Feb 11, 2016 • By

How a ‘wandering engineer’ helped create one of our greatest inventions

The “middlings purifier” is one of the most important inventions in General Mills history. It helped transform the Washburn Crosby Company – the forerunner of General Mills – into a leading flour company in the world.

But the story behind its development is perhaps even more intriguing. It began with the hiring in 1869 of George H. Christian, who William D. Washburn (the brother of company founder, Cadwallader) called “the best operator in the state.”

Christian grew up in rural Alabama with little formal education but did have an influential tutor – a “frail eccentric known only as ‘the ghost’” who inspired him to pursue “occupations of the mind.”


Christian taught himself French, German, Italian and a bit of Greek, as well as the organ. Once he began running Washburn’s mill, he focused on a problem that was vexing millers throughout the Upper Midwest: how to make flour from hard spring wheat instead of winter wheat.

Due to the shorter growing season, farmers in the Upper Midwest grew primarily hard red spring wheat. The winter wheat grown in Kansas and Oklahoma milled more easily into whiter flour, but it wouldn’t grow in northern regions.

The milling process tended to fracture the darker-colored bran in the harder kernel spring wheat, resulting in a less attractive grayish-looking flour. It made fine bread, but it was less attractive – and flour from winter wheat mills was preferred by consumers.


Christian visited several Minnesota mills that had had some success milling spring wheat, including one that produced flour bakers called “the doctor” because “when blended with other flours, it seemed to cure any ills.”

“Christian, who liked nothing better than experimentation, set out to develop such a doctor of his own,” wrote author James Gray in “Business Without Boundary: The Story of General Mills.”

By chance he ran into a “wandering engineer,” Edmond La Croix, who had come to Minneapolis from Montreal with his brother. They were educated in France and had experimented with a device that later came to be known as the “middlings purifier.”

“His model, produced in great secrecy behind locked doors, was, as Christian reported later, ‘a small crudely built arrangement of moving sieves.” It didn’t work perfectly and had “good and evil moods,” according to Christian.

Using this new process – and LaCroix’s new machine – Christian could produce higher quality “patent flour” that was soon fetching between $4 and $4.50 more per barrel than flour from winter wheat. Other nearby mills, including Charles Pillsbury’s mill across the Mississippi River, acquired the technology – and the rest of the story, as they say, is history.

The fledgling milling industry grew dramatically. The Upper Midwest opened to farming and agriculture, including the bonanza farms of the Dakotas, growing hard red spring wheat. Railroads and railroad tycoons like James J. Hill followed and began shipping wheat to the Minneapolis mills, and the millers’ flour to population centers in the East.

Minneapolis became known as the “Mill City” – producing more flour than anywhere else in the world for the next 50 years.

The growth of the food industry followed, including companies like Pillsbury, Malt O’ Meal, Cream of Wheat, Hormel and more. And an entire region was born.

History, of course, does have a way of repeating itself. It’s too early to tell whether the process developed recently to create gluten-free Cheerios – which also uses a series of sieves to purify oat flour – will create a revolution in the cereal aisle.

Editor’s note: In 2016, General Mills is celebrating its 150th anniversary. This story is part of a year-long series on “A Taste of General Mills” to highlight the people, products and projects that have contributed to the company’s legacy. Discover more about our past on GeneralMills.com and GeneralMillsHistory.com. If you have a question about our history, or would like to donate an item to the company archives, send our Archives team an email at ask.thearchivist@genmills.com.

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