Name: Rhubarb Custard Pie Recipe
Prep time: 5 min
Cook time: 10 min
Ingredients: 1 frozen store-bought pie crust in a pie plate; 1 large egg white; 1 teaspoon water; pinch of kosher salt; 1 pound (or 454 grams) fresh rhubarb, sliced into ½-inch chunks; 1 ½ cups (10.5 ounces or 298 grams) granulated sugar, divided into ¼ cup (1.75 ounces or 50 grams) and 1 ¼ cup (8.75 ounces or 248 grams) portions (see baker's notes); ⅓ cup (1.5 ounces or 43 grams) all-purpose flour; 2 large eggs; 4 Tablespoons (2 ounces or 57 grams) unsalted butter, melted; ¼ cup (4 ounces or 113 grams) heavy cream

About This Rhubarb Custard Pie

Most American rhubarb pie recipes are plain and simple—just tangy rhubarb fruit encased in buttery pie crust. While plain old rhubarb pie is still a pretty good dessert, I wanted to take my rhubarb pie to the next level. What does that mean? I combined the tart and tangy rhubarb fruit with a sweet cream custard to make this beautiful rhubarb custard pie!

However, I’m not actually the innovator of this particular flavor combination. British recipes frequently pair rhubarb and custard together in desserts. Indeed, over the years, I’ve watched many Great British Bake-Off contestants whip up beautiful rhubarb custard desserts. And I have fond memories of watching one of my British friends whip up a rhubarb custard frangipane galette for a dinner party.

@hummingbirdhigh i was serious the other day when i said i just want to make #pie all day every day #bakingrecipe #baking #bakingtiktok ♬ The Great British Bake Off – Tom Howe

But hold the phone. What exactly is rhubarb, anyway?

What is rhubarb?

Rhubarb is a long, thin vegetable that looks a little bit like celery. Both celery and rhubarb are sold as stalks. However, unlike celery, rhubarb is know for its distinct pink color. That being said, rhubarb comes in a range of colors. Some stalks have pale greenish-pink hues, while others range from stronger pastel pinks to deep, magenta reds.

Wait—you said rhubarb is a vegetable. Is rhubarb a fruit or a vegetable?

Yes, technically, rhubarb is a vegetable. Why? Botanically speaking, fruits are the result of seed-bearing plants, whereas vegetables come from other plant parts like roots, leaves, and stems. And culinary rhubarb comes from the stem of a rhubarb plant (Not the leaves though—those are inedible and poisonous! We’ll get to that in a second).

That being said, rhubarb is technically classified as a fruit. What does that mean, exactly? According to this Huffington Post article, in 1947, a New York court declared rhubarb a fruit for tax-saving purposes. Back then, importers of fruit were charged less taxes than importers of vegetables. Lawyers successfully argued that rhubarb should be declared as fruit because rhubarb most often used and prepared in sweet dishes. Wild, right?

I’m still distracted about what you said about rhubarb being poisonous. Is rhubarb poisonous?!

Hahaha, yep, parts of the rhubarb plant are poisonous! Specifically, rhubarb leaves contain high amounts of oxalic acid, which can cause kidney failure in humans. Eating even a small amount of rhubarb leaves can cause diarrhea and vomiting. Yikes.

Thankfully, the part of the rhubarb plant that we eat and use for baking and cooking—the stem—is safe and sound. Just be sure that, if you purchased fresh rhubarb for this recipe, you trim off any leaves as well as the top of the stalk before using!

What does rhubarb taste like?

Uncooked, raw rhubarb is VERY tart, sour, and acidic. Like, almost inedibly so. As a result, almost all recipes instruct you to cook the rhubarb and serve it with a generous amount of sugar. Even after the fact, rhubarb retains a lot of its tartness. I like to think of its flavor as similar to tart green apples or unsweetened cranberry juice… but also not really, lol. Rhubarb definitely has its own flavor that’s worth trying!

What Does Rhubarb Custard Pie Taste Like?

Because if its tart flavor, rhubarb works really well with sugar and dairy. Like in this rhubarb custard pie!

Without the rhubarb, the sweet cream custard tastes like a traditional buttermilk chess pie. But because this pie is made with cream instead of buttermilk, it lacks any kind of tangy, acidic flavor. Think of it as similar to vanilla ice cream, but baked in a buttery pie crust shell. Sounds delicious but intense, right?

Enter the rhubarb fruit topping! The rhubarb acts like the buttermilk in traditional chess pie recipes and brings tart, tangy flavors to the whole pie. Without the rhubarb, the sweet cream custard filling would be too rich on its own.

