Grandma’s Rhubarb Pie Recipe: Ingredients And Preparation

In this article, you’ll find out just how rhubarb can be turned into a delicious dessert full of tart sweetness that people love. Learn more about rhubarb’s history, nutritional value, and best recipes here.

Rhubarb Pie is the perfect amount of sweetness between two pie crusts, and the filling is only 5 ingredients. This recipe comes straight from our Grandma’s recipe box.

Grandma’s Rhubarb Pie Recipe

Our Dad loves this old fashioned rhubarb pie. We don’t blame him, because it is perfection. If mom or I haven’t already made one, he will conveniently cut some rhubarb and leave it in the kitchen. Next thing you know, a rhubarb pie appears.

This is a pretty unique rhubarb pie recipe.  Most often, you’ll see rhubarb and strawberry pie.  We prefer this version, hands down.

Please note—rhubarb varieties vary in color. Some are more green, while others have a vibrant red of pink.

Our rhubarb plant at home is more green in color while the frozen rhubarb we purchase in the freezer department is more pink. This changes the color of the pie filling vastly; however, they are all beautiful and delicious.

Old Fashioned Rhubarb Pie Ingredients

• Diced rhubarb, fresh or frozen (1 inch pieces)
• Pie Crust
• Vanilla
• Large Egg
• All Purpose Flour
• Granulated Sugar

The filling is easy. Rhubarb, sugar, flour, egg and vanilla. Grandma would make a mixture of the cut rhubarb, sugar and flour. Then she’d make a separate mixture of egg and vanilla. Lastly, she’d combine the two mixtures and pour into a pie crust.  Simple enough!

How to make Grandma’s Rhubarb Pie

Step by Step Instructions

1. Preheat the oven. Line pie pan with prepared crust.
2. Wash and cut rhubarb stalks into chunks.
3. Add flour and sugar to rhubarb. Mix.
4. In a separate bowl, add egg and vanilla. Whisk with fork.
5. Combine rhubarb and egg mixtures.
6. Add rhubarb filling to pie crust.
7. Arrange second pie crust over top of pie. Seal the crust.
8. Cook for 15 minutes at 425 degrees F. Reduce oven temperature to 350 degrees F and cook for additional 45 minutes.
9. Let pie rest before serving.

Full recipe directions and ingredient amounts for frozen or fresh rhubarb are at the bottom of this post in the recipe card.

What is Rhubarb?

Are you familiar with rhubarb?  It’s a vegetable that once planted, returns each year. Typically, it’s one of the first signs of spring around here in Indiana (that and our asparagus patch).  Rhubarb grows long stalks that are red and green with big leaves.

Be sure to remove the rhubarb leaves before cooking because they are poisonous. When you find it at the grocery story, the leaves are usually removed for you!  The stalks are completely edible; however, they are very tart. That’s why most recipes use rhubarb as a dessert with plenty of sugar.

We use rhubarb many different ways such as Grandma’s Rhubarb Streusel, Rhubarb Muffins and Rhubarb Bread. We gathered some of our favorite recipes and those of our friends in the rhubarb post. This pie recipe is actually the rhubarb recipe Grandma made most often.

Crust Options

The crust is up to you.  If you have a favorite recipe for homemade pie crust, go ahead and use it. Be sure you use a recipe that makes 2 crusts, one for the top and one for the bottom.

If you don’t have a pie crust recipe or if you’d like an easy short cut, there’s no shame in buying prepared pie crusts from the refrigerated section.  That’s what we typically do.

If you have only one pie crust in your freezer or refrigerator, try our Classic Rhubarb Pie with one crust.

Recipe FAQs

• This can be a fresh rhubarb pie or a frozen rhubarb pie. We make it both ways.
• The filling may be pink or green just depending on the variety of rhubarb you use.
• You’ll need two pie crusts. Either buy some pre-made from the refrigerated section, or make your own. If you use a refrigerated crust, follow the directions on the package. Most say to remove from the refrigerator prior to using.
• This recipe calls for two heaping cups of rhubarb. Be sure this is only the stalks. Wash the stalks to remove the dirt. Cut into small chunks, approximately 3/4 inch.  If there’s woody ends, you can peel them off.
• Many people have asked if 2 cups of rhubarb is correct and it is! Our grandma was a frugal woman so she made her rhubarb stretch! It is also a sweet rhubarb pie because that’s how our dad liked it and our grandma always tried to make people happy!
• If you use frozen rhubarb, be sure to let it thaw and drain before using. We like to put our in a colander over a bowl while defrosting.
• The recipe follows a two-step cooking process. The first 15 minutes is at 425 degrees F, then turn down the oven and cook at 350 degrees F for an additional 45 minutes.
• The filling may seep out the top. This is ok! It tastes great anyways. You may want to place the pie pan on a rimmed baking sheet in case the filling bubbles over.
• To prevent the crust from getting too brown, you might need to gently cover the edges with foil part of the way through cooking.
• It is best if you allow the pie to rest for an hour before cutting. This lets the filling cool and set up. If you don’t do this, the filling will ooze out when you cut it.
• Check out our Amazon Store for our favorite kitchen essentials.
• Like the flavor of a strawberry rhubarb pie? Check out our Rhubarb Pie with Strawberry Jell-O.

How to keep rhubarb pie from being runny?

Our grandma taught us to both egg and flour as thickeners in rhubarb pie.  Mix the egg with vanilla.  In a separate bowl, combine diced rhubarb, flour and sugar; then combine the two mixtures.

Another tip to prevent runny rhubarb pie filling is to let it cool before serving so the sauce thickens.

​What makes rhubarb taste sweet in a rhubarb pie?

One word…sugar. Lots and lots of sugar. Rhubarb pie recipes call for a large amount of sugar to sweeten the tart rhubarb. If there’s not enough sugar, you’ll know once you bite into the pie because it will be tart.

Our Favorite Recipes from Grandma

Grandma has many more of our favorite recipes including Grandma’s Fantasy Fudge, Grandma’s Caramel Corn, Grandma’s Cherry Fluff, Grandma’s Butterscotch Rolls, and Grandma’s Cooked Ice Cream.

Rhubarb Recipes

• Rhubarb Nut Bread – An Amish Rhubarb Bread Recipe
• Rhubarb Dream Cake – A Moist Rhubarb Cake Recipe
• The Best Rhubarb Cobbler Recipe With Detailed Instructions
• Rhubarb Spoon Cake – A Step By Step Guide To Rhubarb Cake with Cake Mix
• Rhubarb Batter Cake