If you let the dough rise for too long, the taste and texture of the finished bread suffers. Because the dough is fermenting during both rises, if the process goes on for too long, the finished loaf of bread can have a sour, unpleasant taste.
Can I leave my bread to rise overnight? Yes, you can let your bread rise overnight in the fridge. Keep in mind, though, you'll want the dough to come back up to room temperature before baking.