Does classic rhubarb custard pie have a top crust?

No, I don’t think so? When researching different rhubarb custard pie recipes to try for this post, I noticed that 9 out of 10 of them didn’t have top crusts. I suspect it has to do with the custard—other custard based pies like chess pies, key lime pies, and more rarely have top crusts, either.

That being said, I did see a handful of recipes that made the pie with a top crust. Upon close inspection though, it seemed like these pie recipes were more akin to traditional rhubarb pies than rhubarb custard pies? I don’t know, you do you. I’m sure a top crust would be delicious!

Why You Should Make The Recipe

Here are all the reasons why you should make this rhubarb custard pie recipe:

This recipe comes together quickly.

Thanks to the store bought crust, this rhubarb custard pie recipe is fast and easy. Beyond baking the pie crust and the assembled pie itself, all you really need to do is chop up the rhubarb and make the custard filling. And those tasks only take 10 minutes… combined! Crazy, right?

This recipe is from a trusted source: Martha Stewart!

Contrary to popular belief, I do not develop all the recipes on this blog from scratch. Some are from other sources—usually cookbooks, magazines, and other food blogs—that I’ve wanted to try for myself. Like this rhubarb custard pie recipe! This particular recipe comes from the queen herself, Martha Stewart. And of course, because Martha is Martha, it’s absolutely delicious and does not disappoint.

This rhubarb custard pie has ingredients that can be easily substituted with other similar ingredients.

One of the reasons why I was drawn to this rhubarb custard pie recipe in the first place was because I noticed that its ingredients were extremely adaptable. What does that mean? In theory, if you find yourself missing a certain ingredient, you can easily swap it out for something that you already have on hand. This will prevent you from having to make a last minute run to the grocery store, and encourage you to make do with what you have in your pantry. Be sure to check out the ingredients section below for all my substitution recommendations!

Ingredients and Substitutions

Now that I’ve convinced you to make this rhubarb custard pie recipe, here’s your shopping list for the recipe:

Shopping List for Rhubarb Custard Pie Recipe

frozen store-bought pie crust (preferably in a pie plate)
large eggs
kosher salt
fresh rhubarb
granulated sugar
all-purpose flour
unsalted butter
heavy cream

And let’s talk about some of its key ingredients and potential substitutions:

Store-Bought Pie Crust

This rhubarb custard pie recipe uses a store-bought pie crust for its pie crust base.

Types of store-bought pie crust

Typically, grocery stores sell two different types of store-bought pie crust. The first kind is where the dough is rolled up in a sheet, and you need to do the work of fitting it onto the pie plate yourself. The second kind is where the dough is already molded onto a pie plate (usually one made of disposable aluminum), and all you need to do is fill it. Depending on the brand, you end up with either an 8-inch or 9-inch pie. For this rhubarb custard pie recipe, I used the latter kind where the pie dough has already been fitted into a plate.

Why use store-bought pie crust?

As much as I ~~hate~~ love making pies from scratch (I mean… remember that time I spent the year making a different kind of pie per month?), I recently finished Nadiya’s Time to Eat on Netflix and was inspired to make this recipe more accessible.

In the show, the lovely host Nadiya Hussein (and winner of The Great British Bake-Off in 2015) teaches time-poor families and individuals on how to cook tasty and delicious meals quickly and on a budget. Despite being one of the UK’s most talented bakers, Nadiya actively encourages folks to use store-bought shortcuts like premade pastry dough, canned fruits and vegetables, and more. That way, folks could still end up with delicious, beautiful meals without spending hours in the kitchen.

I was inspired by how accessible Nadiya’s recipes were and decided to stop being so snotty about making pie dough from scratch. Indeed, with a store-bought pie crust, this recipe came together SO quickly. Like… seriously. I think it took less than 5 minutes to prep the pie dough for the filling, and another 5 minutes to make the filling itself? The rest of the time was spent waiting for the pie to finish baking in the oven!

Best store-bought pie crust

Confession: I am not the best person to answer this question. I always use the generic store-bought pie crust from Safeway because I like the way they crimp its edges (they look like these ones from Marie Callender’s). But is it the best tasting? I really don’t know. Instead, I encourage you to check out these articles from Epicurious and The Kitchn that compare different store-bought pie crusts under the same filling.

