Dissolve the yeast in warm water in a small bowl or measuring cup. Sit for 5 minutes until creamy. Measure the flour into a medium bowl and make a well in the center. Add the yeast mixture and cool water. Stir together with a large spoon until sticky and combined. Cover tightly and refrigerate overnight.
To make the Ciabatta:
Add yeast and warm water (for ciabatta portion of the recipe) to a large bowl or the bowl of your stand mixer. Sit for 5 minutes, until foamy (pictured above).
Add biga and flour and mix thoroughly with the foamy mixture (using low speed with the paddle attachment, or just a spoon and some elbow grease!). Sit for 5 minutes. Add salt and cheese. Knead dough until soft and smooth-but still sticky (by hand or with dough hook).
Place dough in an oiled bowl, cover loosely with a towel, and let rise for an hour in a warm place, until doubled in size.
Once dough has risen, spray a rubber spatula with non-stick cooking spray. Place the spatula under the dough in the bowl, lift it on one side and fold the dough over itself toward the middle. Turn the bowl 90 degrees and repeat. Do this 8 times (so 2 full rotations) total. Cover the bowl and let rise for 30 minutes. After 30 minutes, repeat the lift and fold technique for 8 more turns. Cover and let rise for 30 more minutes.
Cover two sheet pans with parchment paper/silpain and sprinkle with flour.
Generously dust work-surface with flour and gently place dough on it (being careful not to deflate it). Flour the top of the dough and divide into 4 equal sized pieces. Take one portion of dough and press it into a 6x3 in. rectangle (doesn't need to be perfect). Fold the shorter ends of the dough towards the middle in thirds, like a business letter. Transfer folded dough to a prepared baking sheet, placing it seam side down. Repeat with each of the additional 3 pieces, having 2 loaves on each baking sheet. Use fingertips to gently dimple the loaves, pressing down like you would on piano keys. Cover and let rise 30 minutes, then dimple again.
Preheat oven to 500° F.
Spray loaves lightly with water from a spray bottle (or just use your fingers to lightly flick water on them) and place cookie sheets in the oven. (If both sheets can't fit on the middle rack, the racks in the upper and lower thirds of the oven, switching and rotating the sheets periodically)
Bake 5 minutes-spraying with water twice more during that time.
Reduce heat to 475° F and bake 10–15 more minutes until the loaves are golden brown and sound hollow when tapped.
Cool to room temperature before slicing and serving.
This recipe uses 1 packet of active dry yeast, divided.
You can sub in your favorite cheese or omit it entirely from the recipe.
If using a salty cheese you may want to reduce the salt in the dough