Hello, I am attempting to make a sub roll with a wildly open crumb, which, I hope, will give me the lightness AND the volume I want. I am now happy with the flavor and the crust but that open crumb eludes me. I start with a preferment that is 80% hydration and it uses only 1/32 of a tsp of dry yeast. I cover it and let it rest on the counter for 14 hrs. When ready, it has quadruped in volume and is covered with bubbles. For the dough I use unbleached flour at a 62% hydration and a tiny amount of dry yeast. I let it autolyse for 2 hr and then I add the salt, about 2%. After kneading I bulk ferment for two hrs or until doubled. I use a VERY gentle pre-shape, rest and gentle final shaping (7 inch long torpedo). These I place in my baguette pans, cover and rest until doubled or a tad more. I bake on an oven stone, with steam at 450 F for 18 minutes. Looks nice tastes good but is still too dense for what I want. Any help or general thoughts would be much appreciated. thank you.