This is the yeast doing its thing – reproducing and emitting gases which helps the dough rise.
As you turn the dough each time, you’ll notice it getting smoother and bigger, lighter and fluffier. This is the yeast doing its thing – reproducing and emitting gases which helps the dough rise. As the dough becomes lighter, turn it more gently each time or pick it up with two hands in the middle and let the ends fold under the dough.