tesshi @tmytsm is an account that will definitely give you some inspiration.
Overseas, onigiri is not yet as popular as ramen and sushi. From what I've read, there are a few ambitious onigiri chains that dream of making onigiri the world's next fast food that's not unhealthy. Already chains have expanded overseas. Omusubi Gonbei has 51 chain stores in Japan, plus two stores in the United States and two in France.
Recipe at a Glance
Cuisine— Japanese Course— Breakfast, Lunch, Dinner, or Snack Dietary Info— Pescatarian, Paleo, Gluten-free Skill Level— Medium (requires some practice for novice cooks)
Ingredients
Japanese white rice: Sometimes called "sushi rice" outside of Japan. It's important that you use short-grain rice. In my easy onigiri recipe post, I go into detail about why I use Japanese white rice. You'll find also find my list of recommended brands.
Cold water: When making rice, the quality of water you cook your rice in matters. Use clean, filtered water whenever possible.
Nori seaweed sheets: Again, quality matters. The best sushi restaurants know this. You can buy full-size nori sheets and cut them into ⅓-sized strips. Or buy nori seaweed strips that are already the perfect size for wrapping onigiri.
Salt: I prefer to use sea salt or kosher salt that's fine grain, not coarse salt.
Fillings (& Topping)
Mayonnaise: I use a Japanese mayonnaise that's a bit healthier than Kewpie mayo. It doesn't contain additives. Outside of Japan, you can find Kewpie mayonnaise. The good thing about Kewpie is that it doesn't contain added sugar.
Salmon: I made this recipe with Alaskan salmon, which was ideal. It's also funny because I live in Japan, which is actually pretty close to Alaska. I recommend using fresh ocean-caught salmon if it's within your budget.
Salt: Maldon Sea Salt is my go-to salt. I'm sure your sea salt of choice or kosher salt will do the trick too!
Avocado: It's best if you can find an avocado that's not overripe. As a filling for onigiri, you don't want it to be too soft or mushy. When you press your thumb against the bottom, it should only dent in slightly to gentle pressure. And if you check underneath the stem, you want it to be a light green color.
Shiso (perilla): You may have luck finding shiso at your local Asian market. If you have no luck, it will still taste good without it. It's tough to find a good substitute for shiso. You could try adding a small amount of mint or basil as an experiment. Or you can do what my sister does in Minnesota and grow shiso in your garden.
Wasabi: Freshly grated wasabi would be amazing (and expensive!) I used just a regular wasabi in a tube. S & B Wasabi contains real wasabi with some additives. Most wasabi outside of Japan is fake but it will still work.
Sesame seeds: I used organic sesame seeds and ground them into a powder with a Japanese mortar and pestle called a suribachi. If you don't own a mortar and pestle, I'd just use a plastic Ziplock bag and a rolling pin (or spoon).
How to Make Onigiri with Fillings
Expert Tips:
- When you press the center of your ball of rice to make an indentation, make it deep and wide. You want ample space to stuff lots of filling.
- Keep in mind that the more fillings you stuff in the middle, the more challenging it will be to enclose the filling. If it's your first time, I recommend you err on the side of not overfilling your onigiri. When you attempt your next batch, you can challenge yourself to add more fillings. That's my preference, so the person eating my onigiri isn't disappointed by a lack of filling.
- Once you've stuffed fillings inside the indented space, "the cave", you can use a spoon, chopsticks, or your fingers to press the fillings in to make space for adding more. Again, you have to use your judgment so you don't overdo it.
- Cup the palms of your hand to enclose the filling inside the indented space, closing the opening tightly until you can no longer see the fillings. If needed, sometimes I'll patch up anywhere the fillings are showing through with a small bit of rice. Dip your fingers in your bowl of water so the extra rice doesn't stick.
- If you're struggling to enclose the fillings inside your onigiri, try placing a scoop of rice on top of a piece of plastic wrap inside a small bowl. Add the filling in the middle and then cover it with another scoop of rice. Then, twist the plastic wrap tightly to help mold the onigiri into shape.
- To learn the basics of making simple (and easy) onigiri, check out my recipe for making onigiri with no fillings. It's a lot easier.
Different Fillings for Onigiri
Traditional Fillings
These are the 12 most popular onigiri fillings in Japan (Ranking Net). The first seven you'll easily find at almost any convenience store in Japan.
- salmon- shake
- salt- shio
- tuna mayo- tsuna mayo
- salmon roe- ikura
- bonito flakes- okaka
- spicy cod roe- mentaiko
- simmered kelp- konbu
- kalbi (grilled ribs)- karubi
- Japanese fried chicken- kara-age
- raw fatty tuna with green onion- negitoro
- cod roe- tarako
- pickled plum- umeboshi
Creative Fusion Onigiri Fillings
It's easier to stick with the standard fillings because we know that they work. But I don't think that should stop you from getting creative. Why not start an onigiri revolution in your kitchen? I say go for it!
