Old-Fashioned Rhubarb Pie

This is classic, sweet-tart, old-fashioned Straight-up Rhubarb Pie, just like grandma used to make. No fruity distractions - just tangy, sweet-tart rhubarb and tender, flaky pastry.

Jump to:

• Classic Rhubarb Pie, Just Like Mom Made
• Rhubarb Pie Ingredients (Just 5!)
• How to Make Rhubarb Pie from Scratch
• Pro Tips for the Best Rhubarb Pie
• Rhubarb Pie Variations
• Best Pie Plates for Rhubarb Pie
• How to Store Rhubarb Pie
• More Sweet Pie Recipes
• Straight-Up Rhubarb Pie

Classic Rhubarb Pie, Just Like Mom Made

My mom always kept a rhubarb plant tucked into the shady corner of our garden. Every spring—right around the time she started planting tomato starts—it would burst to life with giant green leaves and bold red stalks, announcing the season’s change loud and clear. “Don’t eat the leaves! They’re poisonous!” she’d always warn me. For years, I was afraid to even touch the plant.

(FYI: Rhubarb stalks are completely safe to eat, raw or cooked. But the leaves are toxic to both people and pets.)

Raw rhubarb is sharply sour, with a crunch like celery. Take a bite and your mouth will pucker like you just brushed your teeth and chased it with a lemon. But cook it down with a little sugar, and that’s where the magic happens. The texture softens—like a well-cooked apple—and the flavor mellows into a sweet-tart treat that holds its own in pies, crisps, jams, chutneys, and even savory sauces.

This old-fashioned rhubarb pie recipe skips the strawberries, cherries, and other fruity distractions. It's what’s known as a straight-up rhubarb pie: nothing but sweet-tart rhubarb and tender, flaky pastry. Pure, nostalgic pie perfection.

Want more ways to use rhubarb? Check out our Straight-Up Rhubarb Recipe Roundup for dessert recipes and tips on freezing fresh rhubarb.

Rhubarb Pie Ingredients (Just 5!)

The filling for straight-up rhubarb pie takes just five simple ingredients.

• Rhubarb: You will need 9-10 cups (3½-4 pounds) of rhubarb for one deep dish pie or two standard pies. You will need 4-6 cups (1-1½ pounds) for one standard pie.
  • Fresh Rhubarb: (Recommended) I prefer to use fresh rhubarb. To prepare fresh rhubarb, first remove all the leaves and ends and put them in the compost pile, and then cut the stalks into ½ to ¾-inch pieces.
  • Frozen Rhubarb: You can use frozen rhubarb if need be. In fact, only one of the three pies pictured here was made with fresh rhubarb. (Can you guess which one?) Frozen rhubarb should be fully thawed and room temperature before you start the pie.
• Sugar: Use granulated white sugar for this pie recipe.
• Flour: The flour in the rhubarb mix acts as a thickener. We use all-purpose flour, but for the pastry and the filling.
• Instant tapioca: Tapioca also acts as a thickener in the filling. Use instant tapioca, not the larger tapioca pearls.
• Butter: We use salted butter, but unsalted butter is fine too.
• Pie crust: You will need one 9½-inch double-crust pie shell, or two standard 8-inch double-crust pie shells. You can use a homemade pie shell, or prepackaged refrigerated or frozen pie crust.

• Egg (optional): The egg is for an egg wash for the top of the pie: it is totally optional. The purpose of an egg wash is to give the pastry a golden, slightly shiny finish. An egg wash can make your pie look finished. (I often skip the egg wash and no one has ever complained.)

How to Make Rhubarb Pie from Scratch

Prepare the Pie Shell

You can use any pie crust you want for this pie. However, if you want to make your own dough (and I strongly encourage you to do so), our sweet pie dough recipe is tender, flaky, and easy to make.

Homemade Pie Dough

1. Chill pie plate in refrigerator for 30 minutes before beginning.
2. Take the pie plate, along with one half of your pie dough out of the refrigerator. (Continue to chill the other half.)
3. Roll out bottom crust and line pie dish, leaving at least 1½-inch overhang of dough on the edge.
4. Put rolled bottom crust in freezer for 5 minutes before proceeding.

Hint: I usually use about 60% of the pie dough for the bottom crust, and 40% for the top. That way, I can make the bottom crust ample enough to fold over the lattice to finish the pie.

Frozen Pie Shell

• Leave the bottom pie shell in the freezer until you are ready to fill it. Put the dough for the top in the refrigerator.

Make the Rhubarb Filling

Preheat oven to 425°F (218°C). Place the oven rack in the lowest or next to lowest position in the oven. Remove any racks above that may get in the way of the pie.

Remove any leaves and the root end of the stalk. Rinse under cold water to remove any dirt. Cut the stalks into ½ to ¾-inch pieces. Measure out 8-10 cups of cut rhubarb and set aside.

Whisk together the flour and sugar in small mixing bowl. Take the prepared pie shell out of the freezer and sprinkle ½ cup of the sugar-flour mixture over the bottom.

In a large bowl, toss together the cut rhubarb with 2 cups of the sugar-flour mixture and the tapioca. (For frozen rhubarb, include any liquid.)

