Tracing The History Of The Rice Cooker
The idea of using electricity to cook rice is not new. The Japanese Imperial Army in 1937 equipped its’ Automobile-kitchen with primitive rice cooking boxes. This was a rectangular wooden rice cooking box which had two electrodes attached to each end. To cook rice, the box was filled with washed rice and water. Turning on the current caused the water to boil. Once the rice is cooked, the absence of water caused resistance and reduced the heat. This method, however was not entirely satisfactory and also carried a large risk of electrocution, making it clearly unsuitable for home cooking.
Mitsubishi of Japan was the first to produce a commercially available electric rice cooker in 1945. The Mitsubishi rice cooker was an aluminum pot with a heating coil inside. It had no automatic turn-off, and required constant monitoring while cooking rice. Since their introduction, Japanese rice cookers have continued to dominate the rice cooker market.
The early electric home rice cookers used the basic concept of simply heating the rice to cook and turning off the heater when the temperature rose beyond a certain point. This method was imperfect, influenced by seasonal changes in room temperature and often produced under-cooked rice. Companies continued to experience failures in their trial-error approaches. One company even produced a prototype model that had embedded heating elements in a traditional wooden rice container.
The first commercially viable rice cooker was invented by Yoshitada Minami for Toshiba. In 1956, the Toshiba placed it on the market. Rice was put into the aluminum pot, and water into a surrounding container. When the water in the outer pot boiled off, the temperature of the pot rose rapidly. A bimetallic thermostat then activated, and automatically turned off the cooker. Soon, Toshiba was producing 200,000 rice cookers per month for the Japanese rice cooker market. Only four years later, rice cookers could be found in half of Japanese homes.
The original basic design was gradually phased out during the 1960s. Today, more efficient rice cookers have an insulated outer container and an inner removable pot, usually coated with a teflon non-stick surface, and stamped with water-level graduations marked in cups of rice used.
The first models did not have a keep-warm feature and the cooked rice cooled too quickly, thus it was often necessary to move the cooked rice to insulated serving containers. In 1965, Zojirushi Thermos company started selling electric Zojirushi rice cookers with a stay-warm function. The product sold two million units per year. Other manufacturers soon followed suit. The stay-warm function can typically keep rice warm for up to 24 hours. This not only keeps the rice at the desired temperature, it also has the benefit of suppressing growth of Bacillus cereus that is a cause of food poisoning. Another notable improvement was the use of electric timers.
In simple models, a mechanical thermostat is used to turn off the cooker when the water has boiled off. Since the 1980s, higher-end electric rice cookers use microprocessors to control the cooking process, often incorporating a battery-powered memory and electronic timer that can be used to set the desired “ready time”. Since 1990s, many models allow users to select desired cooking results with a variety of settings for different types of rice, other grains or even cakes and breads. Most models can be also used as steamers and typically come with a steamer basket.
In the late 1980s, some high end electric rice cookers started using induction heating. This produces tastier cooked rice by controlling the heating process more precisely. Expensive models often provide steam-heating function.
In the 2000s, more deluxe models appeared on the market and attracted much attention. These models are characterized with non-metallic materials for inner cooking bowls to employ the thermal far-infrared waves in order to improve the taste of cooked rice. In 2006, Mitsubishi produced the most expensive rice cooker to date which has an inner cooking pot called made of a single piece of hand-carved pure carbon. It has a better heat generating profile with induction cooking. Despite the high price of over $1,400, it sold 10,000 units within 6 months of being introduced. This set the trend for extremely high-end models in the market. Rice cookers are now available with rice bowls of pure copper, ceramic-iron layers and even diamond-coating.
Japanese rice cookers such as Zojirushi rice cookers, Sanyo rice cookers and Panasonic rice cookers continue to dominate the marketplace although they face some competition from Korean and American brands.
For more information on rice cookers: their history, how they work, how they are produced etc. visit Rice Cookers.