Move over, strawberries — there’s a new perfect pairing for rhubarb. Full of juicy blueberries, this Blueberry Rhubarb Pie is the perfect early summer fruit dessert.
You knew this was coming, right? Every spring, at least one rhubarb dessert makes an appearance on Bunsen Burner Bakery. (Spoiler alert: this year there will be two!)
For a weird vegetable that is definitely not a mainstay of the American diet, I sure do get a lot of “what can I do with all this rhubarb?!” questions.
If you’re part of a spring/early summer CSA, or frequently visit farmers’ markets, you’re guaranteed to come across some rhubarb. And I’m here to help you figure out how to use it all up.
Strawberry rhubarb pie is certainly the most popular option. (If you’re looking for an easier take, check out these strawberry rhubarb oatmeal bars.)
But today I’m going to suggest something that I’d argue is even better: a blueberry rhubarb pie.
Not only does it have a much more fun name (bluebarb pie!!), I find blueberries are just overall better in a pie.
No need to slice them. They hold up better without getting super mushy. And the combination of the red rhubarb and purple blueberries blend into a gorgeous magenta-colored filling.
Dare I suggest that this will become your favorite version of rhubarb pie? Because it definitely will.
I’ve shared my favorite pie crust recipe before, and all my best tips for the foundation of a perfect pie. For more detailed tips and tricks, I highly recommend reading through the post!
But for a brief rundown about how to make your best pie crust ever, here are a few pointers:
Not into making your own pie dough? No problem! Use a store-bought pie crust from the freezer section of the grocery store. You’ll want a regular size crust, not a deep dish crust.
For the filling, we’re going to use 3 cups of chopped rhubarb and 2 cups of blueberries. These can be either fresh or frozen — if frozen, thaw the berries first.
We’ll also add some sugar, lemon juice, and a pinch of salt.
Fruit such as blueberries contain a lot of water, so we also need something to absorb all that extra moisture.
There are several options here. Some people use flour, some use cornstarch, and others swear by a substance called ClearJel.
Different pies benefit from different times, and for this blueberry rhubarb pie, my favorite is…
Instant tapioca!
Tapioca is derived from cassava, a root vegetable. It’s sold as flour, starch, pearls, and beads. For this pie, we’re looking for instant tapioca (sometimes called minute tapioca), which is ground-down tapioca pearls.
Tapioca thickens beautifully, never feels gummy, and doesn’t leave the filling cloudy and opaque like flour and cornstarch.
Why is tapioca my favorite filling for this kind of double-crust pie? It’s time for my favorite subject… kitchen chemistry!
Kitchen Chemistry
Unlike flour and cornstarch, tapioca retains its moisture-absorbing properties even in the presence of an acid, unlike flour and cornstarch, both of which start to break down once exposed to acid and is better at holding its shape at room temperature.
Tapioca works better the more finely it is ground, so if your instant tapioca has large granules, I recommend giving it a spin in a food processor or blender before using it.
You’ll also want to let the filling rest for at least 10 minutes to allow the tapioca to soften and start to absorb the fruit juices.
To make sure it’s fully activated, bake the pie until it’s visibly bubbling in the oven, and let the pie sit out overnight before slicing – the tapioca needs time to re-bond after baking!
While it might sound a little corny, you can tell a pie is done using a combination of all your senses.
It should smell like pie. It should look brown. You should hear the pie filling bubbling, making a thumping noise. And you should be able to feel that the fruit is soft and cooked through.
The pie is done with the filling is bubbling up in the middle of the pie, not just the edges. Especially for juicy pies, make sure the bubbles are rolling slowly and thick, rather than quick, watery bubbles on the edges.
But what about a double-crust pie? It’s hard to see inside to see if the juices are bubbling!
If the vents on the pie have started to seal shut, use a knife to carefully cut them open again so you can see inside the pie and look for rolling bubbles.
To test the fruit, take a toothpick and insert it inside one of the vents. If it’s difficult to insert the toothpick through a piece of rhubarb, the filling is undercooked. You’re looking for a toothpick that slides in effortlessly with no resistance.
Move over, strawberries -- blueberries are the new perfect pairing for rhubarb. This Blueberry Rhubarb pie will be your new favorite!
Pie will keep at room temperature for 24 hours, refrigerated for up to 3 days, or frozen for up to 3 months. To freeze the whole pie, wrap the pie tightly in plastic wrap and place in a freezer bag. To freeze individual slices, place slices on a cookie sheet in the freezer. Once fully frozen, wrap each slice in plastic wrap, followed by a layer of aluminum foil. Defrost at room temperature before eating.
A Bunsen Burner Bakery Original Protocol
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