• In a large bowl, add the yeast and lukewarm water and stir. Allow to sit for 2 minutes.
• Add the flour and salt, stir with a wooden spoon to blend. Cover the bowl with plastic wrap and allow to rest for 8 hours, 14-18 hours preferably, at room temperature.

Lemon Sugar

• Zest a large lemon into 1/3 cup granulated sugar in a small bowl. Use your fingers to rub the lemon into the sugar.
  

Bread Assembly

• Turn the dough out onto a lightly floured surface. Carefully stretch the bread dough into a square. Sprinkle with half of the lemon sugar and 1/2 cup of blueberries.
  
• Fold 1/3 of the dough over.
  
• Top with 1/2 of the remaining lemon sugar & blueberries.
  
• Fold 1/3 of the dough over to cover the blueberries. Top with remaining blueberries and lemon sugar.
  
• Carefully roll the dough, pinching the ends as you go to enclose the fruit. Add any blueberries that pop out.
  
• Carefully form a ball. Pinch any areas that have opened. Place in a bread banneton basket and pinch any open seams. Cover with a damp towel or disposable shower cap (I like this method so I can see the dough), or leave on a floured surface and cover with a lightly floured tea towel. Let the dough rest 1-2 hours at room temperature.
  
• Preheat oven to 475ºF with the cast iron Dutch oven inside for 30-45 minutes.
• Turn the dough out of proofing basket seam side down on a sheet of parchment paper or a silicone bread sling (shown above). Carefully lower into the hot Dutch oven. Use a bread lame, razor blade, or a sharp knife to score the top of the dough. Cover and bake 30 minutes. Remove the lid and continue baking 15-20 minutes longer. Remove and allow to cool 30 minutes, or completely, on a wire rack before slicing.