Bread structure is the result of four simultaneous processes: gluten network development (protein), yeast fermentation (carbon dioxide production), starch gelatinisation (in the oven), and Maillard browning (crust development). Understanding these four processes and how they interact explains every aspect of bread behaviour — why kneading matters, why temperature controls rise, why steam in the oven produces crust, why the correct oven temperature produces an open crumb.
**Gluten development:** - Wheat flour contains two proteins: glutenin (forms elastic strands) and gliadin (forms viscous, extensible strands) - When mixed with water, these combine to form gluten — a viscoelastic network that can both stretch (gliadin contribution) and snap back (glutenin contribution) - Kneading aligns and strengthens this network — longer kneading = more aligned gluten = stronger structure - Autolyse (resting the mixed dough before adding salt or yeast): allows glutenin and gliadin to hydrate and begin forming bonds without mechanical disruption — produces a more extensible, less elastic dough **Yeast fermentation and gas:** - Saccharomyces cerevisiae consumes sugars from the flour, producing CO₂ and ethanol - The CO₂ is trapped in the gluten network as bubbles — the internal gas structure of bread - Rate control: temperature (warmer = faster), hydration (wetter dough = faster fermentation), salt level (more salt = slower yeast) - Flavour development: organic acids (lactic, acetic) from wild yeast fermentation in sourdough produce the characteristic sour complexity **Crust formation:** - Steam in the first 10–15 minutes of baking: keeps the crust surface gelatinised and extensible during oven spring (the rapid rise in the first minutes of baking) - After steam is removed: the surface dries, the temperature rises above Maillard threshold, crust forms - Without steam: crust sets too early, traps the rising gas, and produces a dense, thick-crusted loaf **The structure at the crumb level:** - Open crumb: large, irregular bubbles. Requires high hydration (75–80%+ in sourdough), gentle handling to preserve gas cells, good gluten development to support large bubbles - Closed crumb: uniform small bubbles. Lower hydration, more degassing during shaping
Modernist Cuisine at Home + Modernist Bread (where applicable)