How to Reheat Onigiri (And Keep it Oishii!!!)

Onigiri is delicious and convenient, especially as izakaya (pub grub) when you’re in between drinks when touring Japan and enjoying the local club scene. It’s nowadays available worldwide in many fast-food outlets. The steamed rice wrapped in roasted seaweed is best served hot and dabbed in soy sauce and perhaps a little wasabi. However, when served fridge cold it can be a little off-putting. 

When reheating Onigiri you want to retain the delicate flavors, crispy outside, and tender inside. The easiest way to reheat Onigiri is using a microwave. A steamer or frying pan presents other good reheating options. An oven may not be best but still can be used to reheat onigiri. 

Read on to explore several ways you can reheat onigiri while maintaining its shape, flavor, and texture. 

How to Reheat Onigiri in the Microwave

Whether you’re reheating onigiri bought from your favorite conbini (convenient store) or warming up your homemade leftover, the simplest and easiest way to reheat is in the microwave. For best results:

1. Remove the nori (roasted seaweed wrapping) and set it aside.
2. Wrap your onigiri (the ball of steamed rice) tightly in microwave-ready plastic wrap. This retains the shape and ensures the soft inside doesn’t dry out and falls apart. 
3. If you store the onigiri in the freezer, don’t let it thaw first. Heat it frozen so it retains as much moisture as possible. 
4. Do not reheat many pieces together, otherwise they will heat unevenly. Place only one or two onigiri at a time.
5. Warm in the microwave in the reheat setting. For older microwaves, use a low temperature setting for 30 seconds to one minute.
6. Replace the nori and serve

How to Reheat Onigiri in the Steamer

Steaming your onigiri is an excellent way to reheat as it warms evenly and softens the rice. To reheat your onigiri in a steamer:

1. Put some water in the bottom pan. 
2. Bring to boil and place the perforated top pan. 
3. Lower the temperature a little so the water comes to a uniform simmer
4. Remove the nori from the onigiri. 
5. Line the top pan with a perforated baking sheet and place the onigiri on top.
6. Cover with the top lid and let the onigiri warm for at least 3 minutes. 
7. Remove the onigiri and replace the nori then serve.

How to Reheat Onigiri in a Frying Pan

Reheating onigiri in a frying pan can add some new flavors and boost the original piquant fragrances. It’s also the best way to restore onigiri that was borderline going stale. The easy steps are:

1. Unwrap the nori and set it aside
2. Heat the frying pan to medium heat
3. Warm up some melted butter, sesame oil, or olive oil. 
4. Shallow fry the onigiri for a couple of minutes on each side
5. Dab a few drops of soy sauce or teriyaki sauce and keep warming for another minute on each side to develop the crunchy layer
6. Remove the onigiri from the pan and wrap it with the nori. Serve hot. 

How to Reheat Onigiri in an Oven

Reheating onigiri in an oven is not the most ideal way to restore the flavors and texture. Nonetheless, an oven can work to accentuate the smoky flavors of fillings such as grilled fish or chicken. 

If you already have an oven running it can be a good way to make use of the heat. The best way to retain much of the original texture and bring flavors back to life is:

1. Remove the nori and place aside
2. Wrap the onigiri in aluminum foil
3. Preheat the oven to 375 degrees Fahrenheit. Avoid too much heat as the rice will dry out and become too crunchy
4. Place a baking sheet on the oven tray and then place the foil-wrapped onigiri on top. Place the tray inside the oven
5. Let it warm for about 5 minutes then remove
6. Replace the nori and serve

Frequently Asked Questions

Any additional questions on how best to reheat onigiri? Check our answers below for the most common challenges

How Do I Store Reheated Onigiri?

Reheated onigiri runs a higher risk of the rice being too dry and the fillings draining flavor. The best way to store reheated onigiri is placing inside a sealable plastic wrap with the nori wrap intact. Remove as much air as possible inside the plastic wrap before storing. 

Can I Reheat Onigiri Multiple Times?

Yes, it’s perfectly fine to reheat onigiri more than once. However, the dates should not be too far apart. After reheating the first time, make sure you reheat and consume the leftover within a day, at most two days. Discard any after the second day.  

How Long Can You Keep Onigiri in The Fridge?

The amount of time you can store onigiri in the fridge depends on the ingredients. Onigiri made with fillings such as roe and mayo may spoil within a day or two while those with pickled plums and vegetable fillings can last weeks. 

Can You Eat Cold Onigiri?

Some people prefer to only thaw out their onigiri to room temperature than eating it cold. However, the texture of a cold onigiri can often taste greasy and congealed.