What You Need to Know
The high temperature drives the Maillard reaction, forming melanoidins that give the crust its color and flavor, while the sourdough starter lowers dough pH to 4.5–5.0, promoting lactic acid fermentation that produces lactic acid, ethanol, and CO₂. The acidic environment also inhibits spoilage microorganisms, extending shelf life.
The Science
Primary Reaction
Starch gelatinization and Maillard browning; lactic acid fermentation