Yes, you can bake sourdough bread for longer than the typical 30 minutes for expansion and 15-20 minutes for color, but there are some considerations to keep in mind. As the baking time is extended beyond these usual ranges, the following things might happen:
Drier Crumb: The longer you bake the bread, the more moisture will be driven out from the crumb (the interior of the bread). This can result in a drier texture, which may not be desirable for some people, especially if you prefer a moist and tender crumb.
Harder Crust: Prolonged baking will lead to a thicker and harder crust. While some people enjoy a deeply caramelized and crunchy crust, excessive baking can make it too hard to chew and may become difficult to slice.
Loss of Aroma: The longer the bread bakes, the more aromatic compounds in the bread can be lost due to evaporation. This could affect the overall flavor and aroma of the final product.
Changes in Flavor: Overbaking may result in a more intense or even bitter flavor due to further caramelization and Maillard reactions. This can be appealing to some, but it might be overpowering for others.
Risk of Burning: Though you asked not to mention burned, it's essential to be aware that if you bake the bread for far too long, there is a significant risk of burning, which will make the bread inedible.
Loss of Oven Spring: As the crust becomes harder, it can hinder the oven spring, which refers to the final rise the bread experiences in the oven. This can result in a denser loaf with less volume.
Structural Changes: Prolonged baking can lead to more significant structural changes in the bread, affecting its texture and overall appearance.
It's worth noting that some sourdough recipes may indeed call for longer baking times depending on the desired outcome. However, to achieve the best results, it's essential to experiment carefully and monitor the bread during baking to prevent any undesirable consequences. Every oven and sourdough recipe is unique, so you might need to adjust the baking time and temperature to find the sweet spot for your specific preferences and ingredients.