What You Need to Know
During heating, water penetrates the semi‑crystalline starch granules, disrupting hydrogen bonds and causing amylose to leach and amylopectin to swell. The resulting gelatinised starch network traps fat and air, giving pastry its characteristic flakiness and crumb structure. The process is modulated by moisture, fat coverage, pH, and baking time, which shift the onset and completion temperatures.
The Science
Primary Reaction
Hydration and swelling of starch granules leading to gelatinisation