what is the first stage of baking in the oven?

The first stage of baking in the oven is the formation and expansion of gases, also known as oven spring. When the dough is placed in the oven, yeast and chemical leavening agents rapidly form gases such as carbon dioxide. These gases, along with steam formed from the moisture in the dough, expand and cause the dough to rise quickly. During this stage, the dough increases in size as the gas bubbles expand within the stretchy gluten network. This oven spring happens while the crust is still soft and extensible, allowing the dough to rise before the crust sets and hardens. Steam is often introduced at this stage to keep the crust moist and extensible, helping to maximize the oven spring and prevent premature crust formation. This stage typically occurs at dough core temperatures of about 35°C to 70°C (95°F to 158°F) and lasts for the first several minutes of baking until the yeast activity ceases around 50°C (122°F) and proteins start to coagulate. In summary, the first stage in the oven baking process is the rapid gas formation and expansion that causes the dough to rise significantly, known as oven spring, supported by steam to maintain crust flexibility.