Hakumai (White Rice) (白米)
Hakumai (white rice) is polished brown rice. It is also called seimai (polished rice) or seihakumai (polished white rice).
The term seimai is used to mean the act of polishing the rice as well as the white rice itself; other expressions for the act of polishing include seihaku and tosei.
Summary
As the name implies, it is whiter and more transparent than the brown rice it comes from.
It is cooked both for eating directly and also used as an ingredient in processed food and seishu (refined sake).
The 'Standard for Seishu Production Process Quality Indications' is defined in the following way by Japanese National Tax Agency Notification 8, of November 22, 1989.
Hakumai shall refer to polished brown rice ranked as third grade or higher by the Agricultural Products Inspection Act (Act 144, 1951) or equivalent brown rice.'
When brown rice is cooked in a normal rice cooker rather than a pressure cooker, its rice bran layer is difficult to digest, and the texture is dry and poor. In contrast, cooked white rice is good for the digestion, has a better texture, and is considered more delicious.
Compared to brown rice cooked in a pressure cooker, it has a light taste which goes well with accompanying dishes as a staple food. This is similar to the difference between brown sugar and white superior soft sugar.
The germ and bran layer which is scraped off is full of nutrition, so white rice which contains only starch and albumen is not well balanced nutritionally.
Though people have been known to say 'I wouldn't need any other type of food if I had good rice' this is not possible nutritionally.
The more starch in the rice, the stickier the cooked rice becomes, and the more favorable to the palate of the average Japanese consumer. Such 'delicious rice' has far fewer components other than starch, such as protein.
White rice has had the outer layer removed during the polishing process, so it deteriorates more easily due to oxidation as days go by. Therefore people usually purchase it in comparatively small amounts to maintain freshness. Cold storage is preferable.
In earlier times rice pounded by a mortar was called 舂米 (pronounced shomai, tsukishine or tsukiyone, the first character of which is not to be confused with the similar looking character for spring '春').
It is said that, in ancient times, women worked with a mortar and pestle, and a Department of Shomai was especially established in the miyake (Imperial-controlled territory) in the Yamato Dynasty.
Ordinary people were constrained from eating white rice before the Meiji Period. But the abolition of this rule in the Meiji Period, meant that ordinary people could also start to eat white rice.
However, the economically-challenged were not able to afford enough accompanying dishes to compensate for the loss of nutrients from eating white rice. For this reason it was once said that beriberi was the Japanese national disease.
In Japan, it is rare to consume brown rice as it is. Rice is overwhelmingly polished and divided into white rice and rice bran, and sold and used respectively.
Sprouted brown rice, which suits being cooked in a normal rice cooker better than standard brown rice, has recently appeared on the market. But white rice has been established as the de facto standard in retail for consumers.