• 4-6 hours before you are ready to mix the dough, feed the sourdough starter a ratio of 1:1:1, or equal parts flour, water, and starter, and allow it to come to its peak. The exact timing of when it comes to its peak will vary depending on the temperature of your kitchen and the strength of your starter.

Mix the Dough

• Add 100 g (1/2 cup) active sourdough starter, 500 g (4 cups) flour, 400 g (1 2/3 cups) water, 10 g (2 tsp) salt, 3 tbsp lemon juice, 3 tbsp lemon zest, and 50 g (1/4 cup) sugar to a large bowl and combine using a Danish dough whisk until fully mixed. Cover the bowl and let the dough rest at room temperature for 30 minutes to let the flour hydrate. 
• Do a set of stretches and folds. Grab the side of the dough along the side of the bowl, lift it straight up, and then fold it onto itself into the middle of the dough. Rotate the bowl a quarter of a turn and repeat along the sides of the bowl for a total of 12-15 stretches. Cover the bowl and allow to rest for 30 minutes. This completes one set of stretch and folds.
• Continue stretching and folding for a total of 3 sets of stretch and folds. From the first set of stretch and folds to the last, the dough will transform from a sticky dough that covers your hands to an elastic dough with minimal sticking.

Bulk Fermentation or First Rise

• After the last set of stretch and folds, cover the bowl and let rest in a warm spot in the kitchen to bulk ferment, roughly 3-6 hours.

  (Read text above for more information on what to look for when the dough is done bulk fermenting)

Cold Ferment

• Cover the bowl and refrigerate overnight.

Shape and Second Rise

• The next morning, prepare the pan by placing a piece of parchment paper into the bottom of the baking pan and drizzle 30 g (2 tbsp) olive oil evenly over the parchment paper.
• Using a bowl scraper, turn the dough out into the pan. Rub a bit of olive oil onto your fingers and stretch and pull the dough to fit the pan.
• Cover the pan with a tea towel or a bit of plastic wrap and place in a warm place for 4-5 hours.  During this time, the dough will have visibly risen with plenty of air bubbles showing beneath the surface.

  The exact time will largely depend on the temperature of your kitchen. If your kitchen is cool, place the pan in the oven with the light on to create a warmer environment. Be sure to remove it before preheating the oven.

Dimple and Bake

• Preheat oven to 400 degrees.
• Sprinkle blueberries over the top of the dough.
• Pour melted butter evenly over the top of the dough.
• Press your fingertips into the dough, creating dimples across the entire pan. 
• Place into the oven and bake for 30-40 minutes. The focaccia is done when the top is a light golden brown and the internal temperature reads 200 degrees.

Lemon Glaze

• While the bread is baking, prepare the glaze. Juice a lemon and add to a small bowl. In a separate small bowl, whisk 2-3 tablespoons lemon juice and 130 g (1 cup) powdered sugar until smooth. Use more lemon juice, if needed, to create a smooth, pourable lemon glaze.
• Remove the focaccia from the pan and place onto a wire rack to cool, discarding the parchment paper.
• Allow the bread to cool to room temperature before drizzling the glaze over the top of the sourdough blueberry lemon focaccia bread.

Store

• Sourdough blueberry lemon focaccia bread is best the same day you bake it. If you do have leftovers, store them in an airtight container at room temperature and enjoy them within a day or two.