Rice Balls (onigiri) are a popular Japanese food that is made by packing white rice into a triangle or oval shape. More often these have some form of filling in the middle.
Rice Balls are known in Japan as Onigiri (お握り/おにぎり) or Omusubi (お結び). The spelling on the use of kanji can vary. This dish is a rice-based staple of Japanese cuisine, the equivalent of sandwiches to Western cultures; and more often contains various fillings and wrapped in nori seaweed, They are often formed in triangles or ovals. The popularity of this dish is large enough in Japan and many other Asian cultures that nearly all convenient stores stock pre-made rice balls with filling options.
There is a widely held misconception that sushi and rice balls are similar forms. This comes from the concept that they are both rice based and wrapped in nori. The differences are in the rice. Rice balls are made using plain rice, but sushi is produced as rice with vinegar, sugar and salt.
The creation of rice balls has been dated as far back in Japanese culture to before the widespread use of chopsticks as an eating utensil in the Nara Period (710 to 794 AD). It was the original creation designed to be easily transported food.
One of the oldest written records of rice balls was found in the works of the 11th century Japanese novelist, Murasaki Shikibu, in the The Diary of Lady Murasaki (紫式部日記 Murasaki Shikibu Nikki), which was written some time between 1008 and 1010. Though, in that era they were called "tonijiki (屯食)". Seventeenth century writings described samurai would keep packed rice balls in bamboo leaves for their meals.
The dish became more of a major staple by the Kamakura Period (1185 to 1333AD) and to the early Edo Period (1603 to 1868 AD). This was partly because of the simplicity of design and ease of how it was prepared. Nori wrappings didn't become as widely used until it was more more easily accessible in the Genroku Era (688 to 1704 AD), and it was produced in sheets.
Rice balls didn't become mass produced until 1980s. The style of hand packing and molding made many feel that rice balls needed to be hand crafted, but eventually a triangular press was created to make mass production molding of rice balls easier. This style was met with much criticism since the fillings were injected into the rice balls from the outside. The hole covered by nori. being packed along with the nori would make these versions sticky and wet. Eventually, the nori was packaged separately with the rice balls. As technology in mechanics improved, they were able to made the variety of fillings more available, and packaging designed improved to keep the rice and nori separated until it's unwrapped.
The following recipe for making rice balls is designed to create up to eight servings. To reduce the serving sizes, the measurements will needed to be adjusted to your needs, but this could possibly also effect some of the cooking times.
Watch the rice in cold water at least 30 to 60 minutes before preparation and leave to drain. Place the rice with the 4 1/2 cups of water in a well covered saucepan on medium-high heat. Just as a boil begins, turn the heat to high and leave until a high boil is reached. Quickly reduce the heat to low and leave until all teh water has been absorbed by the rice. This can take from 12 to 13 minutes. Now, remove from the heat and leave the rice covered for 10 to 15 minutes. Gently break up the rice with a flat spoon or paddle with gentle cutting motions. Cover with a tea towel to keep the rice warm.
Toast your two sheets of nori over a high heat flame and cut into 1 inch strips. However, pre-toasted nori could be an option if available.
You will need to wet your hands with slated water to avoid sticking while you mold your rice balls. You can also wet your hands in cold water then sprinkle with salt. Grab about 1/2 cup of rice in your cupped hand. Make an indentation with your free thumb into the rice to place your filling (average amount of 1 tsp. Close the rice over the hole and use your hands to mold into a triangular shape or ball. Bet sure to press firmly as you mold so that the rice will hold it's shape. Place down on one side and place your sheet of nori. You can then sprinkle with sesame seeds if desired.