Triple Berry Pie celebrates the flavors of summer in one of our favorite desserts. Made with frozen blueberries, raspberries and blackberries this pie is perfect for the fruit lover in your life! This recipe includes instructions for both a pre-cooked berry filling and uncooked filling and instructions for freezing the prepared pie for baking later.
It is important to pre-heat the oven for 30 minutes to 400 degrees before baking. If you are baking on the day of making this pie, adjust the rack to the bottom shelf and middle shelf before turning oven on.
Combine 2 cups of the berries and 3/4 cup sugar on stovetop in a heavy pan over medium high heat. Cook for about 5 minutes until bubbly, stirring while cooking to prevent burning. Mash the berries a bit with back of spoon while cooking.
Whisk together 1/4 cup of cold water and 3 tablespoons of cornstarch in a cup until smooth. Pour the cornstarch mixture (aka slurry) into the cooked berry mixture and mix until blended into the berries.
Cook for an additional 2-3 minutes over medium heat until bubbly again and the cornstarch thickens the sauce has a clear instead of a cloudy appearance. Remove from heat.
Add additional 4 cups frozen berries and dash of salt to the pan. Fold together until blended well.
Pour cooked berry filling into prepared crust. Dot the top of fruit with butter.
Top filling with rolled out crust, making a lattice pattern or simply top the filling with rolled our pastry and crimp edges. Cut a few slits to allow steam to escape. Sprinkle with sugar.
Bake on lowest rack in oven for 45 minutes. If the pie is not brown enough on top after 30 minutes, transfer to middle rack for remainder of baking.
Combine all filling ingredients except the butter into a large bowl. Toss together, place the ingredients into the prepared pastry. If any of the dry ingredients are left in the bowl, sprinkle on top of the dry berry filling in the pastry.
Dot the top of the fruit filling with cut up butter.
Add the top pastry, cut slits to allow steam to escape. Bake for 45 minutes on bottom rack of oven.