In 2009, Don Guerra was a grade-school teacher with a yearning for bread. He had previously given up the baking life for grad school. But almost a decade into his teaching career, Guerra found himself longing for the feeling of dough in his hands. So he did what many a fledgling founder does: He set up shop in his garage.

His first customers and supporters were his neighbors. It’s this rootedness in community that motivated Guerra to name his bakery Barrio, after the Spanish word for “neighborhood.” Like the bakery’s origins, Guerra’s ingredients are literally rooted in the community. While his lineup includes traditional European loaves familiar to Great British Bake Off fans, such as olive fougasse, the grains he uses are largely local, either wheats that have learned to thrive in the arid Arizona desert after centuries of adaptation, or native plants.

Guerra’s most famous loaves are evidence of this fusion. His Saturday morning Barrio Mesquite loaf, made with wheat and mesquite flour, bears the spicy taste of the desert. His Pan de Kino, meanwhile, is made with White Sonora, a desert-adapted heritage wheat introduced to southern Arizona in the late 1600s by a Spanish missionary, which is grown especially for Barrio by a local farm. Most iconic among his offerings is the Heritage loaf, distinguished by its blend of native desert grains and the signature stenciled-in saguaro that decorates it. The local environment even plays a key role in the baking process, literally causing Barrio’s breads to rise: They are made not from commercial yeast, but from “natural leavening,” or a sourdough starter, whose fermentation incorporates ambient yeast and bacteria.

Guerra’s commitment to all things local hasn’t stopped him from receiving national recognition, however. In 2019, he was a semifinalist for the Outstanding Baker James Beard award, the Oscar of bread. But more than any award, the proof is in the pudding—or in the Desert Durum loaf. Venture to Barrio Bread on a weekend morning, and you’ll see a line of locals snaking around the corner of his shop, each hungry aspirant waiting for a crusty, earthy slice of Tucson.