Dear all, when we bake our baguette (sourdough with 0,3% yeast) we have a nice oven spring but the crust fails to crack in a rustique way. It stretches more then it breaks. Dear bakers, waht should I do. I am desperate :-)
I have found that if the dough is slightly over-proved that the dough stretches at the slashes giving a 'smooth' shape rather than bursting a little and giving a 'rough' shape with 'ears'/'grigne'.
I imagine the latter is what you are aiming for so perhaps if you try a bake with the dough a little under-proved (or not quite so well proved) you might get the effect that you want.
One other thing that is important in crust formation is the humidity in the oven in the early stages of baking and people using domestic ovens often help this along by spraying water into the oven, placing bowls of boiling water or baking under a cover (cloche).
Let us know how you go and good luck with your projects.