Fumiko Minami / Rice Cooker

For 30 years, the best engineers in Japan couldn't solve it. They never thought to ask the person who actually cooked rice.

There's a rice cooker in almost every Asian household I've ever been in. Press a button. Walk away. Perfect rice.

Here's what I didn't know until recently:

For 30 years, the best engineers in Japan couldn't make one that worked.

Mitsubishi tried in 1923. Sony tried in 1945 with a wooden bucket. Panasonic tried. Every prototype needed someone standing there adjusting the temperature. Miss the timing, you get mush. Or burnt crust.

Decades of engineering. Nobody could crack it.

Then a Toshiba salesman did something radical. He asked housewives what their most burdensome task was.

Cooking rice. Up at 5am. Charcoal stove. Three times a day. Two to three hours daily.

Toshiba passed the project to Yoshitada Minami, a small subcontractor who made electric boilers. Business failing. Family home up as collateral.

One problem: Yoshitada had no idea how to cook perfect rice.

So he turned to his wife.

Fumiko Minami cooked rice three times a day for five years. Thousands of batches. She recorded every measurement in her children's school notebooks. She didn't have lab notebooks.

Her logbooks show entries at 2am. At 3am. Cooking through the night.

She tested prototypes on the roof in summer heat. Inside a kotatsu. Outdoors in winter at minus 10 degrees. Her health broke from the testing. When she fell ill, her six children took over, checking thermometers before and after school.

And after 5,000 batches, here's what she found:

You don't need to adjust the heat at all.

Same temperature. Twenty minutes. Perfect rice. Every time.

December 1955. Toshiba ER-4. Within a year: 200,000 units a month. By 1960, half of Japanese homes had one. Today: $5.7 billion global market.

Fumiko wanted to save women time so "they could do something else for three hours a day."

She died in 1959. She was 45. Bedridden at the end, receiving letters from women across Japan thanking her.

Nobody mentioned her name for decades. An academic first documented her role in 2012.

Here's the thing that stays with me:

For three decades, engineers tried to solve the rice cooker from the lab. Nobody thought to hand the problem to the person who actually cooked rice every day.

Fumiko didn't have engineering credentials. She had 5,000 batches and children's notebooks.

Sometimes the answer isn't more expertise. It's asking the person closest to the problem.

Who in your organisation is closest to the problem but furthest from the conversation?