How To Reheat Onigiri – I Test 5 Methods [Pics]

This article was updated on 26/07/2023 for clarity and to incorporate newly tested methods.

Onigiri is the perfect on-the-go snack, but they taste better warm. Sadly, reheated rice often becomes congealed and dry with an unpleasant chewy texture.

To prevent this happening to you, I tried five different onigiri reheating methods to find out which one best revitalized their freshness and flavor.

In a rush?

The easiest way to reheat onigiri is in the microwave. Wrap the onigiri in a damp paper towel and heat them on 50% power in 20 second bursts. You can also fry them with soy sauce to make yaki onigiri or break the rice up and pour hot green tea over it to make ochazuke.

A note on my experiment

I prepared some onigiri but overestimated how hungry I was, so ended up with a few too many. Lucky for me, this meant I could snack on them again the next day.

Wanting to retain their original savory, salty flavor and moist, sticky texture, I tried a few different reheating methods. I tested:

• Microwave: Best method overall.
• Frying pan: Revamps onigiri with a delicious crunch.
• Steaming: Good for reheating larger quantities.
• Hot tea: Surprisingly good comfort food.
• Oven: Not recommended.

Reheating onigiri in the microwave

Time: 20-40 seconds
Rating: 9/10

1. If present, remove any nori from the onigiri and set aside (to keep it crispy).
2. Wrap your onigiri tightly in a damp paper towel* and place it on a microwave-safe plate.
3. On medium heat (50%), microwave in 20-second increments until hot.
4. Replace the nori and serve immediately.

*Alternative: in a microwave-safe bowl, sprinkle onigiri with water and cover the bowl with plastic wrap, then follow the rest of the steps above.

Adding moisture using a damp paper towel or a sprinkle of water helps rehydrate the onigiri. You can also microwave onigiri securely wrapped in microwave-ready plastic film (and get great results), but not everyone will be comfortable with this. The USDA don’t advise letting plastic wrap touch your food in the microwave. 

Be mindful that the onigiri will warm quickly, so 20 to 40 seconds will be enough. Too long in the microwave will leave you with dry rice and a chewy texture.

Results: This technique was quick, practical, and kept the onigiri soft and moist. A significant perk of the microwave method was that it warmed the onigiri up evenly. No more biting into boiling hot rice and discovering a cold inside!

Reheating onigiri in a frying pan (making yaki onigiri)

Time: 6 minutes
Rating: 9/10

1. If present, remove any nori from the onigiri and set aside.
2. On medium heat, warm up some butter or oil in a pan then fry onigiri for two minutes on each side.
3. As an optional step, brush your onigiri with soy sauce*.
4. Fry for a further minute on each side or until a crust develops.
5. Remove from the heat, replace your nori, and serve hot.

*Soy sauce is traditionally used to develop the crunchy outer layer of yaki onigiri, but you can also use teriyaki sauce or sweet miso, depending on your flavor preference.

The result of this is a delicious dish known as yaki onigiri. It’s the perfect way to revive old onigiri that’s turned stale so wouldn’t be saved by the microwave or steaming.

I like to use sesame oil when reheating onigiri in a pan, but any soluble fat works, including vegetable oils, bacon grease, and butter. Be mindful of the temperature of your pan. Too hot, and the onigiri will burn on the outside but remain cold in the center.

Results: Making yaki onigiri would be my go-to method if I had a bit of extra time on my hands. The onigiri was moist and flavorful on the inside and crispy on the outside. Next time I’ll try miso… yum.

Reheating onigiri in a steamer

Time: 3-4 minutes
Rating: 8/10

1. Set up your steamer and bring the water to a simmer.
2. Remove nori if present and set aside.
3. Line your steamer basket with perforated baking paper and spread your onigiri out in the basket.
4. Cover with a lid and steam for 3 to 4 minutes.
5. Remove the onigiri from the basket, replace your nori, and serve hot.

Lining your steamer basket with baking paper prevents your onigiri from sticking to the basket. But make sure you perforate the paper (poke some holes in it) so the steam can still rise effectively.