How to make store-bought pie crust better

Okay, so you read the last few paragraphs above and are looking at me with disbelief. But store-bought pie crust is so bad, I hear you thinking. Why are you making me do this?! I admit: it’s hard to compare store-bought pie crust to homemade flaky, all-butter pie dough made from scratch. But here’s the thing—good recipes transcend bad ingredients. That is, an amazing pie filling like this rhubarb custard will cover up a mediocre pie crust.

And besides, there are a lot of tips and tricks to make store-bought pie crust better. The crazy talented Shauna Sever likes to pulse up cookie crumbs and add them to the dough for an extra layer of crunchiness. And in this recipe, I instruct you to ignore the manufacturer’s instructions for pre baking the pie crust. Why? My method results in an infinitely crisp pie crust with no soggy bottom. But we’ll learn more about that in a second.

Can I make this rhubarb custard pie recipe with store-bought gluten-free pie crust?

Yes, absolutely! But note that the filling itself is not actually gluten-free. The custard filling uses ⅓ cup all-purpose flour. Check out the flour section below to read about possible substitutions and ways to potentially make it gluten-free.

Also note that I have never pre baked a store-bought gluten-free pie crust before. My instructions for pre baking might not work for the gluten-free pie crust. You may want to stick with the manufacturers’ instructions for pre baking instead.

Can I make this rhubarb custard pie recipe with homemade pie crust from scratch?

Yes, absolutely! If you’re looking for an easy, all-butter homemade pie crust recipe to use for this rhubarb custard pie, I recommend checking out the one in my cookbook, Weeknight Baking and this post on How To Make Pie Crust In A Stand Mixer. It’s seriously my best and favorite recipe for pie dough. I instruct you to make the pie dough in a stand mixer like you would a sugar cookie dough to bring it together. It’s much easier than fussing around with a pastry cutter or hauling out your food processor for the job!

Intrigued? You can see a sneak peek of the recipe in this recipe for chocolate chess pie.

Rhubarb

This rhubarb custard pie recipe uses 1 pound fresh rhubarb.

Can I use frozen rhubarb?

Yes! You can use frozen rhubarb in this rhubarb custard pie recipe. As long as the rhubarb has been sliced into ½-inch pieces, there’s no need to even thaw the frozen rhubarb before using in this recipe!

However, if you make this pie with frozen rhubarb, it’s likely that you’ll need to add 5 to 10 minutes to the Bake Time to fully cook the cold fruit.

How to Freeze Leftover Rhubarb

Uh oh, you bought too much rhubarb and now have some left over. No worries—rhubarb freezes wonderfully! Before freezing, I like to clean the fruit thoroughly. I then slice the rhubarb stalks into ½- to 1-inch pieces. Why? It’s very rare that recipes—especially baking recipes—use whole rhubarb. Many recipes call for the rhubarb to be sliced into ¼-, ½-, and 1-inch pieces. After slicing the fruit, transfer it to a freezer zip top bag. Squeeze all the air out of the bag and freeze for up to 1 year.

Now… what can you do with that frozen rhubarb? Good question! Check out the bottom of the blog post for links to other rhubarb recipes on my blog!

Can I use another fruit besides rhubarb for this rhubarb custard pie recipe?

Yes! You can either swap out part of the rhubarb with another fruit (like strawberries, to make a strawberry rhubarb pie!), or replace it completely. However, some fruits will work better than others. I suggest swapping the rhubarb out with a berry—I recommend strawberries, blueberries, and raspberries. I do not recommend any kind of stone or stem fruit. Their flavors and textures won’t work as well with the custard base.

How to Make Rhubarb Custard Pie

Here are the basic steps to make rhubarb custard pie from scratch:

First, prep the main ingredients:

Pre bake the store-bought pie crust. (Bake Time: 30 minutes)
When a recipe instructs you to pre bake a pie crust, that usually means that the pie’s crust and filling have different baking times. You can learn more about the process in my blog post on How To Pre Bake Pie Crust.
While the crust is in the oven, prep the rhubarb. (Prep Time: 5 minutes)
While the crust is baking in the oven, I like to prep the rhubarb by cleaning and slicing it for use in the filling. I then toss the rhubarb in ¼ cup of granulated sugar. Why? The sugar encourages the rhubarb to soften and release some of its fruit juice, making it more flavorful and toothsome. This process is called maceration. Cool, right?

Next, make the custard filling:

Once the pie crust is done pre baking, make the custard. (Work Time: <5 minutes)
Assemble the pie. (Work Time: <5 minutes)
Bake the pie. (Bake Time: 60 minutes)

Recipe Troubleshooting and FAQ

FAQ: Questions About Ingredients

Can I make this rhubarb custard pie recipe gluten-free?

