Rhubarb Custard Pie Recipe: Creamy Classic with Flaky Crust

This vintage rhubarb custard pie blends chopped rhubarb with a simple egg yolk custard for a classic, balanced dessert. Fresh rhubarb is preferred for the best texture and flavor, but frozen rhubarb can be used when fresh isn’t available.

Rhubarb custard pie with a slice on a server.

Unlike some modern versions that rely heavily on cream, this old-fashioned recipe uses mostly egg yolks and sugar, with just a tablespoon of cream to loosen the filling. The result is a light custard that lets the rhubarb’s sweet-tart character shine through.

The filling is straightforward and forgiving, delivering a pie that’s pleasantly tart, not overpoweringly sweet, and easy to serve warm or at room temperature.

Ingredients and substitutions

Notes on key ingredients:

Rhubarb – Fresh rhubarb offers the best texture. Frozen rhubarb works, but tends to collapse when cooked, making a slightly thinner pie. If using frozen, add it to the pie from frozen (do not thaw) and allow a few extra minutes of baking to reduce excess moisture.

Egg yolks – Only the yolks are used for the custard. Save the whites for another use or make the optional meringue topping described in the recipe notes.

Heavy whipping cream – One tablespoon of heavy cream (35% b.f.) loosens the custard. You can substitute sour cream or one tablespoon of melted and cooled butter if preferred.

Cornstarch – This is the primary thickener and should not be omitted. Arrowroot or tapioca starch can be substituted if needed.

Pie crust – Use a standard 9-inch unbaked pie shell, homemade or store-bought. A deep-dish shell isn’t necessary since this is not a tall pie, but it will work if that’s what you have.

How to make rhubarb custard pie: step-by-step

Brief visual summary — see the recipe card below for the full ingredient list and instructions.

Step 1: Trim any leaves and slice the rhubarb on the diagonal into 1/2-inch pieces. You need 3 cups of chopped rhubarb.

Rhubarb custard pie filling ingredients in two bowls. — 2

Step 2: Mix the sugar with the cornstarch in one bowl. Whisk the egg yolks, vanilla and cream in another.

Wet and dry filling ingredients combined in a bowl. — 3

Step 3: Combine the egg mixture with the sugar mixture and stir until smooth.

Custard filling combined with chopped rhubarb. — 4

Step 4: Stir the custard mixture into the chopped rhubarb until evenly coated.

Rhubarb filling added to an unbaked pie shell. — 5

Step 5: Spoon the filling into an unbaked 9-inch pie shell and place the pie on a baking sheet to catch any spills.

Step 6: Bake as directed until the filling is set and starting to color in spots.

Recipe tips!

Serve warm with vanilla ice cream or a splash of cream. If you prefer, use the reserved egg whites to make a meringue topping (instructions are in the recipe notes).
If the crust is browning too quickly before the filling is set, loosely cover the pie with foil for the remainder of the baking time.
Test for doneness by gently shaking the pie; the center should not be overly jiggly. The filling will be sliceable but not as firm as a dense custard.
Using frozen rhubarb may require a few extra minutes in the oven to evaporate extra moisture.
Finish with a dusting of icing sugar for a neat presentation, if desired.

Making ahead and storing

This pie can be prepared ahead of time. Refrigerate after baking and bring to room temperature before serving, or reheat loosely covered in a 350°F (175°C) oven for 8–10 minutes. Individual slices can be reheated briefly in the microwave.

Store leftovers in the refrigerator for 3–4 days.

You can freeze this pie, though the custard texture may change slightly. Freezing unbaked is preferable: wrap well and freeze up to 3 months, then bake from frozen, adding extra time as needed.

Get the Recipe: Rhubarb Custard Pie

A vintage rhubarb custard pie with a lightly set egg yolk custard and tart rhubarb, baked in a single 9-inch pie shell.

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Prep Time: 15 minutes

Cook Time: 40 minutes

Total Time: 55 minutes

Yield: 8 servings

Ingredients

3 cups rhubarb, fresh or frozen, cut slightly diagonally into 1/2-inch pieces
1 cup white granulated sugar
2 Tablespoons cornstarch
3 large egg yolks, *see Notes for an optional meringue topping
1 teaspoon vanilla extract
1 Tablespoon heavy whipping cream, or sour cream, or 1 Tablespoon melted and cooled butter
1 9-inch unbaked pie shell, homemade or store-bought, thawed if frozen

Instructions

Preheat the oven to 425°F (non-convection/fan off).
Discard any rhubarb leaves. Cut stalks on the diagonal into 1/2-inch pieces to equal 3 cups and place in a large bowl.
In a medium bowl, stir together 1 cup granulated sugar and 2 Tablespoons cornstarch. In a small bowl, whisk 3 egg yolks, 1 teaspoon vanilla and 1 Tablespoon heavy cream. Add the egg mixture to the sugar mixture and stir until smooth, then combine with the rhubarb.
Spoon the rhubarb filling into an unbaked 9-inch pie shell and set the pie on a baking sheet. Bake at 400°F for 20 minutes, then reduce the oven to 325°F and bake another 20–25 minutes until set and lightly golden. The center should not be overly jiggly.
Remove from the oven and let stand 10–15 minutes before slicing. Dust with icing sugar if desired. Store leftovers in the refrigerator.
Serve warm with vanilla ice cream or a drizzle of cream for a comforting finish.

Notes

Optional Meringue Topping: When the pie is nearly done, whip the reserved egg whites at medium speed until foamy. Gradually add 1/4 cup sugar while increasing speed, then beat until glossy with stiff peaks. Spread the meringue over the hot pie, sealing to the crust, and return to a 325°F oven for 10–15 minutes until the meringue is set and lightly golden.

Refer to the notes and tips above for ingredient substitutions and baking suggestions.

Cuisine: American, Canadian

Course: Dessert

Serving: 1serving, Calories: 256 kcal, Carbohydrates: 41 g, Protein: 3 g, Fat: 9 g.