Past Forward: The Automatic Rice Cooker's Unlikely Inventor

Abstract

It isn't often that housewives get credit in the annals of invention, but Fumiko Minami earned her place by helping her husband, Yoshitada, invent the first automatic rice cooker. Yoshitada operated a small factory that made electric water heaters for Toshiba, and so he understood the basic principles involved in controlling temperatures. But it was Fumiko who spent five years researching and testing the perfect recipe for rice. She found the key to automating the rice-cooking process was to turn off the cooker after exactly 20 minutes of boiling. Toshiba engineers eventually landed on a bimetallic switch that bent and cut the circuit when the cooker's internal temperature surpassed 100°C. Toshiba began selling the ER-4 denki-gama (electric pot) in December 1955. It was priced at a steep 3,200 yen-one third the average monthly salary in Japan at the time-and yet within the first year, the company was producing 200,000 rice cookers a month. Today, the worldwide annual market for rice cookers is nearly US $3 billion.