There are a few things to keep in mind before you get creative:
- It's important that you choose ingredients that match the taste of rice and seaweed if you're wrapping them with nori. When I was testing my filling recipe, I experimented with lemon zest on top. Lemon didn't go with the taste of nori seaweed or the rice.
- Choose ingredients with a firm texture. I knew cooked salmon would work but I wasn't so sure about avocado. Avocado turned out ok. But I was choosy about buying avocados that were just beginning to ripen. I recommend you avoid ingredients that don't have a firm structure. Umeboshi (pickled plum) is a good example of a filling that is firm enough.
- Choose ingredients that aren't too wet. Even though the rice is compacted into a ball, soupy ingredients will leak through. Creative filling combinations will be more challenging to keep from leaking. Especially if you plan to wrap your onigiri to eat later, you'll want to keep this in mind.
Fun, Fresh Ideas for Creating your own Onigiri
I brainstormed some more fusion-filling ideas to create your own onigiri with a modern twist:
- canned tuna, avocado, and mayonnaise (maybe with finely sliced cucumber)
- grilled shrimp, ginger, and chopped cucumber (with soy sauce or ponzu)
- spicy sriracha chicken
- Mexican-seasoned taco onigiri (How about with melted cheese?)
- ramen egg (ajitamago) with sautéed shiitake mushrooms and spicy mayo
- grilled miso chicken with eggplant
- scrambled eggs, grilled salmon, and konbu
You could even turn these into amazing yaki onigiri toppings. Let me know if you try!
What are your creative ideas that you're thinking about trying? I'd love to hear them in the comments below!
What to Serve with Onigiri with Fillings
As a general rule, miso soup and tsukemono (pickled vegetables) pair perfectly with onigiri.
If you decide to use the fillings in my recipe below, I would serve it with simple sides like plain tamagoyaki with no fillings, miso soup, and easy-to-make Japanese-style pickled vegetables.
If you're preparing a Japanese meal, something like yakitori on the grill, I would serve these onigiri at the end of the meal. It's a fun surprise, especially if your dinner guests have never tried fusion onigiri before.
Onigiri with fillings also go well with these savory, umami-ful dishes:
- Korean rolled omelette
- low carb okra with eggs and crispy mozzarella
- bitter melon with eggs
- tamagoyaki
And in Japan, a lot of times people will eat one or two onigiri as a snack or light meal. Especially these ones with fillings, you can enjoy them just with a cup of green tea. They're good eatin' all on their own!
Storage and Reheating Tips
Onigiri with fusion fillings tend to not keep as well as traditional ones. Ask anyone who has gotten creative with onigiri fillings before. They'll likely get soggy if you try to store them for a couple of hours.
But if you have to keep them for later, follow these guidelines.
- Unless you are going to eat your onigiri immediately, it's important to salt your rice. Adding salt and letting the rice cool is crucial for proper hygiene. The salt helps to delay spoilage.
- Once your onigiri have cooled down to room temperature, wrap them completely in plastic wrap and put them in the fridge. Alternatively, store in a reusable container with a tight-fitting lid and refrigerate. I recommend eating refrigerated onigiri by the next day.
- If you are going to add some of the fillings to the tops of your onigiri (as pictured above), I recommend keeping some extra fillings and adding the toppings right before consuming for best results.
- I prefer to refrigerate onigiri without wrapping the rice balls with nori seaweed. The nori will stick to the rice, get soggy, and lose all its crispness. Before eating, you can wrap your onigiri with a fresh, crisp sheet of nori.
- Freshly made onigiri can be put in bento boxes in the morning and eaten as is for lunch. Using a bento box is the most environmentally friendly way to store onigiri. You could also use an onigiri case with a Nintendo character on it.
- Typically, onigiri are not reheated. You can try putting them in the microwave after removing the plastic wrap for 10-15 sec intervals until warm.
Frequently Asked Questions
Is it better to make onigiri warm or cold rice?
To make onigiri with fillings, using freshly cooked rice is ideal. The stickiness of freshly cooked warm rice makes it easier to form into a ball. Remove from your rice cooker and let the rice cool. Let it cool just enough that you can hold it (like a "hot potato") in your bare hands. When the clouds of steam rising from the rice have mostly dissipated, lightly touch it with your fingers to test the temperature.
If your rice has been refrigerated or frozen, you should warm it before making onigiri.
How long can onigiri be stored?
In general, onigiri can be kept in the fridge overnight and consumed the following day. However, how long your onigiri will keep depends on the fillings. The challenge with experimenting with creative fusion fillings is sogginess. The best-case scenario is eating your onigiri fresh or as soon as possible.
Can onigiri be made the night before?
Yes, but I wouldn't recommend it. Onigiri don't taste nearly as good when they're kept refrigerated overnight. If that's the only time that works for your schedule, you could try reheating them to bring back some of the fresh taste.
Should I add rice vinegar to onigiri rice?
Traditionally, rice vinegar is not added to rice to make onigiri. Vinegar, sugar, and salt are used to make seasoned sushi rice, not onigiri. These two easily get confused because both are made with rice and seaweed.
That's not to say that vinegar is never added to onigiri as seasoning. It will add a nice tang if that's what you're shooting for.
