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Rhubarb Crumb Pie

Rhubarb Crumb Pie is bursting with fresh rhubarb. The filling has a tart-sweet flavor and beautiful pink color. The pie is finished with a crumb topping made with brown sugar and oats.

a slice of rhubarb crumb pie on a white plate. Pie pan in background.

There’s a reason rhubarb is called the “pie plant”. Because it makes the best pies!! Although it’s almost impossible to choose a favorite pie (because all the pies are awesome) if I had to choose, rhubarb would certainly be in the running.

On that note, since we can’t have too many rhubarb pie recipes, today I’ll share this lovely recipe for Rhubarb Crumb Pie. The crunchy, oaty topping is the perfect texture and flavor with the sweet/tart filling.

Tips for making a great Rhubarb Crumb Pie:

  • “Macerate” the chopped rhubarb with sugar to draw out the juices. When uncooked fruit is tossed with sugar, the sugar is drawn into the fruit and reinforces the cell walls. This helps the fruit maintain it’s shape while baking. The rhubarb will still soften, but it won’t become a total mush. Yes, “total mush” is a technical pastry term…
  • The butter for the crumb topping should be slightly cool but a little pliable. If the butter is very cold it will be more difficult to cut it into the dry ingredients. If the butter is soft and melty, it will completely mix into the dry ingredients and you won’t get nice distinct clumps of crumb topping.
  • Precook the rhubarb juice with the cornstarch to activate the cornstarch. This helps prevent runny pie filling.
  • Place the pie on a sheet pan lined with aluminum foil or parchment. Because rhubarb has so much moisture, it will often boil over in the oven.
  • If you do get boil overs with burnt rhubarb juice on the sheet pan, just soak it in water and the cooked juice will eventually melt away.
  • Bake the pie until the fruit in the center of the pie is tender and the juices are bubbling.
  • The pie is best the day it’s baked but can be stored at room temperature for several days.

Scroll through the step-by-step photos to see how to make Rhubarb Crumb Pie:

A bowl of chopped rhubarb with sugar.
Toss the chopped rhubarb with the sugar to “macerate” for 1 hour.
A bowl of chopped rhubarb coated with sugar syrup.
After 30 minutes the sugar has started to melt and some of the juices are released from the rhubarb.
a bowl of chopped rhubarb with sugar syrup
After 60 minutes a lot more juice has been release from the rhubarb.
a pot of boiling rhubarb juice and a bowl with corn starch slurry
Add the cornstarch slurry to the boiling rhubarb juice. Precooking activates the starch to prevent runny pie filling.
a pot of boiling rhubarb juice thickened with cornstarch
When the juice/cornstarch mixture comes to a boil, remove it from the heat and toss it with the rhubarb pieces.
an unbaked pie shell filled with rhubarb
Pour the rhubarb into the pie shell, put the pie on a lined sheet pan for easier cleanup in case of boil overs.
a rhubarb crumb pie ready for the oven
Crumble the oat topping over the filling, then bake.
a freshly baked rhubarb crumb pie on a table with serving dishes.
a slice of rhubarb crumb pie on a white plate.

I am obsessed with the unique flavor of rhubarb. You too? Here are a few more recipes for you to try:

If you love this recipe as much as I do, please consider giving it a 5-star review.

a slice of rhubarb crumb pie on a white plate

Rhubarb Crumb Pie

Yield: 8 portions
Prep Time: 45 minutes
Macerating Time: 1 hour
Bake Time: 1 hour
Total Time: 2 hours 45 minutes

Pure Rhubarb Pie just might be the best fruit pie of all. The filling has a tart-sweet flavor and beautiful pink color. The pie is finished with a crumb topping made with brown sugar and oats.


  • 2 1/2 lbs (1.12 kg) rhubarb, cut into 1" pieces
  • 2 1/2 cups (1 lb 4 oz, 560g) granulated sugar
  • 1 teaspoon finely grated fresh lemon zest
  • 6 tablespoons (1.75 oz, 48g) corn starch
  • 1/2 recipe Perfect Pie Crust
  • Pinch of salt

Crumb Topping

  • 1 cup (5oz, 140g) all purpose flour
  • 1 cup (3 oz, 84g) old fashioned rolled oats
  • 1/4 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1/4 teaspoon cinnamon
  • 1/2 cup (4 oz, 112g) brown sugar
  • 1/4 cup (2 oz, 56g) granulated sugar
  • 1/2 teaspoon vanilla
  • 1 1/2 sticks (6 oz, 168 g) unsalted butter, cool and slightly pliable


  1. In a large bowl, combine the rhubarb pieces, sugar, salt and lemon zest. Toss to combine. Allow the fruit to macerate at room temperature for 1 hour.
  2. Roll the pie dough and line the bottom of a 9" pie plate. Trim the crust to even out the edges. Use your fingers or a fork to crimp the crust. Refrigerate until ready to bake. If working more than a couple hours ahead, wrap the pan to prevent the dough from drying out.
  3. Strain the rhubarb and collect the juice. Combine the corn starch with 1/4 cup of the juice and whisk until smooth. Bring the remaining juice to a boil in a small saucepan. Whisk the cornstarch slurry into the boiling juices. Whisking constantly, cook the juice mixture until it is at a full boil.
  4. Toss the thickened juice with the rhubarb slices. Preheat the oven to 350°F. Line a sheet pan with parchment paper or aluminum foil.
  5. Remove the pie plate from the refrigerator and pour the filling into the pie plate. In the same bowl from the rhubarb, combine the flour, oats, baking soda, salt, brown sugar, granulated sugar and vanilla. Mix to combine the ingredients.
  6. Toss in the butter and mix with your fingers until the butter bits are no larger than a pea and the dough clumps together when squeezed. Crumble the topping evenly over the rhubarb filling.
  7. Set the pie onto the parchment lined baking sheet. Bake the pie on the bottom rack of the oven for about 1-1 1/2 hours. The filling is ready when the fruit in the center is tender and you can see the juices bubbling.
  8. Cool at least 2 hours to allow the filling to set before slicing. The pie will keep at room temperature for several days.

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Wednesday 22nd of July 2020

Looks yummy! I like your tidbits with macerating the rhubarb.. can I add strawberries to this? Not sure if I can add Without having to alternate something else.. thanks!

Eileen Gray

Wednesday 22nd of July 2020

Yes, you can add strawberry to this pie. I would suggest you just swap out equal amount of rhubarb for strawberry.


Tuesday 2nd of June 2020

Cant wait to try this.

It states "1.2 tsp vanilla." Is this 1 and 1/4 tsp or something else?

Eileen Gray

Tuesday 2nd of June 2020

That should be a 1/2 tsp. It's been fixed. Thanks.

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