The surprising semi-secret ingredient in many Japanese convenience store rice balls: oil

A lot of the rice balls on convenience store shelves include oil, but it’s not to make them taste better.

Among the many wonderful things at Japanese convenience stores, perhaps the most wonderful of all are the rice balls, or onigiri, as they’re called in Japanese. Tasty, reasonably priced, and relatively healthy, you’ll find convenience store onigiri with all sort of fillings, such as salmon, chicken, and plum.

But there’s one ingredient present in a lot of convenience store onigiri that even most Japanese shoppers aren’t especially conscious of: oil.

▼ 油 = oil

Specifically, it’s vegetable oil that many convenience store onigiri have. This isn’t a new development, but since it’s something a lot of people aren’t aware of, every couple of years it gets some people in a stir when someone notices/points out “oil” on a convenience store ingredient list, like in this tweet posted this week with a photo of a plain slated rice onigiri from convenience store chain Family Mart.

▼ “Make it with just rice and salt,” the poster pleads.

米と塩だけでつくってくれよ pic.twitter.com/Lqnk6vWVye

— 健康最高 (@yrzXlZARNuPcPsv) March 26, 2023

You might assume that the oil is added as a cheap but unhealthy way to make convenience store onigiri taste better, but the truth is actually more complicated, with no fewer than three reasons for the oil. The first is texture. Adding oil to the rice before it’s cooked creates a coating for the individual grains, so that even though they’re pressed together and retain their rice ball form, there’s enough space between them for a light, fluffy consistency.

“But wait, what about homemade onigiri? Those don’t have oil in them,” you might be asking. That’s true, but unlike onigiri made at home and then eaten soon after, convenience store onigiri are made at a factory, then shipped to the chain’s branches and stocked on refrigerated shelves until they’re purchased. Without oil, the passage of time and low temperature would make the rice clumpy and hard.

The second reason has to do with how convenience store onigiri are made. Rather than being pressed by hand, they’re made with a mechanical press. The oil helps prevent rice from sticking to the machinery, which keeps the shape of the onigiri nice and consistent.

And finally, the oil in convenience store onigiri is there because of how the rice balls are packaged. They have to be wrapped in something, usually plastic, and just like how the oil keeps the grains from sticking too closely to each other, it also keeps the onigiri from sticking to the inside of its packaging, so it can be removed without inadvertently tearing off a piece of the rice ball.

▼ If this onigiri was poorly formed or sticking to its package it might spill its beefy filling before you can bite into it.

All that said, not every convenience store rice ball is made with oil. It seems like the ingredient is more common with onigiri that don’t have a nori (seaweed) wrapping.

▼ This sardine and sansho spice onigiri has oil in its ingredient list…

▼ …but this salmon onigiri, with a nori wrapper, doesn’t…

▼ …and neither does this seaweed-equipped salmon onigiri.

And thankfully, even when convenience store onigiri are cooked with oil, it’s not like the rice was boiled in a 100-percent pot of the stuff. The salt onigiri from 7-Eleven pictured at the start of this article has a total of 0.9 grams of fat, and the onigiri pictured in the tweet, from rival chain Family Mart, has only slightly more fat, 1.1 grams. So even if convenience store onigiri aren’t always entirely oil-free, they’re still a pretty healthy snack choice, so the main thing to worry about is whether or not you can open the wrapper the right way.

Source: Hachima Kiko, Shukan Josei Prime
Photos ©SoraNews24
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