Rhubarb Blueberry Pie with the Flakiest Butter Crust
This stunning Rhubarb Blueberry Pie pairs tart rhubarb with sweet, jammy blueberries in a golden, flaky butter crust. The ultimate summer pie that tastes like it came straight from a farmhouse kitchen.
The Summer Pie You Did Not Know You Were Missing
If you have never paired rhubarb and blueberries in a pie before, prepare to wonder how you ever lived without it. Tart, fibrous rhubarb is the great equalizer here. It tempers the sweetness of ripe blueberries and creates a filling that is deeply fruity, slightly jammy, and complex in a way that a single-fruit pie simply cannot match. This is the kind of blueberry rhubarb pie recipe that earns a permanent spot in your warm-weather rotation.
This recipe draws from the same tradition as a classic Saskatoon rhubarb pie from the Canadian prairies, where cooks have long known that a slightly astringent berry-like fruit alongside something sweet is pure magic. Whether your garden is overflowing with rhubarb stalks or you spotted a gorgeous bundle at the farmers market, this is exactly where they belong.
Why This Blueberry Rhubarb Pie Works So Well
There is a little kitchen science behind why rhubarb and blueberry recipes are such a natural match. Rhubarb is intensely tart and releases a lot of liquid when baked. Blueberries are sweet, hold their shape beautifully, and their natural pectin helps the filling set. Together they create a balanced, glossy, jewel-toned filling that slices cleanly and tastes like summer at its absolute peak.
A few things that make this recipe stand out:
- A proper butter crust with cold, cubed butter worked in by hand for maximum flakiness
- Cornstarch as the thickener so the filling sets firmly without tasting starchy or gluey
- Lemon zest and juice to brighten the fruit and bring the whole blueberry rhubarb pie filling together
- An egg wash and coarse sugar finish for that gorgeous bakery-style crust
Chef's Tip: The single most important step in a flaky pie crust is keeping everything cold. If your kitchen is warm, chill your mixing bowl and even your flour before you begin.
The Right Tools Make a Real Difference
A good pastry cutter and a quality 9-inch ceramic or glass pie dish are genuinely worth having for any blueberry and rhubarb recipes you plan to make this season. Ceramic conducts heat evenly and browns the bottom crust beautifully, which is the difference between a soggy base and a properly baked pie.
Tips for the Best Rhubarb Blueberry Pie Filling
The filling is forgiving but a few details matter.
On sugar: Rhubarb varies wildly in tartness depending on the variety and how early in the season it was harvested. Taste your rhubarb raw. If it makes your eyes water, lean toward the full three-quarters cup of sugar. If it is mild and pink, you can pull back by a couple of tablespoons.
On texture: Slice rhubarb into roughly half-inch pieces, not too thin. Pieces that are too small dissolve entirely into the filling and you lose that pleasant, slightly toothsome contrast against the soft blueberries.
On frozen fruit: Using frozen blueberries or frozen rhubarb works beautifully in this blueberry rhubarb recipes context. Just keep them frozen until the moment you toss them with the sugar mixture, and bump up your cornstarch by one extra tablespoon.
Warning: Do not skip the cooling time. A pie that is cut warm will have a soupy filling no matter how well it was made. Give it at least two full hours on the rack.
From Lattice to Upside Down: Fun Variations
Once you have mastered the classic version, this base filling opens up a world of rhubarb berry pie possibilities.
- Lattice top: Weave strips of dough over the filling for a traditional, showstopping presentation
- Blueberry rhubarb upside-down cake style: Pour the filling into a buttered skillet, top with a simple vanilla sponge batter, and bake for a rustic, inverted dessert that is just as impressive
- Crumble top: Swap the top crust for an oat-brown sugar crumble for a more casual, weeknight-friendly version
- Saskatoon rhubarb pie twist: Swap half the blueberries for Saskatoon berries if you can find them for a nuttier, earthier filling that is absolutely worth seeking out
All of these variations use the same blueberry rhubarb pie filling recipe as the base, so once you know it, you know it.
