Udisha
Weak starter
The starter is crucial for the perfect sourdough bread. If it weak or inactive, or has not doubled in size, it will not make your bread rise. Make sure that the starter has been fed recently so that it has the required strength to lift the bread.
Incorrect proofing time
When baking sourdough bread, timing is key. The bread needs to be fermented for the right amount time. If you allow it to ferment for too long (over-proofing) or too less (under-proofing), the gluten structure will collapse and you will have a flat bread.
Weak gluten development
Gluten in the dough traps the bubbles that the starter creates, which is important. Unless you knead and stretch the dough properly, the dough will not be strong enough to rise when baked.
Low oven temperature
Low heat will not help you bake the perfect sourdough. To rise properly, the dough needs enormous amount of heat, so make sure that the oven is hot enough for the bread to bake and rise perfectly.