If you don’t have any baking paper, you can also use cabbage or lettuce leaves.

If you fancy adding a bit of extra flavor to the rice, use stock instead of water in the steamer.

Results: My steamed onigiri was soft and warm all the way through, with a delicious salty flavor. It’s an excellent method for reheating a few onigiri at a time.

Reheating onigiri with hot tea (ochazuke)

Time: 3-4 minutes
Rating: 9/10

1. Break up your onigiri in a bowl so the rice is well separated.
2. Make a cup of hot green tea.
3. Pour the green tea over the rice and add in a few drops of soy sauce and a pinch of wasabi if you have it.
4. Add any toppings you have to hand (eggs, herbs, sesame seeds, nori, spring onions, flaked salmon, pickles etc).
5. Wait 1-2 minutes for the tea to warm the rice and dig in.

This isn’t so much a reheating method, but more of a way of transforming your leftover onigiri into something different, but just as delicious.

If you’re not a fan of green tea, you can also use dashi or even a light chicken or vegetable stock as the liquid. And don’t stress about the toppings, they’re meant to be a random mix of whatever you have lying around the house!

Results: Ochazuke (with ‘ocha’ meaning tea, and ‘zuke’ meaning submerged), is now one of my favourite warming comfort foods! I loved it! And you can even make it on the go if you bring a flask of hot tea with you.

How to store onigiri

To store onigiri, remove any nori and wrap the onigiri securely in plastic wrap. Then place them in the fridge for up to 3 days. Optionally, fold a dishcloth over your plastic-wrapped onigiri to reduce the harshness of the cold air in the fridge.

The fridge will dry out the rice, so it’s essential to cover your onigiri tightly to retain moisture and keep out air. Otherwise, you’ll end up with stale, hard rice cakes.

The nori will turn soggy in the fridge. For maximum crunch, store nori separately in a moisture-free sandwich bag (with all the air sucked out). Alternatively, place your nori against the plastic-wrapped onigiri and cover with a second layer of plastic wrap.

Related: How To Store Mochi

How to freeze onigiri

Remove any nori from your onigiri and wrap them tightly in plastic wrap. Place your wrapped onigiri in a freezer or zip-lock bag, removing as much air as possible (I suck it out with a straw). You can store onigiri in the freezer for up to two months.

To keep your onigiri as fresh as possible, prioritize minimizing air exposure. The tighter the wrap, the less likely air is to enter and dry out your rice.

The double layer of plastic wrap and freezer bag goes a long way to preventing freezer burn. If you’re opposed to plastic, onigiri can also be stored wrapped in parchment paper.

How to reheat frozen onigiri

Always reheat frozen onigiri straight from the freezer. Never let onigiri thaw naturally. Wrap the frozen onigiri in a damp paper towel and heat it in the microwave in 30 seconds intervals until soft and warm.

If you let the onigiri thaw to room temperature on its own, the outer layers of rice will dry out and turn hard, while the inside will turn soggy and mushy.

How To Reheat Onigiri [Tested Methods]

Reheated rice often becomes congealed and dry with an unpleasant chewy texture. To prevent this happening to your onigiri, I’ve tried five different reheating methods to determine which one is best for revitalizing the freshness and flavor.

5 from 1 vote

Print Pin Rate

Course: Snack

Cuisine: Japanese

Keyword: onigiri, reheat onigiri

Prep Time: 1 minute minute

Cook Time: 1 minute minute

Total Time: 2 minutes minutes

Servings: 1 person

Calories: 180kcal

Ingredients

• 1 piece onigiri

Instructions

• If present, remove any nori from the onigiri and set aside.
• Wrap your onigiri tightly in a damp paper towel* and place it on a microwave-safe plate.
• On medium heat (50%), microwave in 20-second increments until hot.
• Replace the nori and serve immediately.

Notes

*Alternative: in a microwave-safe bowl, sprinkle onigiri with water and cover the bowl with plastic wrap, then follow the rest of the steps above.

Nutrition

Serving: 1piece | Calories: 180kcal