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This blueberry rhubarb pie strikes a good balance between tart and sweet. The rhubarb adds a bright, tangy flavor, the blueberries round everything out, and the filling bakes up thick enough to slice without turning into a runny mess.
Using frozen fruit makes it easy to make any time of year, and the flaky double crust finishes it off right.
Here’s Why This Blueberry Rhubarb Pie Recipe Works
Frozen fruit makes it easy. You don’t have to wait for rhubarb season to make this pie. Frozen rhubarb and blueberries give you a filling with plenty of flavor and make this recipe easy to pull together any time of year.
The filling sets up well. Quick-cooking tapioca thickens the fruit juices so the pie holds together better once it cools. That means you get slices that hold their shape instead of a runny filling all over the plate.
The spices don’t take over. A little cinnamon and nutmeg add warmth, but they stay in the background where they belong. The fruit still gets to be the main event.
The all-butter crust is worth it. It bakes up crisp, flaky, and sturdy enough to handle the juicy filling. And let’s be honest, all-butter pie crust just tastes better.
Key Ingredient
Rhubarb: Use frozen rhubarb cut into even ½-inch pieces so it cooks evenly.
Blueberries: Add them straight from the freezer, no need to thaw.
Quick-cooking tapioca: This thickens the filling so the pie slices better once cooled. I like to grind it first for a smoother texture, but that step is optional.
Sugar: Keeps the balance without making the pie overly sweet. Adjust slightly if needed.
Lemon juice: Brightens the flavor and balances the fruit.
Butter: Adds richness and rounds out the filling as it bakes.
If you have extra blueberries, consider using them in these low carb blueberry galettes by Abby at Stem and Spoon or our blueberry banana bread (which is definitely not low carb.
If you like this flavor combo, my strawberry rhubarb slab pie is another good one to keep on hand. I also have a strawberry rhubarb crisp if you’re after something a little more straightforward.
Recipe Tips
Layer the fruit and butter. Dotting the butter between layers helps distribute it more evenly through the filling.
Watch the crust. Bake the pie hot at first, then reduce the heat so the filling has time to cook through. Cover the top loosely if it starts to brown too fast.
Cool it before slicing. The filling needs time to set. For neat slices, let the pie cool completely, then chill it.
Use a lined baking sheet. Bake the pie on a parchment-lined sheet pan to catch any drips.
Cut the rhubarb evenly. Try to keep the pieces close to the same size so they cook at the same rate. Big chunks stay too firm while smaller ones break down.
Don’t skip the vents. Cut a few good slits in the top crust so steam can escape. If not, the filling can bubble up and push through the edges.
Chill the dough if it softens. If the crust starts getting sticky while you’re rolling it out, slide it back into the fridge for a few minutes. It’s a lot easier to handle when it’s cold.
Use a metal or glass pie plate. These conduct heat better than ceramic and help the bottom crust bake through instead of staying pale.
Let it bake long enough. Look for the juices to bubble in the center, not just around the edges. That’s your sign the filling is fully cooked and will set properly.
If you want something a little more simple, try our mini blueberry tarts.
Blueberry Rhubarb Pie
This blueberry rhubarb pie is worth the time it takes to do it right. Bake it until the filling is bubbling in the center, let it cool long enough to set, and you’ll get slices that actually hold together.
The balance of tart rhubarb, sweet blueberries, and flaky crust is hard to argue with, and it gets even better with homemade whipped cream or a scoop of homemade vanilla ice cream on the side.
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Blueberry Rhubarb Pie
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Ingredients
- 1 recipe double crust pie crust, homemade or store-bought
Pie Filling
- 3 cups frozen rhubarb, cut into ½-inch pieces
- 3 cups frozen blueberries
- 2 tablespoons fresh lemon juice
- ¾ cup granulated sugar
- ⅓ teaspoon salt
- 2½ tablespoons quick-cooking (instant) tapioca
- 1 teaspoon ground cinnamon
- ⅛ teaspoon freshly grated nutmeg
- 2 tablespoons butter, cold
- 1 egg white, whisked with 1 tablespoon cold water
- coarse sugar
Instructions
- If you are making a homemade pie crust, prepare the dough and chill it according to the recipe directions.
- Preheat the oven to 400°F and place the oven rack in the lowest position. Fit the bottom crust into a 9-inch deep-dish pie plate and set it aside.
- Add the rhubarb and blueberries to a large bowl. Drizzle the lemon juice over the fruit and toss to combine.
- In a small bowl, whisk together the sugar, salt, tapioca, cinnamon, and nutmeg. Pour the sugar mixture over the fruit and toss until everything is well coated.
- Pour the fruit mixture into the prepared pie crust and spread it out evenly. Dot the top of the filling with the pieces of butter.
- Roll out the top crust then place it over the filling. Trim the excess dough and crimp the edges. Brush the top lightly with the egg white wash and sprinkle with coarse sugar. Cut a few steam vents, and set the pie on a parchment-lined baking sheet.
- Bake the pie for 25 minutes. Reduce the oven temperature to 350°F and continue baking for 55 to 60 minutes, or until the crust is deep golden brown and the filling is bubbling through the vents. If the top starts browning too quickly, cover it loosely partway through baking.
- Remove the pie from the oven and place it on a wire rack. Cool for 2 hours, then refrigerate until cold before serving.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Like this recipe? Rate & comment below!
Can you make this with fresh fruits instead of frozen?
Yes, you can. Use the same amounts. Thanks for the question.
I can’t say I’ve ever had blueberries and rhubarb together but this combo sounds super delightful! I love the look of this pie – it looks and sounds like such a perfect summer dessert!
Hi, Katerina…I have to confess…this was my first taste of the combination and it is super delightful! Thanks for your comments, I hope you try it soon.
I love the combo of blueberries and rhubarb…definitely something I need to try too. The pie looks sensational.
Thank you, Angie….It is delicious, try it, you will like it!