Designing the First Ever Mobile Grain Mill

Rendering of the Mobile Mill interior (Kuth Ranieri Architects)

Sayra Trejo

Grain mills seem to be just a remnant of the past, a reminder of the way things used to be done. The cumbersome equipment used to turn wheat berries into flour has been virtually forgotten, until recently. The non-profit organization, Honoré Farm and Mill, based in Marin County, California, worked with Kuth Ranieri Architects to envision the country’s first-ever mobile wheat and grain mill.

Using the Mobile Mill, Honoré founder and president, Elizabeth DeRuff and oversight manager Adam Willner are sowing the seeds, literally, to change how we interact with the flour we bake with and the bread we eat.

Since the inception of her idea to bring a mill to the masses, and continuing with a successful Kickstarter fundraiser in 2016, DeRuff developed the Honoré Mobile Mill. She tapped Willner, a food and beverage consultant to head up the Mobile Mill operations.

KR previously partnered with DeRuff on the Larkspur Farm project, a land stewardship endeavor that aimed to establish an urban farm and community center in Marin County. Unfortunately, the property was sold to a residential developer, but the partnership sprouted a new idea, which eventually blossomed into Honoré and what would become the Mobile Mill.

Rendering of Larkspur Farm (Kuth Ranieri Architects/DGDA and Roth LaMotte Landscape Architecture)

“DeRuff  and Kuth Ranieri share a commitment to ecology, food and education.”

-Liz Ranieri, Kuth Ranieri Architects Design Principal.


As the design arm for Mobile Mill, Kuth Ranieri Architects focused on the Mobile Mill’s concept design, form, constructability and wood interior.

Early sketch of the Mobile Mill (Kuth Ranieri Architects)

Besides aesthetics, Honoré needed something functional to secure the heavy stone mill and safely transport it. Through trial and error, the non-profit was able to find the right person to handle building the structure—Brian Sullivan. The East Bay-based builder was able to successfully put the Mobile Mill together, given his experience building unconventional vehicles for Burning Man.

Putting the Mobile Mill frame together in Sullivan’s Emeryville, CA warehouse (Kuth Ranieri Architects)

The Mobile Mill on display in Healdsburg (Sayra Trejo)

The custom-made, 700 lb. mill is situated inside a minimalist aluminum trailer, marked with the black Honoré logo. Overall, the design was “inspired by a shed typology, a simple wood-frame form full of natural light, familiar to the agrarian American landscape,” said Ranieri.

Mobile Mill aluminum exterior (Honoré Farm and Mill)

Incorporating the agrarian scheme into the design was a nod to traditional milling. At one point there were approximately 23,000 community mills scattered across the United States, but this is no longer the case.

When Elizabeth founded Honoré, she realized that the closest mill was 100 miles away from her in Ukiah, CA—and the mill was stationary. While freshly milled flour has a shorter shelf life than conventional white flour, it preserves more of the grain’s nutritional properties.

Locally-grown wheat (Sayra Trejo)

Essentially, the traveling mill serves as an educational tool, and allows people to see the flour-making process first-hand. This summer, the Mobile Mill embarked on its maiden 3,400-mile voyage to Austin, TX., for the Episcopal Church National conference.

Honoré’s educational goals stem from DeRuff’s desire to make heirloom wheat and flour more readily available, just as locally-grown tomatoes and berries have become easy to find in farmer’s markets across the country. The Mobile Mill is aiming to pave accessibility to heirloom grains and flour.

Throughout history, the process of transforming wheat into flour remained virtually unchanged for roughly 5,000 years, until industrialized processes entered the equation in the late 19th century.

What was previously an amalgam of different local milling systems, gradually centralized into one, industrial wheat economy. Small grain farmers were pushed out and flour and bread-making became increasingly mechanized. Currently, the industry is monopolized by three major flour millers.

In the United States, Midwest granaries dominate wheat production, and it’s no secret why. In the same amount of time it takes a farmer to harvest 50 pounds of grain, an industrial-grade combine can harvest almost 2,000 pounds from a massive wheat field.

Honoré wants to develop a robust platform to incorporate small local farmers, millers, bakers and churches (churches need flour for communion bread) into local milling economies by creating connected networks, known as Grower’s Guilds.

So far, Honoré Grower’s Guilds have been established in parts of California and Michigan. They have also started planting wheat in a growing number of locations, by drawing on Elizabeth’s connection as an agricultural chaplain with the Episcopal Church.

Like David up against an industrial-grain-Goliath, Honoré aims to reintroduce heirloom grains to counter ubiquitous highly processed white flour. The heirloom grains are not heavily processed, or genetically modified.

Freshly ground Sonora flour (Sayra Trejo)

To help fund its educational endeavors and management, Honoré has started selling flour milled by the Mobile Mill as well as their shortbread cookies. The buttery round cookies, stamped with the Honoré logo have created an accessible, tangible product–but for the small non-profit, they’re also quite labor intensive.

Honoré Farm and Mill shortbread cookies (Sayra Trejo)

A volunteer measures flour (Sayra Trejo)

On a warm October morning, a group of four volunteers gathered at St. John’s Episcopal Church in Marin County to help bake shortbread cookies. The next day, the Mobile Mill took its first Bay Area voyage to the Women and Bread event at Healdsburg SHED, where the cookies packed in rustic mason jars are sold.

Mixing the shortbread cookie dough (Sayra Trejo)

Unbaked shortbread cookies (Sayra Trejo)

A volunteer scrapes down a mixer while baking shortbread (Sayra Trejo)

Packaging the shortbread cookies (Sayra Trejo)

While industrialized agriculture has created mechanized models and uniformity in bread making—which has aided its mass production—DeRuff is reinforcing the concept of true artisanal baking.

Rendering of the Mobile Mill (Kuth Ranieri Architects)

Ultimately, KR’s goal for the Mobile Mill was for its dedicated use, form and function to translate into an elegant and distinctive design that would become a symbol for a renewed way of living responsibly with the land.

For Elizabeth and Honoré, the project means helping others reconnect with the art of agriculture and recognizing it as a living system—and she’s doing it with her Mobile Mill in tow.


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