# What you 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
# How to make it:
01 - In a small saucepan, combine blueberries, sugar, and lemon juice. Cook over medium heat, stirring frequently, until berries burst and release their juice, approximately 5 to 7 minutes. Stir in cornstarch and continue cooking for 1 to 2 minutes until mixture thickens. Transfer to a bowl and allow to cool completely before using.
02 - In a large bowl or stand mixer, combine lukewarm milk, sourdough starter, softened butter, sugar, egg, salt, and lemon zest. Mix until thoroughly combined. Gradually add flour while mixing and knead for 8 to 10 minutes until dough becomes smooth and elastic.
03 - Place dough in a lightly greased bowl and cover with a damp towel. Let rise at room temperature until doubled in size, approximately 4 to 6 hours depending on starter activity.
04 - Turn dough onto a floured surface and roll into a 9 by 16 inch rectangle. Spread cooled blueberry swirl evenly over dough surface, leaving a 1 inch border around edges. Roll up tightly from the short end to form a log shape and place seam-side down in a greased 9 by 5 inch loaf pan.
05 - Cover loaf pan with a damp towel and let rise at room temperature for 1 to 2 hours until dough is puffy and nearly doubled in volume.
06 - Preheat oven to 350°F. Bake loaf for 35 to 40 minutes until golden brown on top and loaf sounds hollow when tapped on bottom.
07 - Once loaf has cooled slightly, whisk together powdered sugar and lemon juice until smooth. Drizzle glaze over cooled bread surface using a pastry brush or spoon.