Time: 1.5 days
Yield: 3 sandwich loaves
I looked to Breadtopia and Maurizio's ciabatta recipes to get insight on proofing times, though my method and inoculation (% starter) varies from theirs.
Mature starter: 75g / 52%
Bread flour: 145g / 100%
Water: 145g / 100%
Water: 170g / 61%
Bread flour: 280g / 100%
Levain: 340g / 121%
Salt: 9g / 3%
Olive oil: 13.5g / 5%
Make levain. Wait until at least doubled, 4-5 hrs for me.
Mix starter, flour, water in standing mixer on speed 2 for 6-8 min.
Cover, let rest for 20 min.
Add salt, olive oil. Knead on speed 2 until incorporated.
Bulk ferment for 3 hrs, stretching and folding every 30 min (6x).
Cover, put in fridge, retard overnight.
Flour a couche very well. Divide into three equal pieces and gently stretch out once on couche. Careful not to overly degas.
Cover and proof for 2 hours.
1 hr before proofing is done, preheat oven to 475F with baking stone on middle rack and steam pan at the base of the oven (this can be any pan - you will pour water in it to create steam once ciabattas are loaded in oven).
Get parchment slips ready (1 per ciabatta). Gently rest on top of each ciabatta. With one hand, hold cutting board slanted, at the edge of the parchment and couche. With your other hand, QUICKLY flip couche over onto cutting board so that ciabattas are transferred to parchment slips on cutting board.
Act quickly. Transfer ciabattas to baking stone. Pour some water into the steam pan. Bake for 10 min.
Take steam pan out of oven and remove parchment paper after 10 min. Bake for another 8 min.
Remove ciabattas from oven, place on cooling rack. Let cool completely before slicing.