How to Bake Strawberry Rhubarb Pie

Tart rhubarb and sweet strawberries in a flaky double crust, thickened so the slices hold together.

Makes

One 9-inch pie, 8 slices

Active time

About 1 hour

Bake

About 1 hour 10 minutes

Cool

At least 4 hours

Strawberry rhubarb pie pairs the sharp, tangy bite of rhubarb with the sweetness of ripe strawberries inside a buttery double crust or lattice. Both fruits release a lot of juice, so the keys are a good thickener, a hot oven to set the bottom crust, and a long cooling time before slicing.

Only the stalks of rhubarb are eaten. The leaves contain oxalic acid and are toxic, so trim them off and throw them away. Fresh rhubarb is best in spring and early summer, but frozen rhubarb and strawberries both work well (see the tips below).

Ingredients

For the double crust

• 2 1/2 cups (315 g) all-purpose flour
• 1 tablespoon sugar
• 1 teaspoon salt
• 1 cup (227 g) cold unsalted butter, cubed
• 6 to 8 tablespoons ice water

For the filling

• 4 cups (about 500 g) rhubarb stalks, cut into 1/2-inch (1 cm) pieces
• 3 cups (about 450 g) strawberries, hulled and quartered
• 1 cup (200 g) granulated sugar, plus more to taste
• 1/4 cup (30 g) quick-cooking tapioca, or 3 tablespoons (24 g) cornstarch
• 1 tablespoon lemon juice
• 1 teaspoon vanilla extract
• 1/4 teaspoon salt
• 1 tablespoon cold unsalted butter, cut into small pieces

For finishing

• 1 large egg beaten with 1 tablespoon milk or cream
• 1 tablespoon coarse sugar (optional)

Instructions

1. Make and chill the dough. Whisk the flour, sugar and salt. Work in the butter until it is in pea- to almond-sized pieces, then stir in just enough ice water for the dough to hold together when squeezed. Divide into two discs, wrap, and refrigerate for at least 1 hour.
2. Prepare the fruit. Cut off and discard any rhubarb leaves, trim the ends, and cut the stalks into 1/2-inch pieces. Combine the rhubarb and strawberries in a large bowl with the sugar, tapioca or cornstarch, lemon juice, vanilla and salt. Stir and let sit for 15 to 20 minutes.
3. Heat the oven. Place a rack in the lower third of the oven, set a rimmed baking sheet on it to catch drips, and heat the oven to 425°F (220°C).
4. Line the pie plate. On a floured surface, roll one disc into a 12-inch (30 cm) circle. Ease it into a 9-inch pie plate, leaving the edge overhanging, and refrigerate while you roll the top.
5. Roll the top crust. Roll the second disc into a 12-inch circle. For a lattice, cut it into ten strips about 3/4 inch (2 cm) wide. For a double crust, leave it whole. Chill it on a parchment-lined sheet.
6. Fill the pie. Stir the fruit once more and pour it into the shell with its juices, mounding it slightly in the center. Dot with the cold butter pieces.
7. Top the pie. Weave the strips into a lattice, or lay the whole crust over the fruit and cut four or five steam vents. Trim the overhang to 1 inch (2.5 cm), fold it under the bottom edge, and crimp. Chill the whole pie for 15 minutes.
8. Glaze. Brush the top crust with the egg wash and sprinkle with coarse sugar if you like.
9. Bake hot, then lower the heat. Bake on the preheated sheet for 20 minutes at 425°F (220°C). Reduce the oven to 375°F (190°C) and bake 45 to 55 minutes more, until the crust is deep golden and the filling bubbles thickly through the vents or lattice.
10. Protect the edges. If the rim browns too fast, cover it loosely with strips of foil or a pie shield for the rest of the bake.
11. Cool completely. Let the pie cool on a wire rack for at least 4 hours. The thickener finishes setting as the filling cools, and slicing early gives a runny pie.

Common problems

• Runny filling: the pie was cut too soon, or the filling never bubbled in the center. Look for thick bubbles at the vents, and cool the pie for a full 4 hours.
• Soggy bottom crust: the oven was too cool or the pie sat on a cold rack. Bake on a preheated baking sheet in the lower third of the oven.
• Stringy or tough rhubarb: the pieces were too large or the stalks were old. Cut them to 1/2 inch, and bake until a knife slides in easily.
• Crust shrinking or slumping: the dough was warm or overworked. Chill the assembled pie for 15 minutes before it goes in the oven.

Keep the pie loosely covered at room temperature for up to 2 days, or in the fridge for up to 4. Because the leaves of the rhubarb plant are toxic, always buy or harvest the stalks only and discard the leaves before cooking. For more on why a cold, lightly mixed dough bakes up flaky, see Why Cold Butter Makes a Flaky Pie Crust.