ANN ARBOR, MICH. — Doing business in the nation’s second most diverse agricultural state (Michigan grows 300 different commodities on 9.9 million acres and 51,600 farms statewide) has proved highly beneficial to the cause of Zingerman’s Bakehouse, which was founded in 1992 and is part of the innovative Zingerman’s Community of Businesses

“The last few years we have been bringing in local grains from Michigan farmers near Traverse City,” said Frank Carollo, managing partner at Zingerman’s Bakehouse. “It’s a little microclimate that’s similar to Vermont and Oregon. We’re getting hard red spring wheat with high extraction. We are buying the wheat berries and milling them daily and injecting freshly milled flour into all sorts of recipes.”

In October 2018, Zingerman’s purchased a 26-inch stone mill from New American Stone Mills in Vermont.

“The new breads we are creating are made with freshly milled whole grains and typically a combination of them,” Mr. Carollo said. “They are not all 100% freshly milled but that’s where we are going. We don’t want to diminish what we’ve done in the past 25 years. But more and more new things will be featuring a combination of local grains and freshly milled flours.”

With excitement, he mentions the fougasse they now make with freekeh, Michigan spelt and Warthog grown in Illinois.

“We make a porridge, and that’s a super delicious bread,” he said.

A farmer near Saline is planting 15 acres of Warthog wheat for Zingerman’s, which is building a network with local farmers and getting to know who’s doing what.

“The more we dig, the more we find out things going on out there,” Mr. Carollo said. “The network is growing and expanding the more we poke around. Whenever we start something new, we typically have humble expectations. It usually takes three years before we reach what we expect. But what is happening now leads me to being more excited and energized than ever.”

Already for some pastries, the Bakehouse is substituting whole wheat flour for all-purpose flour. They make scones with freshly milled einkorn, “that’s out of this world.” Zingerman’s switched in freshly milled Michigan grown soft white wheat flour in their famous Funky Chunky Dark Chocolate cookies.

“With the cookie, we didn’t change a thing but the flour, and nobody has said a thing,” he said. “We have found better texture, better finish and a cookie that retains moisture better.”

For Zingerman’s popular shortcake biscuits, bakers substitute in freshly milled soft white wheat flour, with a little more buttermilk and leavening to lighten the finished product a bit. Carrot cake is next.

For the future, Mr. Carollo said rather than just one 26-inch mill, they might have an entire room with a couple of stone mills.

“Maybe our mix is no longer 90% white flour but becomes 70%, and we’re milling a lot more on site,” he said.

Currently, he says, the Bakehouse uses 1.5 million to 2 million lbs of white flour a year.

“We’re milling no more than 150 lbs of flour a week,” he said. “It’s a humble start.”

A large amount is used for production of Zingerman’s rye bread, Roadhouse bread and country miche. Their volkornbrot (German whole grain seed bread) is now made with 100% freshly milled flour.

“Specialty grains and freshly milled flours — it’s an injection of flavor and nutrition,” Mr. Carollo said. “It’s the fermentation that makes it special. We’ve built a strong reputation, so our customers trust us. We work hard to let people know we care about what they think.”

In 1992, longtime friends Mr. Carollo and Zingerman’s Delicatessen founders Paul Saginaw and Ari Weinzweig opened Zingerman’s Bakehouse. Mr. Carollo originally met Mr. Saginaw and Mr. Weinzweig when they worked together in a restaurant in 1978 and after partnering with Mr. Saginaw at Monahan’s Seafood Market for seven years, he became the managing partner of the Bakehouse when it opened.

“For 41 years we’ve been working together,” Mr. Carollo said, “but now we need to find the next generation to make sure we continue to connect with customers. We need to reach and connect with our younger customers.”

Amy Emberling is co-managing partner of the Bakehouse, which started as a simple bread bakery with a single customer, Zingerman’s Delicatessen. Driven by passion for baking great bread and pastries and to share, the business has grown and evolved. Today the Bakehouse serves Zingerman’s partner businesses, the southeastern Michigan community, and beyond.

The commitment revolves around using the best ingredients they can find, including organic wheat flour, rye, and cornmeal and Michigan-grown grains like spelt and einkorn. The bakers aim to showcase the flavors and benefits of enjoying whole grains and highlight the spectrum of wheat varieties available.

The Bakehouse considers time a key ingredient in baking. Allowing the fermentation to work its magic in naturally leavened bread is how they develop maximum flavor. But it requires patience and determination. The naturally leavened bread takes anywhere from 18 to 28 hours to produce.

Mr. Carollo has been training, coaching and teaching for nearly 30 years. Through BAKE!, the hands-on teaching bakery tucked beween Zingerman’s Bakehouse and Zingerman’s Creamery, he coaches the fundamentals of baking, helping both novices and experts.

Ms. Emberling has been an avid food lover and baker since her childhood in Nova Scotia, Canada. After high school she moved to Cambridge, Mass., and received her bachelor’s degree from Harvard College. She then followed her passion for food and learned to cook and bake at L’ecole de Gastronomie Francaise at the Ritz Hotel in Paris, as well as in Michigan restaurants. In 1999 she received her master’s degree in business administration from Columbia University. She came to Zingerman’s Bakehouse when it opened in 1992 as one of the original bakers on the staff of eight. She soon became the first manager of the bread department, and in 2000 she became a partner. As well as teaching at BAKE!, Ms. Emberling presents for ZingTrain on the company’s business practices. A few of the Bakehouse items she is personally responsible for developing are the Old School Apple Pie, Buenos Aires Brownies and Gingerbread Coffeecake.