Heap the rhubarb mixture into the pie shell. Sprinkle the remaining sugar-flour mixture over the top, and dot the top with butter.

Add the Top Crust

Remove dough for top crust from refrigerator, and roll it out on a lightly floured board.

Add a top crust to the pie as desired. A lattice top works well for rhubarb pie: if you use a solid top crust, be sure to cut some good-size vents.

Fold the 1½-inch dough overhang up and over the top crust or lattice, and crimp the edge to seal. (Sealing the edge this way will alleviate some of the boil-over drips for which rhubarb pie is famous.)

If your pie dough seems saggy or too warm when you get done adding the top crust, put the whole thing back in the freezer for 5 minutes.

Optional egg wash: Use a fork to whisk together one large egg and one tablespoon of water. Use a pastry brush to gently apply the egg wash to the top of the pie.

How Long to Bake Rhubarb Pie

Bake the pie on the lowest or next to lowest oven rack position, at 425°F (218°C) for 15 minutes.

Reduce oven to 375°F (190°C) and continue baking for 40-45 minutes (deep dish) or 30-40 minutes (standard).

Rhubarb pie is done baking when the crust is light golden brown and the filling is bubbly. Allow the pie to cool before serving.

Baking times will vary somewhat, depending upon your pie dish, oven, and depth of filling.

Keep an eye on your pie after the first 30 minutes of baking to avoid burning. If the crust looks like it is browning too much before the pie is done, gently lay a sheet of plain, flat aluminum foil over the top of the entire pie to avoid over-browning the top. Do not press down or otherwise form the foil: just lay it gently, like a feather.

Hint: If you want to be sure it's done, use an instant-read thermometer and check that the filling reaches an internal temperature of 213°F (100°C).

Pro Tips for the Best Rhubarb Pie

Use Room Temperature Rhubarb

Rhubarb used for filling must be room temperature. Never use chilled rhubarb, or your filling will take too long to cook and your pie shell will burn before the filling is done. 

My Go-To Method for Preventing Pie Boil-Over

Cut the bottom crust larger enough so that, after you add the top crust, the bottom edge can be folded up over it and sealed, as shown in the image above. In my experience, this significantly cuts down on pie shell leakage around the edges. 

Bake It on the Next-to-Lowest Rack

The bottom crust of a pie takes longer to bake than the top because the filling acts as insulation, slowing down the heat transfer. This is especially true for fruit pies, which tend to have dense, moisture-rich fillings. Placing your pie on a lower oven rack gives the bottom crust a head start, helping it bake through evenly—while also reducing the chance of the top crust over-browning.

Ratios for Sugar & Thickeners

Here’s how to scale rhubarb pie filling by volume:

• For each cup of rhubarb, use:
  • 2 tablespoons of flour, or
  • 1 tablespoon of cornstarch, or 
  • 1 tablespoon of instant tapioca
• For every 5 cups of rhubarb, use:
  • 1 tablespoon of butter
  • 1¼ cups granulated sugar

You can adjust the amount of sugar based on the tartness of the rhubarb you use and your personal tastes. Add up to an additional ⅓ cup sugar if your rhubarb is very tart, or if you prefer your pies very sweet. 

Rhubarb Pie Variations

• Spiced Rhubarb Pie: Warm spices can add a little something special to rhubarb pie. Try adding a half-teaspoon of cardamom or ground ginger, or a teaspoon of cinnamon, to the flour-sugar mixture.
• Vanilla Rhubarb Pie: Add a teaspoon or two of vanilla to the pie mixture.
• Rhubarb with Orange Zest: Orange and rhubarb play together very nicely. Add a little orange zest to your pie with the sugar,

Best Pie Plates for Rhubarb Pie

After decades of pie-making, my recommendation for the best pie plate is either a Pyrex basic deep dish or Pyrex fluted deep-dish pie plate.

The transparent Pyrex allows you to visually check the crust for doneness, and its even heat conduction yields a crisp, uniform crust. The durable Pyrex material can be cut without scratching the dish, and slices release neatly from the pan.

How to Store Rhubarb Pie

Room Temperature & Fridge

Leftover Pie: Cover leftover pie with plastic wrap or in an air-tight container. Rhubarb pie can be stored at room temperature for 2 days or in the fridge for up to a week.

How to Freeze Rhubarb Pie (Baked or Unbaked)

Rhubarb pie freezes very well. My mom used to make a tart-cherry rhubarb pie that Mr B loved, and when we were young, she always kept an unbaked cherry rhubarb pie ready in the freezer so she could make one for him whenever he visited.

Baked Pie: When properly stored, fully baked rhubarb pie can be frozen for up to 3 months. To do this, first allow the pie to cool completely, then wrap it in plastic wrap and again in aluminum foil.

Unbaked Pie: Add ¼ cup of additional flour to the filling mix. Assemble the pie completely. Wrap twice in plastic wrap and then again in aluminum foil. Unbaked rhubarb pie can be frozen for up to 6 months.

To bake, thaw in the refrigerator, and then bake as instructed.

Rhubarb pie is delicious warm or cold; as is, or with a scoop of vanilla ice cream on the side.

More Sweet Pie Recipes

Pastry roses are ridiculously easy to make, and are an easy way to up your pie-making game!

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