A loaf should be turned out from the banneton when it has reached its proofing window and the dough's surface is no longer glossy or overly wet. At this stage the dough will hold shape, show some oven spring potential, and release with a confident flip. If the dough still clings in long, wet strands or leaves a sticky residue, it is either under-dusted or overhydrated and will stick; if it collapses or deflates when touched, it is overproofed and also likely to adhere.
Signs to watch for
Experienced bakers such as Chad Robertson, Tartine Bakery emphasize feeling the dough and observing subtle visual cues rather than relying on clocks alone. A properly proofed loaf often has a slightly domed top and a surface that feels slightly tacky but not sticky. Dusting the banneton well with a mixture that includes rice flour creates a barrier; in humid climates or with high-hydration doughs increase the rice flour proportion to reduce adhesion. Jeffrey Hamelman, King Arthur Flour recommends using a confident, single motion to invert the banneton onto a peel or baking surface so the dough is not handled excessively during release.
Causes of sticking and practical fixes
Human and territorial practice matters: in regions with high humidity traditional bakeries often adapt by increasing rice flour or shortening final proof times. Cultural preferences for open-crumb versus tight-crumb loaves will change acceptable handling: loaves aimed for a very open crumb often require wetter doughs and therefore extra care when turning out.
Timing the turn-out to that proofing window, preparing the banneton correctly, and using a quick, confident flip are the practical steps that prevent sticking and preserve loaf shape.