A FEW THOUGHTS ON BLUEBERRY PIE

We are currently in the thick of blueberry season, encouraging bakers to carefully balance quart containers of freshly picked blues under their chin and embrace the heat of a 400 degree oven on a 90 degree day.
Blueberries are available in supermarkets year round, but they are at their sweet/tart best (in the Northeast),   in late summer. Better still, find a local grower who encourages pick-your-own or support your local  farmer's market. I approach most summer pies, (blueberry included), with a time frame that works backwards. The first thing I ask myself is, when am I planning to serve the pie? I also factor in time to par-bake the bottom crust before filling,  prepare the top crust in advance, (lattice or crumble?) and cooling time. It's also worth a few moments to choose a suitable pie plate. Less glitzy than deep-dish earthenware or ceramic, metal pie plates and humdrum aluminum pie plates are great pie vessels. They also move seamlessly from freezer to oven which is important; once assembled, juicy summer pies can benefit from a brief time 'chilling' in the freezer (or if you're tight on freezer space, the fridge) before going into a hot oven. It gives the pie, particularly the top crust, a chance to set up. I'm less likely to use glass pie plates for freezer-to-oven baking these days simply because depending on the age and composition of the glass pie plate, there's a small chance that a ding on the counter or wear and tear might impact its durability. (If you do prefer baking in a Pyrex or old-school glass pie plate, always place the 'refrigerator cold' (not 'freezer cold') pie plate on a room temperature baking sheet before baking. When you remove the pie from the oven, set the pie on a towel lined cooling rack to avoid thermal shock, Exploding pie plates are rather rare, but high oven heat and cool counter tops can cause unwanted pie plate drama. Nobody wants that.)

Blueberry pie can be made year round, but it seems to taste brighter and sunnier in the summer months. At other times of the year, a grocers' freezer can provide inspiration. Fresh blueberries out of season, though convenient tend to be mouth-puckering tart and not necessarily in a good way. Combined with frozen wild blueberries, the fresh/frozen hybrid will bake up into a flavorful filling with a little more textural interest.  Always taste the filling as you go along- what you don't want is a pie that is scary sweet.  

I prefer waiting for blues in season, aiming for 7 cups of blueberries per pie. This means starting with 3 and 1/2 pints of berries. Once rinsed, stemmed and picked through, half of the berries are combined with the sugar, spices, and thickener called for in the recipe. Cooking the fruit over medium/low heat, stirring gently to prevent scorching, eliminates some of the excess moisture and concentrates the flavor. Once the sweetened berries have thickened, remove them from the heat, add your preferred zest and juice, and optional extract. (Some bakers add the slightest hint of almond extract, others choose vanilla.) Small adjustments enhance the flavor of the filling without overpowering it, so go easy. You're looking to capture the flavor of blueberries, not spices, not extracts.
 
Add the remaining berries to the cooked filling and let the filling cool completely. When you are ready to assemble the pie, taste the filling and see if you’re happy with the spice/citrus level. If the filling tastes flat or lackluster, a tablespoon or two of good quality preserves can elevate the flavor. Ideally, you want to add wild blueberry jam, but in a pinch, you can add blackberry or black currant or even (desperate times) a berry blend. As the berries continue to bake in the oven, they will break down, thicken and concentrate in flavor. 
 
Set the par-baked/cooled bottom crust on a parchment lined baking sheet. Retrieve the top crust from the refrigerator. Brush the edge of the bottom crust with a thin coating of egg wash. Pour the cooled filling into the pie crust. You might want to reserve about 3-4 tablespoons of liquid if the filling is particularly juicy. (I find this helps curb a soupy filling and makes the pie a little more slice-able.) Add the top crust, carefully sealing the top to the bottom, fluting the edge with your fingers. Egg wash the top crust as well, (unless it's a crumble), sprinkle with coarse sanding sugar (if you have some) or a little Sugar in the Raw or even a light dusting of granulated sugar. 

