Unique Concord grape pie with a deep purple filling and flaky crust is a distinctive, seasonal family dessert. This rare, old-fashioned pie celebrates autumn grape harvest with bold, fruity flavor.
Preheat the oven to 400°F. Line a 9-inch pie dish with one sheet of pie dough, keeping the second chilled for lattice or top crust.
Rinse Concord grapes, slip skins from all grapes by pinching gently, and reserve the skins. Place the pulp (without skins) in a saucepan over medium heat; simmer for 7-8 minutes until the pulp softens and seeds loosen.
Press the cooked pulp through a sieve or colander to remove seeds, then combine the strained pulp with reserved grape skins in a mixing bowl.
Stir in granulated sugar, flour, lemon juice, and salt. Mix thoroughly until the sugar dissolves and the filling is evenly combined.
Pour the mixture into the prepared pie shell. Dot the surface with butter, cover with remaining pie dough (lattice or full), crimp edges, and cut vents if using a full top.
Bake at 400°F for 20 minutes, then reduce oven temperature to 350°F and bake another 30-35 minutes. The filling should bubble and the crust turn golden brown.
Cool the pie completely on a wire rack to allow the filling to set before slicing and serving.