Sourdough focaccia, · 2 tray (30 × 40 cm)

Mix 14 ⅔ cups bread flour, 3.31 lb water and 14 oz active levain (100% hydration); rest 30 min. Add 1.5 oz fine salt, 3.5 oz water (the rest) and 2.75 oz extra virgin olive oil and squeeze in.

Bulk ferment with 4 sets of coil folds in the first 2 hours.

Cover and refrigerate.

Pour half of 4 oz extra virgin olive oil, for the tray and top into the tray, tip the dough in and stretch it gently to the corners.

Proof at room temperature.

Drizzle with the rest of the oil, dimple to the bottom with oiled fingers, scatter 0.25 oz rosemary leaves and 0.25 oz flaky salt.

Bake at 230 °C.