What is windowpane test?

Pinch off a small piece of dough and stretch it gently between your fingers. If it stretches thin enough to see light through without tearing — a translucent &ldquo;windowpane&rdquo; — the gluten is fully developed and the dough is ready to bulk-ferment. The test works because well-developed gluten is elastic enough to stretch into a near-transparent sheet without breaking; under-developed gluten tears immediately. Most common in enriched-bread recipes (brioche, challah, sandwich loaves) where the gluten network has to support a lot of fat and sugar without collapsing. Not applicable to gluten-free doughs — there's no gluten to test — and unnecessary for high-hydration sourdoughs where the dough's slack texture makes the pull-and-stretch test meaningless.