Rice cooker

thumb|right|Electric induction rice cooker with scoop

A rice cooker or rice steamer is an automated kitchen appliance designed to boil or steam rice. 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.

thumb|right|Traditional rice cooker commonly used by people of [[Indonesia in the Netherlands in 1950s. Showcase on display at the Eurasian festival Tong Tong Fair 2012.]]

The term rice cooker formerly applied to non-automated dedicated rice-cooking utensils, 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 (, literally, "boil-rice-device"). It was a simple mechanism that heated with an attached heating coil without automation.

In the 1940s and early 1950s, Mitsubishi Electric, Matsushita Electric (now Panasonic), and Sony introduced electric rice cookers for home use with built-in heating coils, but they too were not automated and were not well received and sold poorly. introduced by Toshiba on December 10, 1955 Research and development was a continuous process of trial and error, including experimentation carried out by Minami's wife Fumiko. Research showed that rice cooks best when cooked at a temperature of for 20 minutes, so theoretically rice should cook well if an automatic timer is set to turn off the cooker 20 minutes after the water in the pot has boiled. However, the time it takes for the water to boil varies depending on the temperature, the amount of heat generated by the pot, and the amount of rice and water, so in the prototype stage, sometimes the rice was overcooked and burnt, while at other times it was undercooked and the rice was left with a core. The revolutionary idea to solve this problem was to use a double-layered structure for the pot. The mechanism involved filling the outer pot with a glass of water and heating it. After about 20 minutes, the water would evaporate and the temperature would rise rapidly, which the thermostat would detect and turn off.

In 1972, a rice cooker with a heat-retention function was introduced, and in 1979, an electronic rice cooker equipped with a microcomputer that could also manage the soaking of rice after washing and the heat level. In 1988, rice cookers with electromagnetic induction heating were introduced, which provided higher heating.

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.

Rice cookers are usually sold with a rice paddle and a measuring cup included. The measuring cup is typically 180 ml or roughly one gō, a traditional Japanese unit of volume.

More advanced cookers may use fuzzy logic for more detailed temperature control, induction rather than resistive heating, a steaming tray for other foods, and even the ability to rinse the rice.

Many models feature an ability to cook sticky rice or porridge 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").

Other uses

Steam rice cookers have been shown to be effective for decontamination of face masks.

Other uses

See also

References

Further reading