
A rice cooker or rice steamer is an automated
kitchen appliance designed to boil or steam
rice
Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...
. 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.
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
The British Museum is a Museum, public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is the largest in the world. It documents the story of human cu ...
). It now applies mostly to automated cookers. Electric rice cookers were developed in
Japan
Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
, where they are known as ''
suihanki'' (, literally, "boil-rice-device").
History

The NJ-N1, developed by
Mitsubishi Electric
is a Japanese Multinational corporation, multinational electronics and electrical equipment manufacturing company headquartered in Tokyo, Japan. The company was established in 1921 as a spin-off from the electrical machinery manufacturing d ...
in 1923, was the first electric rice cooker, a direct ancestor of today's automatic electric rice cookers. At that time, electricity was not widely used in ordinary households; it was for use on ships.
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
is a Japanese multinational electronics manufacturer, headquartered in Kadoma, Osaka, Kadoma, Japan. It was founded in 1918 as in Fukushima-ku, Osaka, Fukushima by Kōnosuke Matsushita. The company was incorporated in 1935 and renamed and c ...
), and
Sony
is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (i ...
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.
The ER-4,
introduced by
Toshiba
is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors ...
on December 10, 1955
(or 1956
), was the world's first automatic electric rice cooker for home use. It was developed by Toshiba's Shogo Yamada beginning in 1951 and completed in 1955 thanks to a breakthrough invention by Yoshitada Minami (
ja), president of a Toshiba partner company.
Research and development was a continuous process of trial and error. 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.
The initial launch price was 3,200 yen, about one-third of the average college graduate's starting monthly salary.
At its launch, 700 units were produced, but they did not sell well.
The company then conducted sales promotions using the sales networks of electric power companies, held sales demonstrations, and sold an automatic timer that could turn on the rice cooker at any time, and the product's popularity exploded. By 1960, four years after its introduction, the automatic electric rice cooker was in use in about half of all Japanese households.
The success of Toshiba's automatic electric rice cookers sparked a "manufacturing war", and Matsushita Electric entered the field as early as 1956 with the EC-36. The EC-36 was a cheaper product that used a single pot, reducing the amount of metal used and making it more competitive in terms of sales.
Later, the automatic electric rice cooker was well received in Asian countries and around the world under the name "Automatic Rice Cooker". It also had a great impact on society, giving housewives more time and accelerating the
women's liberation movement
The women's liberation movement (WLM) was a political alignment of women and feminist intellectualism. It emerged in the late 1960s and continued till the 1980s, primarily in the industrialized nations of the Western world, which resulted in g ...
.
On the other hand, Helen Macnaughtan argued that the invention of the automatic electric rice cooker, which freed women from menial tasks in the kitchen and allowed some women to work part-time, was not a great victory for women's liberation because it gave them more time to devote to other household tasks.
Rice cookers made their way to the American market via
Hawaii
Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...
and
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
's Asian demographics in the 1950s, and especially
Louisiana
Louisiana ( ; ; ) is a state in the Deep South and South Central regions of the United States. It borders Texas to the west, Arkansas to the north, and Mississippi to the east. Of the 50 U.S. states, it ranks 31st in area and 25 ...
with the sale of Hitachi models since in the 1970s befitting the prevalence of rice dishes in its
Cajun cuisine
Cajun cuisine ( , ) is a subset of Louisiana Creole cuisine, Louisiana cooking developed by the Cajuns, itself a Louisianan development incorporating elements of Indigenous cuisine of the Americas, Native American, West African, French cuisine, ...
.
In 1972, a rice cooker with a heat-retention function was introduced, and in 1979, an electronic rice cooker equipped with a
microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...
that could also manage the soaking of rice after washing and the heat level. In 1988, rice cookers with electromagnetic
induction heating
Induction heating is the process of heating electrically conductive materials, namely metals or semi-conductors, by electromagnetic induction, through heat transfer passing through an inductor that creates an electromagnetic field within the coi ...
were introduced, which provided higher heating.
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 is a device used for conversion of electric energy into heat, consisting of a heating resistor and accessories. Heat is generated by the passage of electric current through a resistor through a process known as Joule heating. He ...
, 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
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
The boiling point of a liquid varies depending upon the surrounding envi ...
(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
A rice paddle (, Japanese: , ) is a large flat spoon used in East Asian cuisine. It is used to stir and to serve rice, to dip gochujang, and to mix vinegar into the rice for sushi.
Rice paddles are traditionally made from bamboo, wood, or la ...
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
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 completely ...
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 only 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 ...
generally needs longer cooking times than white rice
White rice is milled rice that has had the husk, bran, and germ removed. This alters the flavor, texture and appearance of the seed; helps prevent spoilage (extends its storage life); and makes it easier to digest. After brown rice is milled ...
, 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, soaking 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, fruit, or syrup to make a sweet cereal ...
as an added value. Most can be used as steamers
Steamer may refer to:
Transportation
* Steamboat, smaller, insular boat on lakes and rivers
* Steamship, ocean-faring ship
* Screw steamer, steamboat or ship that uses "screws" (propellers)
* Steam yacht, luxury or commercial yacht
* Paddle st ...
. Some can be used as slow cooker
A slow cooker, (also known as a crock-pot after a trademark owned by Sunbeam Products, but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than ...
s. 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
A slow cooker, (also known as a crock-pot after a trademark owned by Sunbeam Products, but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than ...
, can be used in conjunction with a temperature probe and an external thermostat to cook food at a stable low temperature ("sous-vide
Sous vide (; French for 'under vacuum'), also known as low-temperature, long-time (LTLT) cooking, is a method of cooking invented by the France, French chef Georges Pralus in 1974, in which food is placed in a plastic pouch or a glass jar and coo ...
").
Other uses
Steam rice cookers have been shown to be effective for decontamination of face masks.
See also
* Rice polisher
A rice polisher is a machine for buffing (or "polishing") kernels of rice to change their appearance, taste, and texture or for transforming brown rice into white rice.
Use
Rice polishers are used after the rice has gone through the whitenin ...
* Slow cooker
A slow cooker, (also known as a crock-pot after a trademark owned by Sunbeam Products, but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than ...
* Remoska, small portable oven
* Vacuum flask
A vacuum flask (also known as a Dewar flask, Dewar bottle or thermos) is an insulating storage vessel that slows the speed at which its contents change in temperature. It greatly lengthens the time over which its contents remain hotter or coo ...
* Hot water dispenser
* List of cooking appliances
* List of Japanese cooking utensils
The following items are common Japanese cooking tools used in preparing Japanese cuisine. For a list of general cooking tools see the list of food preparation utensils.
Knives
*'' Deba bōchō'': kitchen carver for meat and fish
*'' Fugu hiki'', ...
References
Further reading
*
{{DEFAULTSORT:Rice Cooker
Rice
Chinese food preparation utensils
Cooking appliances
Cooking vessels
Cookware and bakeware
East Asian food preparation utensils
Japanese food preparation utensils
Japanese inventions
Korean food preparation utensils