How to reheat onigiri

Onigiri is a delicious snack that tastes better when eaten warm. Wrap it tightly in a damp paper towel. Place it on a microwave-safe plate or stove plate. Serve immediately. Reheated rice becomes dry when not done well.

To prevent this, choose the best amongst the three different reheating methods to determine which one will best revive their freshness and flavor. That is in the microwave, frying pan, and steamer, which is for reheating large quantities.

Frying pan

Making onigiri using a frying pan is ideal if you have extra time on your hands. The onigiri is left moist and flavorful on the inside and crispy and crunchy outside. You can get creative with the flavor profiles by brushing the onigiri with different coatings. Keep the heat low to avoid overcooking (Greatist.com).

Steps

1. Remove nori from the onigiri and set it aside if present.
2. Use sesame oil when reheating onigiri in a pan. Beware of the temperature of your pan. Use medium heat to warm up some butter or oil. Too hot, and the onigiri will burn on the outside but remain cold in the center.
3. Fry onigiri for two minutes on each side.
4. Brush your onigiri with soy sauce if you want. Soy sauce develops the outer layer of onigiri. Use teriyaki sauce or sweet miso, depending on your flavor preference.
5. Fry for another minute on each side or until a crust develops.
6. Remove from the heat, replace your nori, and serve hot.

Steamer

Steaming is for reheating frozen foods and foods that stick together (Garlicdelight.com). Steaming onigiri softens the rice and warms them through. It is an ideal method for reheating onigiri. Overheating them will leave you with mushy, soggy rice that is not enjoyable.

Steps

1. Set up your steamer.
2. Bring water to a simmer.
3. Remove nori if present and set aside.
4. Line your steamer basket with perforated baking paper. Lining your steamer basket with baking paper prevents your onigiri from sticking to the basket. Spread them to avoid attaching. Poke some holes in your baking paper so the steam can rise. Use cabbage or lettuce leaves as an alternative.
5. Spread your onigiri in the basket and place over simmering water.
6. Cover with a lid and heat for up to 5 minutes. Check on the onigiri often so you do not overheat them.
7. Remove them from the basket, replace your nori, and serve hot.

Although the method is a better alternative to the microwave, it is not convenient or practical. However, the results of the onigiri come with soft stickiness and salty flavors. The steam penetrates through the rice cakes, warming them evenly. When reheating onigiri for a few people and having the time, using the steamer method is better and will not give you difficulties. 

Oven

You can reheat onigiri in the oven. The onigiri has to be soft, sticky, and moist. The oven will dry the rice out, and it ends up with chewy, dry rice that wants to fall apart even if you add moisture before heating it.

Steps

1. Set your oven to 300°F (150°C). 
2. Remove nori, if present, and set aside. 
3. Sprinkle your onigiri with water and wrap it in tin foil. 
4. Heat them for five minutes or until warm. 
5. Remove them from their foil.
6. Replace your nori, and serve hot.

Best method

Microwave

The paper towel method and the covered bowl method produce soft, flavorful onigiri in less than a minute. The microwave is best known for convenience.

Steps

1. Remove the onigiri’s outer layer of nori only if it is there. Wrap your onigiri in a sheet of damp paper towel, or sprinkle it with water and place it in a bowl covered with plastic wrap. 
2. Microwave on 50% power in 20-second increments until hot. 
3. Replace the nori and serve.

There is an alternative method when using a microwave. Use a microwave-safe bowl, sprinkle onigiri with water, cover the bowl with plastic wrap, and follow the steps above.

Adding moisture using a damp paper towel or sprinkled water keeps your onigiri moist and soft. Be careful that it warms quickly, so 20 to 40 seconds should be enough. If you keep it too long in the microwave, you will have dry onigiri with a chewy texture.

Do not microwave too many onigiris at once. Two is better than a limit. Too many onigiris heat more unevenly. If your onigiri has an outer layer of nori, remove it before reheating to prevent it from becoming soggy. It will retain its crispy crunch when you replace it post-reheating. The method is quick and practical, and consistent.

Storing Onirigi

If you keep your onigiri at room temperature, look closely at the ingredients. Plain rice onigiri can stand at room temperature for six hours or 8 hours with a natural preservative. If it contains perishable fillings, keep it within two hours.

Refrigerated Onigiri will last up to three days, but onigiri with a mayonnaise-based filling stays fresh for one to two days. Frozen Onigiri is suitable for up to two months. Remove any nori and wrap the onigiri in plastic wrap. Fold a dishcloth over your plastic-wrapped onigiri to keep them cool and safe without exposing them to cold air. 

You will not have stale, hard rice cakes and soggy rice. The fridge tends to dry out rice, so you have to cover your onigiri to retain moisture and keep out air. For maximum crunch, store nori separately in a moisture-free sandwich bag. 

You can place your nori against the plastic-wrapped onigiri and cover it with a second layer of plastic wrap. Store onigiri in the freezer for up to two months. Remove nori from your onigiri and wrap them in plastic wrap. Place your wrapped onigiri in a freezer or zip-lock bag and remove air.

Safe Temperatures 

Heat your onigiri at 150°C. It withstands room temperature for 8 hours, refrigerates for two days, and freezes for two months.

FAQs

How to reheat frozen onigiri?

Reheat frozen onigiri straight from the freezer. Never let onigiri thaw on the counter. Wrap the frozen onigiri in a damp paper towel and heat it in the microwave in 30 seconds intervals until soft and warm. You can heat onigiri in a bowl and cover it with plastic wrap.

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 mushy.

Can you eat onigiri cold?

You can eat them cold, but you can heat them or let them warm to room temperature. Cold onigiri sometimes takes on a greasy texture.