Ingredients:

  • 2 ½ cups All-Purpose (Plain) Flour
  • 1 Tbsp Granulated Sugar (for crust)
  • 1 tsp Fine Sea Salt (for crust)
  • 1 cup Unsalted Butter, cubed and chilled
  • 8–10 Tbsp Ice Water
  • 3 cups Fresh Blueberries, rinsed and dried
  • 3 cups Fresh Blackberries, rinsed and dried
  • ¾ cup Granulated Sugar (for filling)
  • ¼ cup Instant Tapioca (or Cornstarch)
  • 1 Tbsp Fresh Lemon Juice
  • 1 tsp Lemon Zest
  • ½ tsp Fine Sea Salt (for filling)
  • 1 Large Egg, whisked
  • 1 Tbsp Whole Milk or Water (for wash)
  • 1 Tbsp Demerara or Turbinado Sugar (for sprinkling)

Instructions:

  1. Prepare the Dry Ingredients: Whisk the flour, 1 Tbsp sugar, and 1 tsp salt in a large bowl (or pulse in a food processor).
  2. Cut in the Fat: Add the chilled butter cubes. Use a pastry blender, fingertips, or food processor until the mixture resembles coarse breadcrumbs with some pea-sized chunks of butter remaining.
  3. Add Water: Slowly drizzle in 8 tablespoons of ice water, mixing gently until the dough just comes together. If dry, add the remaining water 1 tablespoon at a time. Do not knead or overmix.
  4. Chill: Divide the dough into two discs (one slightly larger for the bottom crust), wrap tightly in cling film, and refrigerate for at least 60 minutes.
  5. Combine Dry Ingredients (Filling): In a large bowl, whisk together the ¾ cup granulated sugar, tapioca or cornstarch, lemon zest, and ½ tsp salt.
  6. Add Wet Ingredients (Filling): Gently fold in the blueberries, blackberries, and lemon juice. Be careful not to crush the berries.
  7. Rest Filling: Allow the filling to sit at room temperature for 15–20 minutes for the thickener to absorb moisture.
  8. Preheat Oven: Position a rack in the lower third of the oven. Preheat to 220°C (425°F). Place a baking sheet on the rack beneath.
  9. Roll the Bottom Crust: Roll the larger dough disc into a 12-inch circle. Transfer it to a 9-inch deep-dish pie plate. Trim the edges, leaving a 1-inch overhang. Place in the freezer for 10 minutes.
  10. Fill the Pie: Spoon the berry mixture evenly into the chilled crust.
  11. Roll the Top Crust: Roll the second dough disc to an 11-inch circle (or prepare a lattice/decorative top).
  12. Seal and Crimp: Place the top crust over the filling. Trim and fold the edges under the bottom crust’s overhang. Crimp the edges tightly.
  13. Vent and Wash: Cut several vent holes in the top crust. Whisk the egg and milk for the egg wash, brush lightly over the crust, and sprinkle with Demerara sugar.
  14. Bake (Two Temperatures): Bake for 15 minutes at 220°C (425°F). Reduce the oven temperature to 190°C (375°F) and continue baking for 50–55 minutes, or until the filling is visibly bubbling thickly.
  15. Cool Completely: Transfer the baked pie to a wire rack. Cool for a minimum of 2–3 hours at room temperature before slicing. Slicing too early guarantees a runny filling.