Fields of Arizona Gold: Hayden Flour Mills is on a Mission to Save America’s Heritage Grains From Extinction

A field of wheat ripens under the Arizona sun. Courtesy of Hayden Flour Mills

“My dad and I have one rule: He’s only allowed to tell me one new idea a day”—so Emma Zimmerman begins her book, “The Miller’s Daughter.” Yet it was one of Jeff Zimmerman’s “wild ideas” in 2009 that halted Emma’s doctoral path in neuroethics and set her on the road to what she now calls her dream job: saving near-forgotten heritage and ancient grains from extinction.

At Hayden Flour Mills in Queen Creek, Arizona, the Zimmermans and their team grow and freshly mill storied grains with names like White Sonora wheat, emmer farro, Tibetan purple barley, and Blue Beard durum, and ship them to customers across the country.

“The flavor and color of these grains is the best part,” said Emma. “The grains we grow are all so unique in their aroma; I could probably tell which grain is which by just smelling them.” Whether it’s “light and creamy” White Sonora, “full-bodied” einkorn with its “gentle herbiness and undertones of vanilla,” or “black coffee”-like gazelle rye with “a heady sage and floral aroma,” these are nuances you won’t find in a supermarket bag of industrial white flour.

Emma Zimmerman, co-founder of Hayden Flour Mills, mainly handles the business side of the company, but she still makes time to check on the wheat fields and talk with the farmers— sometimes with her family in tow. David Alvarado

But in a modern world desiring familiar, fast, and cheap, making these old, obscure grains commercially viable is no small feat. They spent years researching and learning, often by trial and error, every step of the process.

Instead of a dissertation, Emma ended up writing a cookbook (“​​An equally big undertaking,” she said) about why these grains matter—and, of course, how to cook and bake with them.

Seeds of an Idea

Raised on a North Dakota farm, Jeff Zimmerman, like many farmers in the latter 20th century, witnessed the industrialization of wheat farming. He watched the wheat on his family farm diminish in height and quality with the introduction of new seed varieties during the Green Revolution of the 1960s, bred for higher yield and faster profits—at the cost of crop resilience, flavor, and nutritional value.

To keep up with competition, farmers were pushed to scale up, move toward planting monocultures (single-variety fields), and rely on fertilizers and pesticides. Meanwhile, small mills were overtaken by industrial roller mills, which efficiently processed this supply into perfectly white, uniform, and infinitely shelf-stable flours.

Years later, living in Tempe, Arizona, Jeff told Emma about his “wild idea.” He wanted to revive the forgotten tradition of one of those defunct small mills, Tempe’s own Hayden Flour Mills, a fixture for local farmers since its founding by Charles Hayden in 1874 until it closed in 1998.

Each of Hayden’s heritage flours and grains—from red fife wheat, to purple barley, to blue beard durum—has its own distinct character. David Alvarado

Jeff had discovered the incredible difference that using freshly milled flour made in his home-baked bread. An avid reader and researcher, he started milling his own with a small tabletop mill in their garage, and he caught the interest of an award-winning Phoenix chef, Chris Bianco.

On August 13, 2011, Emma and Jeff moved a 32-inch stone mill they ordered from Austria into the back of one of Bianco’s restaurants. Hayden Flour Mills, a tribute to the original historic mill, was born.

From Field to Flour

“Stone-milling is a very simple, old technology of splitting open the wheat berry between two coarse stones,” Emma explained. The resulting whole-grain flour contains all three parts of the grain: the outer bran, the endosperm, and the germ (which Emma calls the “real flavor powerhouse of the grain”). Even after sifting, specks of the bran and germ remain. In contrast to modern roller mills, which efficiently separate and discard the bran and germ—and much of the grain’s fiber, protein, and important vitamins and minerals—this slower, simpler process preserves the whole grain’s natural oils, nutrients, and unique flavors.

The flour has “a great feel, too,” Emma added. “Stone-milled flour is very silky and soft, and it’s kind of addicting to run your hands through it.”

Emma calls her dad, Jeff, “the brains behind the mill.” Though not a farmer, he grew up on a North Dakota farm and later discovered the joys of freshly milled flour through his bread-baking hobby. Courtesy of Hayden Flour Mills

To match the heritage of their namesake and milling methods, the Zimmermans set out to find wheat varieties grown before the industrialization of agriculture: heritage grains, defined as varieties that existed before the 1960s, and ancient grains, ones that date back thousands of years.

