A rice cooker or rice steamer is an automated

kitchen appliance A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household functions such as cooking, cleaning and food preservation. Appliances are divided into three ty ...

designed to boil or steam

rice Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly '' Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and ''Porteresia'', both wild and domestica ...

. It consists of a heat source, a cooking bowl, and a thermostat. The thermostat measures the temperature of the cooking bowl and controls the heat. Complex, high-tech rice cookers may have more sensors and other components, and may be multipurpose.

Naming

The term ''rice cooker'' formerly applied to non-automated dedicated

rice-cooking utensils Rice-cooking utensils are tools used for cooking rice and similar foods. Dedicated rice-cooking utensils have a long history. A ceramic rice steamer dated to 1250 BC is on display in the British Museum. Rice cooking methods Rice absorbs a gr ...

, which have an ancient history (a ceramic rice steamer dated to 1250 BC is on display in the British Museum). It now applies mostly to automated cookers. Electric rice cookers were developed in Japan, where they are known as '' suihanki'' (炊飯器, literally, "boil-rice-device").

Principle of operation

A basic rice cooker has a main body (pot), an inner cooking container which holds the rice, an electric

heating element A heating element converts electrical energy into heat through the process of Joule heating. Electric current through the element encounters resistance, resulting in heating of the element. Unlike the Peltier effect, this process is independe ...

, and a

thermostat A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint. Thermostats are used in any device or system tha ...

. The bowl is filled with rice and water and heated at full power; the water reaches and stays at boiling point (100 °C, 212 °F). When the water has all been absorbed, the temperature can rise above boiling point, which trips the thermostat. Some cookers switch to low-power "warming" mode, keeping the rice at a safe temperature of approximately 65 °C (150 °F); simpler models switch off; the rice has entered the resting phase. More advanced cookers may use

fuzzy logic Fuzzy logic is a form of many-valued logic in which the truth value of variables may be any real number between 0 and 1. It is employed to handle the concept of partial truth, where the truth value may range between completely true and complet ...

for more detailed temperature control, induction rather than resistive heating, a steaming tray for other foods, and even the ability to rinse the rice.

Rice types and rice cookers

Brown rice Brown rice is a whole grain rice with the inedible outer hull removed. This kind of rice sheds its outer hull or husk but the bran and germ layer remain on, constituting the brown or tan colour of rice. White rice is the same grain without the ...

generally needs longer cooking times than white rice, unless it is broken, or flourblasted (which perforates the bran).ars.usda.gov Agriculture Research, May 2002
/ref> Many models feature an ability to cook sticky rice or

porridge Porridge is a food made by heating or boiling ground, crushed or chopped starchy plants, typically grain, in milk or water. It is often cooked or served with added flavourings such as sugar, honey, (dried) fruit or syrup to make a sweet cereal, ...

as an added value. Most can be used as steamers. Some can be used as slow cookers. Some other models can bake bread or in some cases have an added function to maintain temperatures suitable for fermentation of bread dough or yogurt. Multi-purpose devices with rice cooking capability are not necessarily called "rice cookers", but typically "multi-cookers". A rice cooker, or slow cooker, can be used in conjunction with a temperature probe and an external thermostat to cook food at a stable low temperature (" sous-vide").

History

Automatic electric rice cookers were first released in 1955 by the Japanese company

Toshiba , commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems ...

. In December 1956, the Toshiba Corporation placed the first commercially successful automated electric rice cookers on the market. Since then, millions have been sold worldwide. The rice cookers available today are not much different from the original models. The first practical electric rice cooker was invented by .

Naming

Principle of operation

Rice types and rice cookers

History

See also

References

Further reading