Starch retrogradation and stale breadStarch retrogradation is the recrystallisation of gelatinised starch molecules during cooling and storage; it's the primary cause of bread becoming stale. After baking, amylose and amylopectin chains realign into ordered structures, expelling bound water and causing crumb firming and loss of perceived freshness even when microbial spoilage is absent. The rate and extent depend on starch composition, moisture level, storage temperature and