• The morning after mixing the leaven (when it is bubbly & active), use your hands to mix together the flour, water, leaven, and salt. After mixing let rest for 10-20 minutes.
• Add the extra virgin olive oil and mix until the dough is well combined.

Bulk fermentation:

• The next steps are very similar to making sourdough bread. For the next two hours stretch the dough every 30 minutes for a total of 4 turns. To fold the dough slightly dampen your hands with water (so the dough doesn’t stick) and gently grab the underside of the dough. Pull it up and then fold it over top of the dough. Turn the container 90 degrees and repeat this action 3 (or so) more times. Each set of folds is called a “turn.” (for more detail on sourdough visit the sourdough bread post)

Proof:

• After two hours transfer the sourdough focaccia dough to a generously oiled (using olive oil) 9x13” metal pan. Using a bench scraper, gently scrape the dough into the pan. Cover with a towel. The dough will proof in this pan for the next two hours before it goes into the fridge overnight.
• Every 30 minutes for the first hour of proofing uncover the pan, wet your hands, and gently stretch the dough into the sides of the pan. It is important not to aggressively tug/pull on the dough—just gently work it into the corners and it will naturally start to spread out over the course of proofing.
• After two hours of proofing, cover the dough and place it in the fridge overnight (if you have a large plastic bag this will work well).
• The next morning, remove the pan from the refrigerator and continue the final 2 hours of proofing. If the dough has not reached the corners of the pan, continue to gently stretch it every hour for the remainder of the proof.

Baking:

• After proofing is complete the dough should be slightly bubbly and back up to room temperature
• Preheat the oven to 450 degrees
• Lightly wet your hands and using your fingers, gently press down into the dough creating dimples. This is what gives focaccia its signature look. It is important to do this step gently. You want to create dimples in the dough but avoid knocking all of the air out of it.
• Drizzle a generous pour of olive oil over the dough, top with a sprinkle of flaky sea salt and chopped rosemary and place it in the 450 degree oven. If you have a pan that will fit over top of the focaccia pan, cover the pan (simulating the effect of a dutch oven and helping with the oven spring) for the first 15 minutes of baking and then let it bake uncovered for the remaining 15-20 minutes until golden brown.