Take the time to place the assembled pie in the freezer for 30 minutes to set the crust. If you are tight on freezer space, you can refrigerate instead. (It seems like overkill, but it’s not; this will prevent your top crust from slipping down over the edge or if you've opted for a crumb topping, it adds some protection from over browning.) While the pie is chilling, heat the oven to 400 degrees F.  Set the chilled pie on the parchment lined baking sheet and bake on the bottom rack of the oven for 20 minutes; this helps finish baking the bottom crust.  After 20 minutes, reduce the oven temperature to 375 degrees F, and move the pie to the middle rack. Continue baking for an additional 40 minutes, covering the edges of the pie with strips of aluminum foil if they are getting overly dark. Every oven is different, but the pie really needs a good hour plus in order to bake thoroughly. The pie should bubble around the edges and from the center before you remove it from the oven. If it’s not bubbling but looks perfectly golden, turn the heat down to 350 degrees F and give it another 8-10 minutes. Look for noticeable bubbling before you call it finished.
More Waiting Required 
Blueberry pie needs plenty of time to cool before slicing or you risk serving blueberry soup. Starting the pie early in the day gives you plenty of time for the pie to pull itself together. If not, it's best to serve it the following day. (Think breakfast.) The cooled-to-room temperature pie can sit on the counter overnight, covered with a clean kitchen towel, aluminum foil, or a cake dome. To avoid a soggy crust, make sure the pie has cooled before you cover it.
 
(Comb through the Recipe Index for pie crust inspiration)
For the bottom crust, One 9” pie crust, par-baked and cooled (pie plate should measure 9 inches by 1 and 1/2 inches deep)
For the top, One single recipe pie crust for lattice top or Cornmeal Crumble 

​For the filling-
7 cups of blueberries (3 and 1/2 pints fresh, rinsed/picked over for stems, OR 36 ounces of frozen should yield approx 7 cups, OR use a combination of fresh and frozen to yield 7 cups)
½ cup granulated sugar
¼ cup brown sugar
2 teaspoons lemon zest
½ teaspoon cinnamon
pinch of salt
3 tablespoons cornstarch or 4 tablespoons all-purpose flour (cornstarch yields a less runny filling)
1 tablespoon freshly squeezed lemon juice
1 tablespoon unsalted butter, cut into pieces
 
egg wash made with 1 egg and 1 teaspoon water
sanding sugar for sprinkling
 
If using fresh berries, after rinsing and removing stems, lay them out on a clean towel to dry. Whisk together the sugars, cinnamon, salt and cornstarch or flour. Place 3 and 1/2  cups of the berries in a heavy bottomed pan with the sugar/spice/cornstarch (or flour) mixture, stirring to mix. Cook over medium heat until the fruit thickens, about 6-8 minutes, stirring frequently to prevent scorching. Pour the cooked berries into a large bowl, add the lemon zest, juice and the remaining berries. Stir to combine and set aside to cool completely.
 
Prepare your top crust (I prefer to cut 1” strips for a lattice) and keep it chilled in the refrigerator. Place the par-baked bottom crust on a parchment lined baking sheet. Brush the top edge of the crust with a thin coating of egg wash. (Taste the filling- if it tastes a little flat, adjust with a little extra zest or some jam; don’t be tempted to over sweeten. I always reserve 3-4 tablespoons of the liquid in the berries and set it aside; it helps prevent some of the ‘soupiness’ of the filling; you can cook this down a little bit and pour it over yogurt or ice cream or alongside the pie.) Pour the cooled berry mixture into the pie shell and dot with butter. Place lattice strips on top of the filling; weaving them looks lovely but you can simply lay half of the strips horizontally and the other half vertically and they will bake up just fine.  Because the bottom crust has been par-baked it might be a little fragile. Carefully attach the top to the bottom, rolling the top crust under to form an edge; crimp the edge with your fingers or gently press together using a fork. Make sure the top and bottom crusts are sealed so the filling doesn’t sneak out of the sides. Brush the top crust with egg wash and sprinkle with sanding sugar. Place the pie in the freezer for 30 minutes before baking or fridge if you're tight on freezer space.. Preheat the oven to 400 degrees F. Place the pie on the parchment lined baking sheet. Bake the pie on the bottom rack of the oven at 400 degrees F for 20 minutes. Reduce the oven temperature to 375 degrees F and move the pie to the middle rack. Continue baking for an additional 40 minutes, covering the edges of the pie with strips of aluminum foil if they are getting overly dark. Every oven is different, but the pie really needs a good hour plus in order to bake thoroughly. (In my oven, 75 minutes is the ticket.) The pie should bubble around the edges and from the center before you remove it from the oven. If it’s not bubbling but looks perfectly golden, turn the heat down to 350 degrees F and give it another 8-10 minutes. If you have an insta-read thermometer, the internal temp should be 200 degrees or a little higher. Let the pie cool completely before slicing so the juices have time to thicken; at least 4 hours, preferably more. Any leftovers should be covered (a large inverted bowl works well) and can sit at room temperature for up to two days. Beyond that, cover with plastic wrap and refrigerate.