Rhubarb Custard Pie Recipe (Old-Fashioned & Easy)

Prep Time: 25 minutes | Cook Time: 55 minutes | Total Time: 1 hour 20 minutes Servings: 6–8

If you’ve ever tasted a real, from-scratch rhubarb custard pie, you already know why people get downright giddy when rhubarb season rolls around. If you haven’t tried it yet — oh, are you in for a treat!

This is Mom’s recipe, and it’s one of those old-fashioned pies that tastes like a hug from someone who really loves you. The filling is thick, creamy, sweet, and just tart enough to keep things interesting. And that buttery lattice crust on top? Pure magic. Every single time.

The best part? You only need 8 ingredients and about 25 minutes of prep. The oven does the rest.

What Is Rhubarb Custard Pie?

A rhubarb custard pie is different from a regular fruit pie. Instead of a simple fruit filling thickened with cornstarch, this pie uses an egg custard — eggs beaten with sugar and flour — that bakes up thick, rich, and creamy around the tart rhubarb pieces.

The result is somewhere between a fruit pie and a creamy custard tart. It’s not eggy or too sweet. It’s just really, really good.

This is a very traditional pie in many parts of the Midwest. For a lot of us, it’s pure comfort food that takes you straight back to grandma’s porch in summer.

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How to Choose Fresh Rhubarb

When rhubarb season arrives in the Midwest — usually starting in April and running 8 to 10 weeks — I snatch up as much as I can find at the farmers market and the grocery store.

Here’s what to look for when picking rhubarb:

Choose stalks that are: firm, crisp, shiny, and 12 to 18 inches long. Those are ripe and ready to use.

Skip stalks that are: soft, limp, or have blemishes. Those are past their prime.

Once you get it home, store fresh rhubarb stalks in a sealed plastic bag in the refrigerator — and don’t cut them until you’re ready to use them. Rhubarb dries out fast once it’s cut.

Can’t use it right away? Just slice it up and freeze it in an airtight container. It keeps beautifully and is ready to go whenever you need it.

One quick note: Never eat the leaves. The leaves of the rhubarb plant are poisonous. Use only the stalks.

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Ingredient Tips for the Best Rhubarb Custard Pie

Here’s a closer look at the ingredients that make this pie so good:

Fresh Rhubarb is the star of the show here. You’ll need about 3 cups (roughly 1 pound), cut into 1-inch pieces. Fresh rhubarb gives you the best flavor and keeps the filling from getting watery. If you use frozen rhubarb, thaw it completely and press out as much moisture as you can before adding it to the filling.

Eggs give this pie its creamy custard texture. We use 3 large Grade A eggs for the filling, plus 1 more for the egg wash on the crust. Room temperature eggs blend a little more smoothly into the filling.

Sugar balances out the tartness of the rhubarb. We use 1½ cups of plain white granulated sugar. If your rhubarb is on the really tart side, you can nudge that up by a couple of tablespoons.

Flour is what thickens the custard so it sets up properly. Just ¼ cup of all-purpose flour does the job beautifully.

Cinnamon adds a warm, cozy flavor that complements the rhubarb perfectly. A pinch of nutmeg is a nice optional addition too — you’ll find it in a lot of old-fashioned versions of this recipe.

Butter is dotted over the top of the filling before you add the crust. It melts down into the filling as it bakes and makes everything taste extra rich and buttery. Don’t skip it!

Pie Crust — I love my homemade All-Butter Pie Crust for this recipe. It’s flaky, buttery, and makes the best lattice top. That said, a good store-bought double crust works just fine if you’re short on time.

Coarse (turbinado) sugar sprinkled on top of the lattice crust before baking gives it a gorgeous sparkle and a little crunch. Regular white sugar works too — it’s what Mom always used!

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Pro Tips for a Perfect Pie Every Time

After making this pie more times than I can count, here’s what I’ve learned:

Use fresh rhubarb whenever you can. It keeps the filling from turning watery. If using frozen, thaw and squeeze out the extra moisture.

Fold the rhubarb in gently. You can use a stand mixer or hand mixer for the custard base, but add the rhubarb by hand with a spoon or spatula. You want the pieces to stay whole, not get mashed up.

Set your pie on a baking sheet lined with parchment paper. That filling can bubble over as it bakes. This saves your oven floor!

Use the whole egg for the egg wash (not just the whites). The full egg gives the crust a beautiful golden-brown color as it bakes.

Apply the coarse sugar right away while the egg wash is still wet. If it dries before you add the sugar, it won’t stick.

Watch the edges of your crust. If they start to get too dark before the filling is set, tent some aluminum foil loosely over the edges for the last 10 minutes.

Know when it’s done: Slide a butter knife into the center of the pie. If it pulls out with thick filling on it, you’re good. If the filling is still thin and watery, bake a little longer.

