# What you'll need:
→ Dough
01 - 3 cups bread flour
02 - 1/2 cup active sourdough starter at 100% hydration
03 - 1 cup whole milk, lukewarm
04 - 1/4 cup unsalted butter, softened
05 - 1/4 cup granulated sugar
06 - 1 large egg
07 - 1 teaspoon fine sea salt
08 - Zest of 1 lemon
→ Blueberry Lemon Swirl
09 - 1 cup fresh or frozen blueberries
10 - 1/4 cup granulated sugar
11 - 2 tablespoons lemon juice
12 - 1 tablespoon cornstarch
→ Optional Glaze
13 - 1/2 cup powdered sugar
14 - 1 to 2 tablespoons lemon juice
# Method:
01 - In a small saucepan, combine blueberries, sugar, and lemon juice. Cook over medium heat, stirring frequently, until the berries burst and release their juice, approximately 5 to 7 minutes. Stir in cornstarch and continue cooking for 1 to 2 minutes until the mixture thickens. Transfer to a bowl and cool completely.
02 - In a large bowl or stand mixer, combine lukewarm milk, sourdough starter, softened butter, sugar, egg, salt, and lemon zest. Mix until all ingredients are incorporated. Gradually add flour and knead for 8 to 10 minutes until the dough becomes smooth and elastic.
03 - Place the dough in a lightly greased bowl and cover with a damp cloth. Allow the dough to rise at room temperature until it doubles in size, approximately 4 to 6 hours depending on sourdough starter activity.
04 - Turn the dough onto a floured work surface and roll into a 9 by 16 inch rectangle. Spread the cooled blueberry swirl evenly across the dough, leaving a 1 inch border on all sides.
05 - Starting from the short end, roll the dough tightly into a log shape. Place seam-side down in a greased 9 by 5 inch loaf pan.
06 - Cover the loaf pan with a damp cloth and let rise at room temperature for 1 to 2 hours, until the dough is puffy and nearly doubled in height.
07 - Preheat the oven to 350 degrees Fahrenheit. Bake the loaf for 35 to 40 minutes until the top is golden brown and the loaf sounds hollow when tapped on the bottom.
08 - Whisk together powdered sugar and lemon juice until smooth. Once the bread has cooled, drizzle the glaze over the top.