Onigiri Fillings Recipe — Japanese Rice Balls (Easy)
Ingredients
Rice
- ¾ cup Japanese short-grain rice equal to one "rice cooker cup"
- 200 ml water ⅞ US cup
- ¼ tsp salt fine-grained sea salt or kosher salt
Fillings (& Topping)
- 1 tsp mayonnaise
- 1 fillet salmon
- 2 pinches sea salt
- ½ avocado medium size
- 4 leaves shiso perilla
Wrap and Wasabi Mayo Drizzle
- 1 sheet dried nori seaweed
- 1 tbsp ground white sesame seeds
- 1 tsp mayonnaise
- ½ tsp wasabi
Instructions
Filling and Topping (prep)
- Cut half of an avocado into small chunks. Set aside.
- Rinse and dry shiso leaves with paper towel. Remove the end of the stems and finely slice leaves into thin strips. Set aside.
- Sprinkle sea salt on top of the salmon fillet. Set aside.
- Add wasabi and mayonnaise to a small dish. Use chopsticks or a spoon to mix together. Cover and keep refrigerated until needed.
Fillings (cooking)
- Turn on stove to low heat to pre-heat pan for 1-2 minutes.
- Add mayonnaise to the center of pan and spread out with a spoon to make a vertical line.
- Place salmon fillet directly on top of mayonnaise. Turn up the heat slightly.
- Once salmon is nearly halfway cooked through, use a spatula to turn fillet over.
- When salmon is nearly cooked through, add avocado chunks to the pan. Continue to cook on low-medium heat.
- Add sliced perilla leaves on top of salmon fillet and avocado.
- Using a spatula, break apart salmon into bite-sized pieces and gently mix all the filling ingredients together.
- Once the salmon is cooked through and all the ingredients are mixed together, use a spatula to scoop the fillings mix into a bowl.
Preparing Rice
- Transfer freshly cooked rice from your rice cooker or pot to a large bowl or glass baking dish.
- Using a spatula, gently spread out the rice to cover the bottom of your bowl.
- Sprinkle with salt (¼ tsp) and mix into rice by lightly tossing and folding over.
- Cool the rice until you no longer see clouds of steam and the rice has cooled just enough that you can hold it in your bare hands.
Shape Onigiri by Hand
- Fill a bowl with room temperature water and a small dish with salt. Keep these nearby to use as needed.
- Using your spatula, divide the cooked rice into three equal sections in your bowl or pan.
- Dip both of your (immaculately clean) hands into your bowl of water. Shake off the excess water.
- Next, lightly dip your wet fingers into a small dish of salt. Rub the salt to cover your palms.
- Using your hands or spatula, scoop up enough rice to make one onigiri.
- First, like making a snowball in two hands, gently form the rice into a sphere. Make it a ball shape but not too compact.
- Press the center of your ball of rice to make an indentation. Make it deep and wide. You want ample space to stuff lots of filling.
- Stuff fillings inside the indented space. You can use a spoon, chopsticks, or your fingers to press the fillings in to make space for adding more until the space is completely full and compacted.
- Cup the palms of your hand to enclose the filling inside the indented space, closing the opening tightly until you can no longer see the fillings.
- Place the sphere of rice in the palm of your non-dominant hand. Bend your palm to make a v-shaped "valley".
- Bend the fingers of your other hand to make an upside-down v-shape. Cover the rice ball with your V-shaped dominant hand. Your dominant hand makes a "mountain" to cover the rice— think Mt. Fuji.
- Then, gently squeeze the rice ball with your top v-shaped hand to form one corner of a triangle.
- Next, flip the rice ball 90 degrees towards you. The first corner of your triangle should now be resting on the palm of your bottom hand.
- Again, gently squeeze with your top, v-shaped hand to form another corner to make a triangle.
- Repeat this rotate and squeezing process until you've made a neat triangle shape.
Wrap Onigiri with Nori Seaweed
- Cut nori seaweed sheet into strips. I prefer to cut strips ⅓ of a full-size sheet.
- Hold the onigiri in one hand. Lay the strip of nori horizontally across the bottom third of the rice ball. The shiny side of the nori strip should face out and the rougher side faces the rice ball.
- Fold the left and right ends of the nori strip around the sides of the onigiri. The nori should come together at the front of the onigiri, resembling the way a kimono is wrapped.
- Press the nori gently against the rice to help it stick.
- Tuck the ends under the two bottom corners and base of the onigiri triangle. Again, press gently until the ends stick to the rice.
- Stand the onigiri vertical on a plate.
- Sprinkle ground white sesame seeds over the top.
- Using chopsticks, spoon, or clean fingers, add extra fillings on top corner of onigiri. You'll need to balance the toppings just right so they don't topple over.
- Drip wasabi mayo over the toppings.
- Serving onigiri warm for the best taste. Or, set them aside to let them cool to room temperature.
Notes
Check out my recipe dance videos to see how I made these fillings in a fry pan:
And follow me on Instagram for more healthy Japanese food edutainment!
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