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How to Make a Lattice Crust (Step-by-Step)

The lattice crust is what makes this pie look like it came straight out of a magazine — and it’s so much easier than it looks! Here’s how to do it:

1. Roll out your top crust on the back of a baking sheet (this keeps it from sticking and makes it easy to pick up the strips). Roll it to about 11½ to 12 inches across.
2. Cut into strips about ½ inch wide using a knife or a ravioli cutter. The wavy edge from the ravioli cutter gives the lattice a pretty, old-fashioned look.

3. Lay the longest strip down the center of the pie, running vertically. Add more strips parallel to it, about 1 inch apart, until you reach both edges.
4. Lift every other vertical strip and lay one horizontal strip across the middle of the pie. Lay the lifted strips back down, then lift the alternating strips and lay the next horizontal strip. Keep going until the whole top is covered.
5. Trim the overhang, then tuck the ends of the strips under the bottom crust edge and flute or crimp to seal.

Don’t want to mess with the weaving? No problem — just cut slits in a solid top crust and it’s just as delicious!

(Check out the video in this post to see the lattice steps in action!)

How to Make Rhubarb Custard Pie (Step-by-Step)

Making this pie is easier than you might think! Here’s exactly how to do it, start to finish.

Step 1: Preheat and Prep Preheat your oven to 400°F. Line a 9-inch pie plate with your bottom pie crust and set it aside. Go ahead and slice your rhubarb into 1-inch pieces now so it’s ready to go.

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Step 2: Mix the Dry Ingredients In a large mixing bowl, whisk together the sugar, flour, cinnamon, and salt until combined. This only takes about 30 seconds — you just want everything evenly mixed.

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Step 3: Add the Eggs Beat 3 eggs and pour them into the dry ingredient mixture. Stir or whisk everything together until the mixture is smooth and creamy. It will look a little like a thick cake batter. This is your custard base!

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Step 4: Fold in the Rhubarb Using a spoon or spatula, gently fold the sliced rhubarb into the custard mixture. You want to stir just enough to coat all the rhubarb — don’t over-mix or mash the pieces.

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Step 5: Fill the Pie Shell Pour the rhubarb custard filling into your prepared pie crust. Spread it out evenly so you get rhubarb in every bite. Then dot the top of the filling with small pieces of butter — this melts in as the pie bakes and makes the filling extra rich.

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Step 6: Add the Lattice Crust Follow the lattice crust instructions in the section above to weave your top crust. Once the lattice is on, make your egg wash by whisking 1 egg with 1 teaspoon of water. Brush it over the lattice strips, then immediately sprinkle with coarse sugar before the wash dries.

Don’t want to do the lattice? Just lay a full crust on top, crimp the edges to seal, and cut 4 to 6 slits in the top so steam can escape.

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Step 7: Bake Place the pie on a parchment-lined baking sheet (trust me on this — it can bubble over!). Bake at 400°F for 20 minutes, then reduce the oven temperature to 350°F and bake for another 35 to 40 minutes.

The pie is done when the crust is deep golden brown and a butter knife inserted into the center comes out with thick filling — not thin or watery. If the crust edges start getting too dark, tent them loosely with aluminum foil.

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Step 8: Cool Before Slicing Let the pie cool for at least 1 to 2 hours before cutting into it. The custard filling needs time to set up fully. I know — the hardest part is the waiting! But it’s worth it for clean, beautiful slices.

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How to Serve Rhubarb Custard Pie

This pie is wonderful served slightly warm or at room temperature. Here are a few of my favorite ways to enjoy it:

With a scoop of vanilla ice cream. This is the classic pairing, and it’s classic for a good reason. The cool, creamy ice cream is perfect next to that sweet-tart rhubarb filling.

With a dollop of fresh whipped cream. Light and airy, it doesn’t compete with the flavors of the pie at all.

Plain, straight from the plate. Sometimes a really great pie doesn’t need a single thing added to it. This is one of those pies.

This pie is a natural fit for spring and summer gatherings, Mother’s Day dessert tables, potlucks, and holiday dinners. It always gets compliments — and people are always a little surprised that the filling is so rich and creamy. It’s a great conversation starter!

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How to Store and Freeze Rhubarb Custard Pie

In the refrigerator: Because of the egg custard filling, this pie should be refrigerated after it cools. It will keep well for up to 3 to 4 days in the fridge. Refrigerating also helps keep the filling from getting watery or the crust from getting soggy. Cover it loosely with plastic wrap or foil.

Reheating: You can warm individual slices in the microwave for about 20 to 30 seconds, or warm the whole pie in a 300°F oven for 10 to 15 minutes. It’s also great cold, straight out of the fridge!

