Blueberry Rhubarb Pie

Spring is all about berries. You can find many varieties of gorgeous berries from all over the place. Blueberries - among all the berries - are known as one of the antioxidant super fruits! It is delicious and also good for your brain and immune system. Although we don't associate dessert with "healthy" food, let's try to make it a bit healthier with 24oz of blueberries. :)

Blueberries are neither as sweet as strawberry or raspberry NOR as sour/tart as cranberries, so we need to add some other ingredients to give it more sweet and sour flavor. For sweet, we use sugar, and for sour-tartness we use rhubarb. The tart rhubarb has very interesting fragrant which reminds you of apple and strawberry, and the flavor goes very well with any berry.

Blueberry Rhubarb Pie
(Yield: one 10" pie / Cooking time: 2 hours*)
* The cooking time doesn't include one day of marinating time for blueberries with sugar.

Ingredients:
Pie filling
+ 150g diced fresh rhubarb
+ 6oz fresh blueberries (=170g)
+ 18oz fresh blueberries marinated with 1 cup of sugar for a day*
+ 2 tsps corn starch
+ (optional) 1 Tbsp lemon juice


* Mix 18oz blueberries and 1cup of sugar and leave it in a room temperature area for one day (covered with a lid or plastic wrap). The sugar will macerate blueberries and let the berries release juice. The following picture shows you the blueberries marinated for one day. If the blueberries are not macerated after one day, smash the berries with a fork lightly and let them sit in a room temperature area for another 6-12 hours until the berries have released enough juice.


Pie crust (Pâte sucrée)
+ 200g unsalted butter, icy cold and cubed
+ 400g unbleached all-purpose flour
+ 60g sugar
+ 2 eggs
+ 4 tsps icy water
+ 1/8 tsp salt

Procedures:
1. Drain the juice from macerated blueberries.


2. Pour the juice from #1 into a small pot and reduce to syrup consistency (almost like honey). Turn off the heat.


3. Pour all the blueberries (macerated ones and fresh ones) and chopped rhubarb to the pot and mix well. Let them sit for about 10-15 minutes. If more juice comes out and the mixture has too much liquid, strain the mixture and reduce the liquid again to syrup consistency, then mix with blueberries and rhubarb.


4. Sprinkle 2 tsps of corn starch and 1 Tbsp lemon juice to the mixture and mix well. Let the mixture cool completely to room temperature.


5. While the mixture is cooling, make pie crust. First, butter a pie pan and dust flour. Tap the pie pan to remove any excess flour. The inside of a pan should be thinly coated with butter and flour. Refrigerate the coated pie pan until the dough is ready.

6. Sift flour + salt + sugar, and cut icy butter into 0.5" cube. Not to make a flour mess in your kitchen, I recommend making the dough over a large parchment paper or in a large bowl.


! TIP ! If you have food processor, you can just add the sifted flour mix and cubed butters to the food processor and give them a quick whirl. Then, add eggs + icy water and pulse the button a few times to make the dough. The following steps are more traditional way to form the dough with your hands getting dirty!

7-1. The keys to make a good pie crust are (1) not to overwork the dough* and (2) work fast and over cold surface not to melt the butter**. So, when you mix the butter into the flour, please do not use your hands at first, but mix it roughly with your pastry scraper.
7-2. When the butter is roughly incorporated with the flour, use your fingers to smash the butter pieces into small pieces quickly.
7-3. When the butter pieces are about the size of lentil, make a well.
7-4. Pour one beaten eggs + icy water in the center of the well.


* The more you work the dough, more gluten is formed, and the gluten will result in hard chewy texture while pie shell should be flaky and crusty.

** The reason for using cold butter and being careful not to melt the butter: If you mix cold butter with flour, the butter doesn't melt into the flour - instead it forms very small butter pieces coated with flour. Those small pieces of butter melt away in baking and leave layers, which gives the flakiness to your pie shell. However, if you use warm butter, those "layers" are not going to form properly resulting in hard pie shell.

8. Combine the eggs+icy water and flour+butter. First, with your finger, incorporate the flour+butter mixtures into the eggs+icy water, then work the dough until it is homogeneous. Again! Be careful not to over work the dough. Add a few drops of ice water if the dough is too dry.

9. After mixing the dough, wrap it with a plastic wrap and place it in a freezer for 20-30 minutes. (Ideally, you need to rest the dough in a fridge for 2 hours.)


10. Preheat the oven to 400°F. Take out the pie dough from freezer, and roll 2/3 of the dough into a round shape, 1/8" (~3mm) thick. If you roll over a plastic wrap, it is much easier to flip the dough to pie pan.


11. Take out pie pan from the refrigerator and flip the rolled dough over a chilled pie pan. Trim the edges and poke the dough lightly with a fork. Place the pie pan in a freezer for 10 minutes.


12. While the pie crust is chilling, roll rest of the dough into rectangular shape, 1/8" (~3mm) thick and 10" length. Cut the dough into 1/2" wide strips using a knife or pizza cutter.


13. Take out the chilled pie crust, and pour the blueberry-rhubarb mixture evenly over the pie crust.


14. Arrange the strips from #12 on the pie.


15. Trim the edges again and place the pie pan on a baking pan. Blueberry-rhubarb mixture will bubble up while baking. To catch the possible spilt liquid from the pie, it is better to place the pie pan over a baking pan.


16. Bake the pie in a preheated oven (@400°F) for 15 minutes. Then turn down the oven temperature to 370°F and bake another 25 minutes. Turn the baking sheet so that the pie is evenly browned, and turn the oven temperature down to 350°F and bake another 20-25 minutes until the top of the pie is golden brown.

17. Take out the pie and brush the crust with diluted apricot preserve to make it shine.



Enjoy~