# Ingredient List:
→ Dough
01 - 2 cups bread flour
02 - 1/4 cup granulated sugar
03 - 2 teaspoons fine sea salt
04 - 1 cup whole milk, cold
05 - 1/2 cup active sourdough starter at 100% hydration
06 - 2 tablespoons unsalted butter, softened
→ Butter Block
07 - 1 cup plus 2 tablespoons unsalted butter, cold
→ Egg Wash
08 - 1 large egg
09 - 1 tablespoon milk
# Steps:
01 - In a large bowl, combine bread flour, sugar, and salt. Add cold milk, sourdough starter, and softened butter. Mix until just combined, then knead until smooth and elastic, approximately 8 minutes.
02 - Shape dough into a rectangle, wrap in plastic wrap, and refrigerate for at least 2 hours.
03 - Place 1 cup plus 2 tablespoons cold butter between two sheets of parchment paper. Pound and roll into an 8 by 6 inch rectangle. Chill until firm but pliable.
04 - On a lightly floured surface, roll out dough to a 16 by 8 inch rectangle. Place butter block on one half, fold dough over, and seal edges by pressing gently.
05 - Turn dough 90 degrees and roll into a 24 by 8 inch rectangle. Fold into thirds using a letter fold technique, wrap in plastic, and chill for 1 hour.
06 - Repeat the rolling and folding process two more times, maintaining a 90-degree rotation and chilling 1 hour between each turn.
07 - After the final fold, wrap dough in plastic and refrigerate overnight, 8 to 12 hours, to develop deep sourdough flavor.
08 - Roll chilled dough to a 24 by 12 inch rectangle, approximately 0.2 inch thick. Cut into 12 long triangles using a sharp knife.
09 - Starting from the wide end of each triangle, roll toward the point into a crescent shape, tucking the tip underneath. Place on parchment-lined baking sheets.
10 - Cover loosely with plastic wrap and proof at room temperature until doubled in size, 2 to 3 hours.
11 - Preheat oven to 400°F. Whisk egg and milk together for egg wash. Brush croissants lightly with mixture.
12 - Bake 18 to 22 minutes until golden brown and crisp. Cool slightly before serving.