Ready to bake? Here is the full recipe with all the details you need:
Rhubarb Blueberry Pie with the Flakiest Butter Crust
This stunning Rhubarb Blueberry Pie pairs tart rhubarb with sweet, jammy blueberries in a golden, flaky butter crust. The ultimate summer pie that tastes like it came straight from a farmhouse kitchen.
Ingredients
- 2 1/2 cups all-purpose flour, plus more for dusting
- 1 tbsp granulated sugar, for the crust dough
- 1 tsp salt
- 1 cup unsalted butter, very cold, cut into small cubes
- 6 tbsp ice water, add one tablespoon at a time
- 3 cups fresh rhubarb, trimmed and sliced into 0.5-inch pieces
- 2 cups fresh blueberries, rinsed and patted dry
- 3/4 cup granulated sugar, for the filling, adjust to taste
- 3 tbsp cornstarch
- 1 tsp lemon zest, freshly grated
- 1 tbsp lemon juice, freshly squeezed
- 1/2 tsp vanilla extract
- 1 large egg, beaten, for egg wash
- 1 tbsp coarse sugar, for sprinkling on top crust
Instruction
Make the pie crust: In a large bowl, whisk together the flour, 1 tablespoon sugar, and salt. Add the cold cubed butter and use a pastry cutter or your fingertips to work it into the flour until the mixture resembles coarse crumbs with a few pea-sized butter pieces remaining.
Drizzle in ice water one tablespoon at a time, tossing gently with a fork after each addition. Stop adding water when the dough just holds together when pinched. Divide the dough in half, flatten each half into a disk, wrap in plastic wrap, and refrigerate for at least 1 hour or up to 2 days.
Preheat your oven to 425 degrees F (220 degrees C). Place a rimmed baking sheet on the lower oven rack to catch any drips.
Make the filling: In a large bowl, combine the sliced rhubarb, blueberries, 3/4 cup sugar, cornstarch, lemon zest, lemon juice, and vanilla extract. Toss gently until the fruit is evenly coated. Let the filling sit for 10 minutes while you roll out the crust.
On a lightly floured surface, roll one dough disk into a 12-inch circle. Carefully transfer it to a 9-inch pie dish, letting the excess hang over the edges. Pour the blueberry rhubarb pie filling into the crust and spread evenly.
Roll the second dough disk into another 12-inch circle. Either lay it over the filling as a full top crust, or cut it into strips for a lattice top. If using a full crust, cut several slits to vent. Trim, fold, and crimp the edges together to seal.
Brush the top crust evenly with the beaten egg wash and sprinkle generously with coarse sugar.
Place the pie on the preheated baking sheet. Bake at 425 degrees F for 20 minutes, then reduce the oven temperature to 375 degrees F (190 degrees C) and continue baking for 35 more minutes, until the crust is deep golden and the filling is bubbling through the vents.
Transfer the pie to a wire rack and let it cool for at least 2 to 3 hours before slicing. This allows the blueberry rhubarb pie filling to set properly.
Equipment
- 9-inch pie dish
- Large mixing bowl
- Pastry cutter or food processor
- Rolling pin
- Rimmed baking sheet
- Pastry brush
- Wire cooling rack
- Plastic wrap
Notes
Serving and Storing Your Pie
Serve this pie at room temperature for the cleanest slices, with a generous scoop of vanilla bean ice cream or a cloud of lightly sweetened whipped cream. The contrast of cold cream against the sweet-tart filling is absolutely perfect.
Leftovers keep at room temperature for two days, covered loosely with foil. For longer storage, refrigerate for up to five days. If you want to freeze the whole unbaked pie, assemble it completely, wrap it tightly in plastic wrap and foil, and freeze for up to three months. Bake it straight from frozen at 375 degrees F, adding about 30 to 35 extra minutes to the bake time.
