Easy Rhubarb Crumble Pie

Inside: How to harvest rhubarb, make a delicious rhubarb crumble pie, and preserve extra rhubarb in the freezer.

How to Harvest Rhubarb and Freeze It

First, you need fresh rhubarb. If you’re harvesting your own, gently pull the stems off instead of cutting them. This protects the plant and encourages healthy regrowth. Be sure not to harvest all the stems at once—leaving some behind helps the plant recover. This is also a great time to fertilize and water the plant generously to support continued growth.

If you end up with more rhubarb than you can use right away, don’t worry—rhubarb freezes beautifully. You can freeze the stalks whole or cut them into smaller pieces first. Pre-cutting them makes it easier to use just a small amount later, and also helps save space in the freezer. When you have more time, you can turn your frozen rhubarb into a delicious custard pie or refreshing rhubarb juices.

Easy Steps to Freeze Your Rhubarb

• Harvest gently by pulling the stems off the plant
• Cut off the leaves from the top—they are poisonous. Also, trim the lowest end of the stem
• Rinse the stalks under water
• Cut into smaller pieces
• Spread the pieces on a baking sheet and place them in the freezer
• Once frozen, transfer the pieces to a plastic bag

If you don’t have your own rhubarb plant, you can buy fresh rhubarb at the grocery store.

Simple Ingredients

Rhubarb Base for Rhubarb Pie

• Rhubarb – The star of the recipe!
• Potato starch (also called potato flour) – used as a thickener for a smooth, non-watery filling.
• Vanilla sugar – Adds extra sweetness to balance the tartness of the rhubarb.
• Cinnamon (optional) – I love how cinnamon adds depth; it pairs wonderfully with the topping.
• Cardamom (optional) – In my opinion, cinnamon and cardamom together give the best flavor for the crumb topping.

Topping Ingredients for a Lovely Rhubarb Crumble

• Oatmeal – I used rolled (old-fashioned) oats for a nice chewy texture. You can blend them in a food processor if you prefer a smoother consistency.
• Special wheat flour – A flour with higher protein content works best for structure.
• Butter – I use salted baking butter.
• Caster sugar – This recipe uses less sugar than typical rhubarb desserts. I’m not a big fan of white sugar and always try to use healthier alternatives.
• Sea salt – Just a pinch to enhance all the flavors.

How to Make Rhubarb Crumble Pie

Set the oven temperature to 200°C (about 390°F). Rinse the rhubarb stems and cut them into small pieces. The smaller the pieces, the more mushy the pie will be. In a large bowl, mix the rhubarb with potato flour, vanilla sugar, cinnamon, and cardamom. Place the rhubarb mixture in a greased ovenproof dish. Cut the cold butter into small pieces and combine it with oatmeal, flour, sugar, and salt using your hands. Massage the mixture until it forms a crumbly texture. If the topping feels too dry, add a little more butter. If it feels too sticky, add more oats. Spread the crumble topping evenly over the rhubarb. Bake for 25–30 minutes in the lower third of the oven, until the topping turns golden brown. Remove the pie from the oven and allow it to cool before serving. It’s perfect with vanilla sauce or a scoop of vanilla ice cream.

How to Store the Baked Pie

The pie can be stored in the refrigerator for about 3–5 days. For longer storage, let the pie cool to room temperature before placing it in the freezer. Alternatively, you can bake the pie in a metal pie plate, which is ideal for freezing. Allow it to cool completely before placing it in an airtight container and putting it in the freezer.

Measurement Notes

• 1 deciliter (dl) = about ⅖ cup (so 3 dl = 1¼ cups, 2 dl = ¾ cup + 1 Tbsp)
• 500 grams rhubarb = about 4 cups, chopped
• 150 grams butter = about ⅔ cup
• Vanilla sugar is used in European baking—substitute with 1 Tbsp sugar + ¼ tsp vanilla extract if needed.