This sourdough history comes from our wonderful bread instructor, Joan Kirschner, who teaches a 3-week sourdough series each term. What is sourdough?Sourdough refers both to bread, and to the starter used to make it. Starter begins with a combination of flour and liquid. When flour is mixed with liquid, the friendly bacteria (lactobacilli) and wild yeast in both the flour and your surrounding environment start working together. Within their flour-and-water slurry (now called starter), these tiny living creatures generate byproducts that cause bread to rise and give it complex, rich flavor. How does sourdough make things rise?A packet of yeast makes dinner rolls rise....