SONOMA, CALIF. — The Bread Bakers Guild of America will sponsor a tour of Heartland Mill, an organic flour mill in Marienthal, Kas., on April 26. The tour will educate bakers on how wheat varieties are selected and bred and how wheat is processed into flour.

As part of the tour, participants will have the opportunity to walk through the mill and visit the quality control laboratory. In addition, they will watch demonstrations of the Alveograph and other apparatus, as well as learn how to interpret test results and apply knowledge in the bakery.

Thom Leonard, a founding partner of WheatFields Bakery Café in Lawrence, Kas., and Mark Nightengale, co-founder and general manager of Heartland Mill, will lead the tour.

Mr. Leonard is a former board member of the Bread Bakers Guild of America and since 2001 has helped Heartland Mill with quality assurance and the development of flour suited for making hearth-baked bread.

In 1995, he founded the Grain Exchange, a grass-roots effort to enhance genetic diversity in traditional cereal crops, and in 2009 he co-founded the Heritage Grain and Seed Co. to promote the growing and use of landrace and traditional grain crops.

“I’m excited about being able to share with fellow bakers some of what I love about western Kansas — the uninterrupted views to the horizon in all directions, shortgrass prairie, grazing bison and pronghorn, the distant grain elevators marking the next town, 10 or 15 miles down the road,” Mr. Leonard said. “This is a great opportunity for bakers to learn more about their single most important ingredient, and there’s no better place to get it than the High Plains of western Kansas.”

In addition to the tours, the all-day event will include presentations from Richard S. Little and P. Stephen Baenziger. Both Mr. Little and Mr. Baenziger are with the organic wheat-breeding program at the University of Nebraska.

The Kansas Mill and Farm Tour is the first of three mill tours taking place around the United States this year as part of The Guild’s World’s Fair of Breads 2010.

Registration for the event is $150, with a deadline of April 12 to sign up. For more information visit www.bbga.org or call (707) 935-1468.