Blueberry Pie (Cooks Illustrated)

By pknaub

Why this recipe works:
When perfecting our blueberry pie recipe, we found that adding a peeled, grated Granny Smith apple, rich in pectin, helped thicken the berries and enhance their flavor.

Makes one 9-inch pie

This recipe was developed using fresh blueberries, but unthawed frozen blueberries (our favorite brands are Wyman’s and Cascadian Farm) will work as well. In step 4, cook half the frozen berries over medium-high heat, without mashing, until reduced to 1 1/4 cups, 12 to 15 minutes. Grind the tapioca to a powder in a spice grinder or mini food processor. If using pearl tapioca, reduce the amount to 5 teaspoons. Vodka is essential to the texture of the crust and imparts no flavor; do not substitute.

Ingredients

• Foolproof Pie Dough
• 2 1/2 cups unbleached all-purpose flour (12 1/2 ounces), plus more for work surface
• 1 teaspoon table salt
• 2 tablespoons sugar
• 12 tablespoons cold unsalted butter (1 1/2 sticks), cut into 1/4-inch slices
• 1/2 cup vegetable shortening , cold, cut into 4 pieces
• 1/4 cup vodka , cold (see note)
• 1/4 cup cold water
• Blueberry Filling
• 6 cups fresh blueberries (about 30 ounces) (see note)
• 1 Granny Smith apple , peeled and grated on large holes of box grater
• 2 teaspoons grated zest and 2 teaspoons juice from 1 lemon
• 3/4 cup sugar (5 1/4 ounces)
• 2 tablespoons quick-cooking tapioca , ground (see note)
• pinch table salt
• 2 tablespoons unsalted butter , cut into 1/4-inch pieces
• 1 large egg , lightly beaten with 1 teaspoon water

Preparation

Step 1

For The Pie Dough: Process 1 1/2 cups flour, salt, and sugar in food processor until combined, about two 1-second pulses. Add butter and shortening and process until homogenous dough just starts to collect in uneven clumps, about 15 seconds; dough will resemble cottage cheese curds and there should be no uncoated flour. Scrape bowl with rubber spatula and redistribute dough evenly around processor blade. Add remaining cup flour and pulse until mixture is evenly distributed around bowl and mass of dough has been broken up, 4 to 6 quick pulses. Empty mixture into medium bowl.

2. Sprinkle vodka and water over mixture. With rubber spatula, use folding motion to mix, pressing down on dough until dough is slightly tacky and sticks together. Divide dough into 2 even balls and flatten each into 4-inch disk. Wrap each in plastic wrap and refrigerate at least 45 minutes or up to 2 days.

3. Remove 1 disk of dough from refrigerator and roll out on generously floured (up to 1/4 cup) work surface to 12-inch circle, about 1/8 inch thick. Roll dough loosely around rolling pin and unroll into pie plate, leaving at least 1-inch overhang on each side. Working around circumference, ease dough into plate by gently lifting edge of dough with one hand while pressing into plate bottom with other hand. Leave dough that overhangs plate in place; refrigerate while preparing filling until dough is firm, about 30 minutes.

4. For The Filling: Adjust oven rack to lowest position, place rimmed baking sheet on oven rack, and heat oven to 400 degrees. Place 3 cups berries in medium saucepan and set over medium heat. Using potato masher, mash berries several times to release juices. Continue to cook, stirring frequently and mashing occasionally, until about half of berries have broken down and mixture is thickened and reduced to 1 1/2 cups, about 8 minutes. Let cool slightly.

5. Place grated apple in clean kitchen towel and wring dry. Transfer apple to large bowl. Add cooked berries, remaining 3 cups uncooked berries, lemon zest, juice, sugar, tapioca, and salt; toss to combine. Transfer mixture to dough-lined pie plate and scatter butter pieces over filling.