1. Mix your flour with 390g of the water. Cover and let sit for at least 1hr.
2. After 1 hour: in a separate small bowl mix together 1g of instant yeast to 20g of warm water until combined.
3. Now pour the yeast/water mixture into your bowl of dough, along with ripe sourdough starter and salt. Mix until combined, then add in your olive oil. Mix again & perform slap and folds until the dough comes together. It will be very sticky but don’t worry it will come together more in the next few steps. Cover and let rest 30 minutes.
4. Perform 2-3 rounds of stretch and folds each separated by 20-30mins. Tip: during each round of stretch and folds, make sure to stretch the dough enough times until it’s tight and in a natural ball shape (avoid allowing the dough to rip).
5. Perform 2-3 rounds of coil folds each separated by 20-30mins. Dough should show signs of fermentation and be smoother now.
6. After you’re done with all the folds, put dough in the fridge to continue fermenting overnight. (Option to skip this step! If you’d like to bake the same day, just follow the steps below immediately after finishing your folds).
7. The next day, transfer the dough to a parchment lined and oiled 9”×13” pan. If you want it thinner than mine in the video, then you can use a bigger pan. Gently stretch the dough out so it fills the pan (if it doesn’t completely, that’s fine—it will naturally spread when it proofs. Cover and proof for at least 3-4 hrs in a warm environment (near 78*F best). It may take more or less time depending on the temperature! Allow it to almost double in size.
Note: The final baking step is stated to be in the comments and is not included here. Typically, focaccia is baked at high temperature (e.g., 400-425°F or 200-220°C) for 20-30 minutes, until golden brown.
