Open crumb with baker's yeast vs sourdough starter
Something that has been baffling me is why my sourdough have a more open crumb than my yeast breads. I would use the same ingredients and the same hydration, and roughly the same handling. My sourdough breads would turn out with large holes in the crumb but somehow yeast breads would look hardly more open than a sandwich bread (and at 75% hydration!). The only time I have achieved an open crumb, and this was by accident, was with using a 50% biga on my 80-90% hydration ciabatta (wasn't sure about the hydration as I was improvising, hence the accident).
Is this just me or is this everyone's experience in yeast vs sourdough baking? I can't make sense of it, since, if my knowledge is correct, the acid in the sourdough should weaken the gluten right. We should expect the opposite, which is that sourdough should have a less open crumb and less oven spring than a yeasted bread. Could the difference come from the LAB or the different strains of yeast?