Yes! You can make a gluten-free rhubarb custard pie with this recipe. Simply use the gluten-free store bought pie crust of your choice. You may need to pre bake the pie crust to the manufacturers’ instructions since I don’t know if my instructions below work for gluten-free pie crusts. Then, make the filling, but use 5 tablespoons of cornstarch (or potato or tapioca starch) instead of all-purpose flour.

FAQ: What Equipment You Need To Make Rhubarb Custard Pie

What are pie weights and why do I need to use them in this rhubarb custard pie recipe?

This rhubarb custard pie recipe instructs you to cover the unbaked pie crust with aluminum foil, then pour in pie weights on top of the foil and bake the whole thing. The pie weights weigh the pie crust down as it bakes, preventing any air bubbles underneath the pie crust to rise up and cause weird bumps in the crust. The pie weights also weigh down the dough so that it holds its shape and stays molded onto the pie plate as it bakes. Without them, your pie crust will likely shrink and sag down the pie plate.

You can learn more about pie weights and what you can use as a substitution for them in my blog post on How To Pre Bake Pie Crust.

FAQ: How to Store Rhubarb Custard Pie

Can you freeze an unbaked rhubarb custard pie?

Sadly, no. It’s best not to freeze unbaked cream or custard pies. The cream and custard fillings tend to get watery and separate as they thaw. Let’s avoid that, please!

Does baked rhubarb custard pie need to be refrigerated?

Yes! Because the filling is cream-based, I suggest refrigerating this pie. After baking, I like to let the pie cool completely. Doing so will crisp up the crust and firm up the custard pie filling perfectly. After that, I cover with a loose sheet of plastic wrap and refrigerate for up to 3 more days.

Can baked rhubarb custard pie be frozen?

Yes! Follow the recipe instructions for cooling the pie completely to room temperature. After that, tightly wrap the entire pie (or any leftovers!) in two layers of plastic wrap and freeze for up to 3 months.

To serve, thaw overnight in the refrigerator. Serve chilled, or reheat in the microwave or by baking in the oven at 350°F for 10 to 15 minutes or until a knife inserted into the center of the filling comes out warm.

Best Rhubarb Custard Pie Recipe Tips

Time Saving Tips

If 1 ½ hours of Bake Time sounds like too much time to sit around and wait, you can split the recipe up over a few days! On Day 1, pre bake the pie crust according to the recipe. Instead of filling it, let it cool completely to room temperature. Store overnight on the counter under a cake dome or a large bowl upside down. On Day 2, follow the instructions for making the rhubarb custard pie filling and baking the assembled pie.

What’s the point of doing this? Breaking the recipe down this way allows you to fit it more easily into your schedule. That means no sitting around for hours at a time to wait for something to finish baking! Cool, right? If this sort of time-saving cooking technique appeals to you, I highly encourage you to check out my cookbook, Weeknight Baking. I break down common time-intensive recipes in this way!

Ingredient Tips

Rhubarb is listed in the recipe by weight, not volume or size. Why? It’s risky not to include exact measures for fruit in baking recipes. Too little fruit and your baked good could potentially turn out dry and flavorless, while too much will cause your baked good to collapse in the center. This is especially important for recipes where the fruit is baked into the batter like banana bread. That being said, there’s more leeway with this rhubarb custard pie recipe. If you are more comfortable with using cup measures, note that this rhubarb custard pie recipes needs about 4 cups of rhubarb sliced into ½-inch chunks.
Note that you’ll need to divide the sugar into two quantities: ¼ cup and 1 ¼ cup portions. The first ¼ cup is used to prep the rhubarb, while the remaining 1 ¼ cup is used to make the custard filling.

Baking Tip

When done, the rhubarb custard pie filling will be golden brown around the edges, but light in the center. Check the pie 45 minutes into its Bake Time. If the center is browning too quickly, cover with a loose piece of aluminum foil.

Video Tutorial for Rhubarb Custard Pie Recipe

Use the video player below to watch my Instagram Story tutorial on how to make this rhubarb custard pie recipe! The arrows to the left and right of the frame allow you to skip through the different recipe steps. You can also hit the “pause” or “enlarge” buttons on the upper right hand side of the frame to pause or enlarge the frames accordingly.

Alternatively, head to my Instagram profile to watch these Stories on mobile! The circles underneath my bio indicate saved Instagram Story highlights depicting various recipes. Clicking on one of the circles will play the videos you see above. You may need to scroll right to find this rhubarb custard pie recipe.

More Rhubarb Recipes

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