Rhubarb Custard Pie

I never tire of rhubarb recipes like my almond rhubarb cake, rhubarb muffins, and strawberry rhubarb crisp. And I especially love the ones with happy memories attached. This Rhubarb Custard Pie recipe comes from my Grandma Renelt, and is my dad’s favorite rhubarb pie.

Because of the rich custard filling, this rhubarb pie is not as intensely tart as most rhubarb dessert recipes. The custard mixture is super easy to make and sets up so nicely for cutting and serving, similar to my rhubarb custard bars recipe.

This rhubarb custard pie is a delicious way to enjoy summer rhubarb in a beautiful, old-fashioned kind of way. I do hope you enjoy my grandma’s pie!

Ingredients For Custard Pie With Rhubarb

With just a few ingredients, this rhubarb custard pie filling is AMAZING! Here’s what you’ll need. Scroll to the recipe card for the exact measurements.

• Rhubarb – I use fresh rhubarb from our garden, but most grocery stores carry it in spring and summer. Trim the edible stalks and chop them into bite-sized pieces. Discard the poisonous leaves. You can also make this pie with frozen rhubarb, see below.
• Granulated sugar – Used to sweeten up that tart rhubarb and to help the custard thicken up.
• All-purpose flour – Add a little bit to help the custard set up.
• Large eggs – An essential ingredient in custard. You can leave the eggs whole for this recipe.
• Nutmeg – Just a bit adds a lovely warm flavor and fragrance. If you can freshly grate it, even better.
• Unsalted butter – For adding richness to the pie filling. Please don’t substitute butter with oil in this pie, as the flavor and texture won’t be the same.

Can I Use Frozen Rhubarb?

Yes! I get this question a lot with rhubarb recipes. And while I absolutely prefer fresh rhubarb, this pie does well with frozen rhubarb, too.

I aim to make most of my rhubarb recipes by mid-summer, to take advantage of the most tender stalks. I then preserve the rest as freezer jam, or I’ll freeze fresh rhubarb by chopping it and placing it in freezer-safe containers or baggies (you’ll find freezing tips and more in my Rhubarb 101 guide). To use frozen rhubarb for this pie, here’s what I suggest:

1. Thaw the frozen rhubarb.
2. Drain the rhubarb and pat it dry.
3. Then toss the rhubarb with a tablespoon of flour. This helps to absorb extra moisture.

The Perfect Pie Crust

And of course, let’s talk about pie crust. Like Grandma Renelt before her, Mom is a great pie maker, and she’s always relied on Betty Crocker’s pie crust recipe for desserts like her famous peach pie and this one.

It’s easy to make, easy to work with, and beautifully flaky. I’ve since adapted it into a homemade version for my cherry pie. I won’t go into depth about the pie crust here, but you can use that recipe or your own favorite homemade or frozen pie crust.

I weave a lattice crust as the top crust for my pie. If you’d prefer to skip the lattice and use a full crust, that’s perfect, too! Just be sure to cut a few vent holes in the top before baking, so the steam can escape.

How To Make Rhubarb Custard Pie

You will not believe how easy it is to make an unforgettable rhubarb custard pie.

1. Preheat the oven. Position your oven rack one level lower than the center of the oven. Then, preheat the oven to 350°F.
2. Make the pie crust. Follow Betty Crocker’s recipe (what my mom uses) or use your own favorite homemade or frozen pie crust. You’ll need a double crust: One to hold the filling and a second for the lattice top.
3. Add rhubarb to the bottom crust. Next, line a 9″ pie plate with the pie crust and spread chopped rhubarb over the bottom.
4. Create the custard. Now, stir together the sugar, flour, salt, and nutmeg in a bowl. Mix in the eggs. Pour the custard mixture over the rhubarb.
5. Dot with butter. Nothing fancy here. The butter will melt into the pie filling, so divide the butter into cubes and arrange it on top of the filling.
6. Top with lattice pie crust. Cut your second pie crust into strips to make a lattice top over the pie filling (follow the step-by-step in my cherry pie recipe). Then, brush the lattice strips with milk for prettier browning. Finally, sprinkle the crust with coarse sugar for a little extra sparkle and texture.
7. Bake. Last but not least, bake the pie at 350ºF for 45 to 60 minutes, or until the crust is nicely browned.

Tips for a Perfect Custard Pie

• Use cold ingredients in the pie crust. Most pie crust recipes call for chilled shortening or butter, plus ice water. Your pastry crust will be flakier and easier to work with if you chill these items.
• Choose the right rhubarb. Use the smaller stalks of rhubarb, and ones that are more red than green. The smaller stalks will be more tender, while the red color is just plain prettier in the pie.
• Bake on a lower rack. I’ve taken after my mom and bake my pies just a bit lower than the center of the oven. This way, the crust bakes up firmer.
• Brush with milk. Brushing the top of the pie pastry with a bit of milk helps to add a pretty browned effect with a little shine. You can also brush the crust with a beaten egg or egg yolk mixed with a teaspoon of water, which lends a more glazed appearance.
• Sprinkle with sugar. After brushing the top crust with milk, add some sugar. This adds a little sparkle, plus a fun texture. While you can use plain granulated sugar, I much prefer sanding sugar or similar.

How To Store Rhubarb Custard Pie

I like to make pie when I know all or most of it will be eaten on the same day it’s made. It’s flakiest and most tender then, at its utmost enjoyable best! When some pie remains, I do refrigerate the leftovers. Cover the pie tightly in plastic wrap and keep it in the fridge for up to 3 days.

Memories of Grandma Renelt