Bellegarde Bakery Ciabatta

Name: Bellegarde Bakery Ciabatta
Ingredients: 5 cups bread flour (such as King Arthur Unbleached Bread Flour) (about 21 1/4 ounces), plus more for work surface; 2 1/2 cups freshly ground white whole-wheat flour (such as Bellegarde White Wheat) (about 10 3/4 ounces); 1 1/2 cups freshly ground red whole-wheat flour (such as Bellegarde Organic Wheat) (about 6 1/4 ounces); 2 teaspoons active dry yeast; 4 1/4 cups lukewarm water (78°F), divided; 3 tablespoons olive oil or pecan oil; 2 tablespoons fine sea salt; Cooking spray