They began with White Sonora. This nearly lost heritage wheat “has a long history in the Southwest,” Emma said. The first wheat to arrive in North America, brought by European missionaries in the 1600s, it was grown throughout northern Mexico and the American Southwest for hundreds of years, adapting to the arid climate and giving rise to regional specialties like the Sonoran flour tortilla. “So bringing it back has also been about reviving the food traditions around a Southwestern wheat,” Emma said.

With the help of Native Seeds/SEARCH, a Southern Arizona seed bank, the Zimmermans procured 1,000 pounds of White Sonora seeds. A farmer friend of Jeff’s, Steve Sossaman, agreed to plant the seeds on 10 acres of his farm in nearby Queen Creek to determine the quality of the potential harvest.

“Later that summer … I walked into the field and gathered up a large bundle of this golden bounty,” Emma wrote in her book. “That bundle would become my wedding bouquet five months later, and this intoxicating wheat would define the next decade of my life.”

Emma and Jeff Zimmerman fill the mill with einkorn to make flour. The stone is encased by the white metal cover. David Alvarado

Growing Grains

Since then, Hayden has expanded that first 10 acres into 400. They moved into a larger mill located on Sossaman’s farm, where much of their wheat is still grown, and where they still stone-mill all their grains in small batches.

White Sonora wheat remains a best-selling staple, due to its disease-resistant, drought-tolerant nature, and its versatility. Whole berries can be boiled and added to grain bowls, salads, and soups, and the flour is ideal for baking breads and sweets, or blending with semolina to make homemade pasta.

Einkorn, which the company calls “the great-grandparent of modern wheat,” has become one of Emma’s favorite grains, along with farro. “I could eat a farro salad every day, and anything baked with einkorn flour is just so flavorful,” she said. “These two grains are just so nourishing.”

Along with a variety of wheats, other Hayden grains include bronze and purple barley, gazelle rye, oats, and non-GMO corn. They also mill chickpeas into a high-protein, gluten-free flour.

Emma said her father’s zeal for ancient grains remains unbounded. His passion lies in “researching new grain varieties and tracking down seeds,” she said, which “includes a lot of Googling, talking to other millers, and reading books. The millers and ancient grain communities are very generous with their knowledge.”

Emma enjoys checking on their fields and experimenting with recipes, but her primary role at Hayden is handling business aspects and working with their “team” of six that has become “really more like family,” she said.

White Sonora wheat products, made from a heritage variety with a long history in the American Southwest, are among the company’s best sellers. Courtesy of Hayden Flour Mills

Courtesy of Hayden Flour Mills

Sharing the Harvest

Emma and her team are passionate about educating their community, and beyond, about the importance of reviving and preserving these old grains, and locally growing and milling them.

“Our food system has slowly become less and less diverse, even though we have more and more choices at the grocery store,” Emma said. “We hope we can make a small dent in reversing our loss of biodiversity by bringing back some of these heritage grains in a fun and accessible way.

“It’s been even more apparent in the last few years how important resilient local supply chains are,” she added. “Because we’re vertically integrated, we’re able to weather disruptions in grain supply.”

Emma pointed out that people are increasingly interested in knowing exactly where their food comes from. When the pandemic hit, their tours of the mill shifted to virtual-only, but Emma said the plan is to one day get back to in-person education.

“The Miller’s Daughter” by Emma Zimmerman (Hardie Grant Books, 2022). David Alvarado

“Seeing where your food comes from and how it’s made is so important,” she said, “and our mill is located on the farm where we grow some of our wheat, so the connection between field and flour is so easy to visualize.”

For now, curious consumers can learn from the wealth of information on Hayden’s website—and now in Emma’s book. Readers will find guides to different grains, essential cooking tips, and recipes from einkorn ravioli to rye-honey cake.

One popular and easy recipe is Emma’s chickpea flour chocolate chip cookies, which combine the buttery, nutrient-dense flour with tahini. “They’re like a grown-up peanut butter cookie, and no one can ever guess they’re made with chickpea flour,” Emma said.

“I so desperately want people just to give these grains a taste,” she said, “because I know once people try them, the difference is so clear … I can stop talking and trying to convince them.”

This article was originally published in American Essence magazine.