Freezing: Yes, this pie freezes! Let it cool completely, then wrap it tightly in plastic wrap and place it in an airtight freezer bag or container. It keeps for up to 3 months in the freezer.

To thaw: Move the pie to the refrigerator the night before you plan to serve it and let it thaw slowly overnight.

Make-ahead tip: You can bake this pie a day ahead and refrigerate it overnight. Just let it come to room temperature or warm it gently before serving for the best texture.

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Fun Variations to Try

Add a pinch of nutmeg to the custard filling along with the cinnamon. It gives the pie a warm, slightly spiced flavor — very cozy and old-fashioned.

Swap the lattice for a crumble topping. Mix ½ cup of flour, ½ cup of brown sugar, ¼ cup of rolled oats, and ¼ cup of cold butter (cut into pieces) until crumbly. Sprinkle over the filling instead of the top crust. It bakes up golden and crunchy — like a cross between a pie and a crisp!

Try it with frozen rhubarb in the off-season. Thaw completely, press out the moisture, and you can enjoy this pie any time of year.

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Related Rhubarb Recipes You’ll Love

If you’re on a rhubarb kick (and once you start, you really can’t stop!), here are some more recipes you’ll want to make:

Strawberry Rhubarb Pie — This is Grandma’s recipe, and it is a stunner. Sweet, juicy strawberries and tart rhubarb piled high in a buttery double crust. It’s a completely different pie from this one — more fruit-forward and no custard — so if you love this one, you need to try that one too.

Apple Rhubarb Skillet Pie — Made in a cast iron skillet over a layer of buttery caramel, this one is like a cozy fall dessert with a spring twist. The apples mellow the tartness of the rhubarb and the caramel layer underneath is everything.

Rhubarb Crunch — No crust required! This easy baked rhubarb dessert has a sweet rhubarb filling topped with a buttery oat crumble. It’s perfect for when you want something delicious without all the pie crust work.

Rhubarb Muffins with Cinnamon Butter Crumble — These are one of our most popular recipes on the whole blog, and for good reason. Moist, tender muffins loaded with rhubarb and topped with the most irresistible crunchy cinnamon crumble. Perfect for breakfast or a snack.

Rhubarb Sauce — If you have extra rhubarb after making your pie, don’t waste it! This smooth, silky sauce is amazing drizzled over ice cream, spooned over pork chops, or spread on toast like jam.

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FAQ: Rhubarb Custard Pie

Can I use frozen rhubarb for this pie? Yes! Thaw it completely and then press the excess moisture out with paper towels before adding it to the filling. Frozen rhubarb holds a lot of water, so this step keeps your filling from getting watery.

Why does my rhubarb custard pie turn out watery? The most common reason is using frozen rhubarb without draining it well, or pulling the pie out of the oven before it’s fully set. Make sure to bake until a butter knife inserted in the center comes out with thick filling — not thin, runny liquid.

Do I have to use a lattice crust? Not at all! A solid top crust with a few slits cut in it works perfectly. The lattice is just a pretty, old-fashioned touch that shows off that gorgeous filling.

Is rhubarb custard pie supposed to be refrigerated? Yes. Because the filling contains eggs, this pie should be refrigerated once it’s cooled down. It keeps for 3 to 4 days in the fridge.

What does rhubarb custard pie taste like? It’s sweet and creamy from the custard, with a pleasant tartness from the rhubarb. It’s richer and creamier than a regular fruit pie, but not as dense as a traditional egg custard. If you’re worried it might taste eggy — it doesn’t! Mom’s recipe is smooth and creamy, nothing like scrambled eggs.

Can I make this pie ahead of time? Yes! This pie is actually great made a day in advance. Bake it, let it cool completely, then refrigerate it overnight. The filling firms up nicely as it chills.

Do I need to peel rhubarb? Nope! Just trim the ends and cut the stalks into 1-inch pieces. No peeling required.

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Make This Your New Spring Tradition

Mom’s Rhubarb Custard Pie has been a part of my family for as long as I can remember, and I hope it becomes part of yours too. There’s something really special about a homemade pie — especially one made with a ingredient as unique and wonderful as rhubarb. That creamy, sweet-tart custard filling in a flaky, golden lattice crust is just impossible to resist.

If you give it a try, I would love to hear how it turned out! Drop a comment below and — if you loved it — please leave a ⭐⭐⭐⭐⭐ rating. Those ratings really help other readers find this recipe, and I’m so grateful for each one!

Did you enjoy this recipe? Don’t forget to pin it for later and follow me on Pinterest for more delicious recipes like this one!

Originally published: July 9, 2021. Updated: March 19, 2026– Enhanced with more detailed instructions, tips, and serving suggestions. No changes were made to the recipe.