Bread Basics
Understanding the fundamental biology and chemistry of baking.
The Four Pillars of Bread
At its core, traditional bread requires only four ingredients: flour, water, yeast, and salt. When combined, these elements undergo a fascinating transformation. Flour provides starches and proteins. When water is introduced, two specific proteins (glutenin and gliadin) bind together to form gluten. This elastic network is what gives bread its structure and chew.
The Role of Fermentation
Fermentation is where the magic happens. Yeast—a living microorganism—begins to consume the natural sugars present in the hydrated flour. As it feeds, it expels carbon dioxide gas and alcohol. The stretchy gluten network traps the carbon dioxide bubbles, causing the dough to inflate and rise. The alcohol, alongside organic acids produced during this time, imparts the rich, complex flavors we associate with freshly baked bread.
Hydration and Dough Consistency
Hydration refers to the ratio of water to flour in a recipe, calculated by weight. A lower hydration dough (around 60%) is stiffer, easier to handle, and typically results in a tighter crumb—ideal for sandwich breads or bagels. A higher hydration dough (75% and above) is sticky, slack, and challenging to shape, but it yields the wide open, airy crumb structures seen in ciabatta and artisan sourdoughs.
Baking and Oven Spring
When the proofed dough enters a hot oven, a rapid burst of activity known as "oven spring" occurs. The heat causes the trapped gases to expand rapidly, and the yeast goes into a frenzy of activity before dying off at around 140°F (60°C). Concurrently, steam helps keep the crust pliable so the bread can expand fully. Eventually, the crust sets, and the Maillard reaction browns the exterior, creating a deeply flavored, protective shell.