Why Pastry Shrinks

Why Pastry Shrinks: The Critical Importance of Resting. 

When judges said pastry has shrunk so that means it needed a bit more resting and if it isn't rested and chilled that's what happens it all slips in, they were explaining a fundamental pastry principle. Pastry shrinkage occurs because gluten strands develop when flour mixes with water and gets worked during rolling. These gluten proteins act like rubber bands - they tighten and contract when exposed to oven heat. Resting dough in the refrigerator for at least 1 hour (preferably 2 hours) allows gluten to relax, preventing dramatic shrinkage during baking. The cold also firms up butter so it doesn't melt prematurely. Without proper resting, pastry pulls away from pie dish sides and sinks - it all slips in as judges described. Rest dough twice: once after mixing and again after rolling into the pie dish. Competition pressure may have caused Rob to rush this step despite his usual casual expertise making pies while other people around having a drink. Professional bakers always work ahead to ensure proper resting time.