CASTLE ROCK - The farmers got off the yellow school bus and walked into the field of waist-high Kernza, a perennial wheatgrass that someday could undergird breads to beers across the nation.

One field-walker wears a "You had me at deep roots" T-shirt and another points out elderberries in a ditch.

Passerby could mistake the waves of Kernza for a bluestem prairie, save those small, but powerful kernels of grain.

With a deep root system and low carbon footprint, Kernza could be a food staple of the future, helping an agricultural world toiling under smoky skies, dire water levels and eroding soil.

But the task is now getting others to buy in.

There are trailblazing farmers, like those who attended last month's Kernza-Con conference at a hotel near the University of Minnesota, and innovative food and beverage makers, like Minneapolis-based Tattersall Distilling that unveiled a Kernza-inspired whiskey earlier this year.

It will take many more growers and end users, though, to scale up the grain.

"Profit is a secondary consideration right now," Kurt Kimber told a group of growers and educators in a shed on his farm in Dakota County, which served as a tour site during Kernza-Con.

Kimber, a self-described radical who lives in Minneapolis but oversees a farm across a gravel road from his childhood home, planted Kernza and believes in its future. "What the [Kernza] community is doing right now is the flat part of the growth curve."

For now, they're making sure the grain is ready to go when, hopefully, buyers come knocking on doors.

Extension agents, researchers and farmers attended the conference, sponsored by KernzaCAP, Green Lands Blue Waters, and the U of M's Forever Green Initiative, to learn all-things Kernza — from drought tolerance to manure applications.

"We've been working with it for many years, and it's still fascinating — with all the benefits that come from a perennial," said Per-Olof Lundquist with the Swedish University of Agricultural Sciences in Uppsala, who'd come for the conference. Swedish food manufacturers' experiments with Kernza in pizza dough and other bread products are only the beginning, he predicted. "I guess, beer would be great."

The enthusiasm, supporters acknowledge, may outpace the commercial reality at the moment. In 2019, General Mills' organic brand Cascadian Farms had hopes for a Kernza cereal that were dashed after a crop fail. In January of 2022, researchers cast doubts on the intermediate wheatgrass' meager yields, suggesting replacing traditional bread grains would take more acres than currently planted with wheat.

But supporters say it's too early to count Kernza out.

This spring, the Minnesota Legislature approved more than $6 million in Clean Water Funds for Forever Green, which stewards perennial grains, including Kernza. They also earmarked $500,000 for a Minnesota Department of Agriculture grant program for cover crops such as Kernza.

Meanwhile, products — from pancake mixes to Patagonia-collaboration beers — keep popping up.

On a recent weekday at Tattersall's River Falls, Wis., distillery in a reconverted Shopko, distillery manager Bentley Gillman spoke like a soil scientist as he explained what excited him about the casks filled with aging whiskey derived from the wheatgrass.

"How much on inputs am I going to save over its life cycle?" Gillman said. "Can we keep all that soil up here instead of sending it down the river into the dead zones in the Gulf of Mexico?"

Launching an earth-friendly grain — like debuting an electric vehicle or opening up a vegan butchery — can attract skeptics. Minnesota's infrastructure for growing and marketing wheat, corn and soybeans literally snakes across the state, from the Red River Valley to the Duluth port to the barges along the Mississippi River.

Kernza has an uphill climb. The kernels are smaller than a typical wheat variety. It can be fickle the first year. And it's not a cash crop marketed at the local elevator. Largely, the producers on Minnesota's vast farmlands will continue planting traditional row crops — used in fuels and animal feed — for years to come.

But the bulb of ingenuity has intrigued some farmers, even if they know they're early adopters.

"There's some challenges getting things into the supply chains at a scale that we need to sort of match supply and demand," Ben Penner, a St. Peter farmer and vice president of the Perennial Promise Growers Cooperative, said as he boarded a bus after touring Kimber's Kernza plot recently. "But for what I can do as a farmer, it's the most direct way to address climate change."

An earlier version of this story misstated Kernza-Con's event sponsor.