A rice cooker or rice steamer is a kitchen appliance used to automate and simplify the process of cooking rice. Traditionally, rice is cooked by measuring a specific amount of rice and water and applying heat for a specific amount of time. The process is deceptively simple. Rice cookers provide a simple alternative. Although rice cookers do not necessarily speed the cooking process, the consumer's involvement in cooking rice with a rice cooker is significantly reduced and simplified.
With a rice cooker, the cook combines a predetermined amount of rice and water inside the rice cooker and turns the device on. The rice cooker heats the water-rice mixture until all the water has either evaporated or is absorbed by the rice. This works on the principle that the boiling water maintains a constant temperature (212 °F or 100 °C at sea-level). Once the temperature changes, the device shuts off or switches to warm to keep the rice ready to serve for up to several hours. A rice cooker makes it virtually impossible to end up with scorched rice on the bottom of the pan.
Basic "on—off" or "on—keep warm" rice cookers can double as electric steamers for other foods. Many include a steamer tray. They can be used just for steaming, or to steam food while preparing rice. Creative cooks prepare grains other than rice by adjusting the amount of water added prior to cooking.
Newer, "fuzzy logic" rice cookers have several settings for different types of cooking. Most commonly, these include a basic rice setting, a brown rice setting, a quick cooking setting, and a porridge setting, although different brands may include more or fewer options. These cookers can also be used to prepare risottos, pilafs, and rice puddings. However, most fuzzy logic rice cookers can not be used as steamers.
Rice cookers commonly come with a special cup to measure 180 ml, or about 6 oz of rice. It is important to note that a rice cooker that has water level markings on the side of the bowl will be for rice measured in this cup, not a standard measuring cup.
The rice cooker is considered an important part of modern Japanese cooking.