Mixed Berry Pie with Frozen Berries

I love this delicious mixed berry pie with frozen berries because it can easily be made year-round. Frozen berries are cooked and thickened before baking, to prevent your pie filling from being runny. The sweet and slightly tart berry pie filling is encased in a flaky, buttery pie crust for pie perfection.

And for more berry pies, try strawberry blueberry pie, an all-pink lattice strawberry pie, or fresh blueberry pie.

Ingredients

Flaky Pie Crust

• All purpose flour - creates an elastic dough that's easy to roll and shape.
• Salt - enhances the other flavors in the buttery crust
• Ground cinnamon - optional; adds a warm, spiced flavor to the crust
• Unsalted butter - cut your butter into small cubes and keep it cold in the fridge to make sure it doesn't melt out
• Ice cold water - use ice cold water to prevent butter in your pie dough from softening or melting
• Egg - an egg is used for the egg wash to get a beautiful golden color on the crust

Berry Pie Filling

• Frozen berries - I usually use a mix of raspberries, blackberries, blueberries and strawberries; any frozen berries will work
• Lemon juice and lemon zest - adds a tangy, citrus flavor that goes well with berries
• Ground cinnamon - adds a warm, spiced flavor
• Granulated sugar - sweetens the pie filling
• Cornstarch - thickens the pie filling so it doesn't all pour out when you slice your pie

How to Make a Berry Pie with Frozen Berries

These are the general steps to make this recipe. For the full step-by-step directions and ingredient measurements, scroll down to the recipe card at the bottom of this post.

Make the Pie Crust

1. Dry ingredients: In a large mixing bowl, whisk together the flour, salt and cinnamon.
2. Add butter: Toss the cold cubed butter into the dry mixture. Squeeze each piece of butter between your fingers and your thumb to flatten and break it down a bit. The butter pieces should roughly be the size of half a walnut.
3. Add water: Add the ice cold water one tablespoon at a time and mix with a fork until it holds its shape when squeezed in the palm of your hand.
4. Chill: Divide and shape the dough into a larger disc and a slightly smaller disk.
   Wrap both discs individually in plastic cling wrap and refrigerate for at least 1 hour.

Make the Pie Filling

1. Cook the berries: On medium heat in a large saucepan, cook the berries, lemon juice, lemon zest, cinnamon and granulated sugar for about 10 minutes, until the berries release their juice.
2. Add cornstarch: Stir in the cornstarch and increase the heat to high. Boil for one minute, then remove the saucepan from the heat.
3. Cool: Let cool to room temperature to thicken fully.

Assemble and Bake the Pie

1. Prepare the baking dish and oven: Grease a 10 inch pie dish. Preheat the oven to 400°F.
2. Roll out the dough: On a lightly floured surface, roll out the larger pie disc until it will fit into your pie dish.
3. Transfer the dough to the pie dish: Gently transfer the pie crust into the pie dish.
4. Add the pie filling: Pour the thickened room-temperature berry filling into the pie crust. Store it in the fridge again while you prepare the top pie crust.
5. Cut out the top crust: On a lightly floured surface, roll out the smaller disc of pie crust. Use cookie cutters to cut out shapes from the pie crust.
6. Add the top crust: Add the cut-out shapes of pie crust on top of the pie filling.
7. Add the egg wash: Whisk the egg in a small bowl, then brush onto the pie crust.
8. Bake: Bake for 20 minutes, then reduce the temperature to 375°F and bake for another 45 - 60 minutes, until the crust is golden.
9. Cool and serve: Allow to cool for at least 30 minutes, then slice up and enjoy!

Recipe Tips

• Cornstarch needs to come to a boil for one minute to activate its thickening powers, so don't skip this step! Otherwise your pie filling might be runny.
• Keep the butter cold at all times. If the butter starts to soften or become warm, pop your dough in the fridge for 15 minutes to allow the butter to cool and become firm again.
• Use ice cold water in the pie dough. If you use room temperature or warm water, it could soften the butter in your pie crust.
• Mix the pie dough with a fork just until it holds its shape when you squeeze it in your hand. You don't want to overwork your pie dough, which could cause it to be tough.
• Cooking your pie filling before baking your pie is a foolproof way to ensure a fully cooked pie with a firm filling.

Recipe Variations

• Pie Crust: You can use a store bought pie crust instead of making one from scratch.
• Fresh Berries: You can use fresh berries in the pie filling if you don't have frozen berries.
• Ice Cream: Serve your pie with a side of vanilla ice cream for pie a la mode!

Storing

• Fridge - Cover cooled pie loosely with plastic wrap, or store individual slices in an airtight container in the fridge for up to 4 days.
  Allow your pie to cool completely, or else moisture will collect on the plastic wrap and cause your pie to turn soggy.
  
• Freezer - You can freeze this pie unbaked or baked. First, place it in the freezer for one to two hours uncovered. Once it's hard, wrap it in plastic wrap then in aluminum foil. Store in the freezer for up to 3 months.
• If you froze an unbaked pie, bake from frozen and add more time as needed to the total baking time until the pie is fully cooked.
• If you froze a baked pie, thaw it in the fridge overnight, then reheat it before serving.
  
• Reheat - To reheat individual pie slices, wrap them separately in aluminum foil. Place them in a cold oven and turn on the oven to 375°F. After the oven is preheated, leave slices in the oven for 5 additional minutes. Carefully unwrap and enjoy!