ANU VC observes international day for π with a pie
March 14 (written as 3/14 in some countries) is the international day of pi.
Pi is a mathematical constant that represents the ratio of a circle’s circumference to its diameter and appears in many formulas across mathematics and physics. Its decimal representation never ends or repeats permanently.
Pi day is a day to celebrate mathematics, take a crack at memorising the infinite digits of pi (3.14159), or to simply enjoy a slice of pie.
To mark the day Vice-Chancellor Brian Schmidt baked a homemade raspberry pie with berries from his garden.
Vice-Chancellor Professor Brian Schmidt’s raspberry pie recipe
INGREDIENTS
600 g raspberries
2/3 of a cup white sugar
4 tablespoons of cornstarch
1/2 teaspoon cinnamon
Juice of one small lemon
A two-layer pie crust
DIRECTIONS
Preheat oven to 210°C.
Roll out bottom layer of piecrust and put into tin. Store in Fridge.
Mix together, sugar, corn flour, and cinnamon until fully combined.
Add lemon juice to raspberries, and then pour over sugar mixture. Give the bowl of shake to try to evenly coat the berries with the sugar mixture.
Pour berries into pie shell.
Roll out top of the pie shell, and place over the top of the berries.
Crimp the edge, make sure to add some air slits in the crust top, and add whatever design you want. Optionally, brush a little milk across the crust for it to brown nicely.
Place pie on a circular cookie (pizza) sheet to catch any boil overs. Cook for 40 minutes. Cover the outside of the pie with aluminum foil after 30 minutes to keep it from browning too much.
Butter pie crust
INGREDIENTS
200 g unsalted butter, cold, cut into ~1.5cm cubes
320 g plain flour
1/4 teaspoon salt
1/4 teaspoon baking powder
90 g cold water (approx)
1 tablespoon vinegar
DIRECTIONS
Put flour, salt, baking powder and butter into a food processor and pulse until butter is pea sized.
Add vinegar, and approximately 75 g of water and pulse until the liquid is entirely mixed through. Check to see if the dough when pinched comes together to form pastry. If too dry, add small amounts of water, do a pulse or two, until the right texture is created.
Wrap pastry in plastic wrap and refrigerate for approximately 20 minutes before rolling out. Makes a two-layer piecrust.
NOTES
Avoid a super high protein flour for this like you might use for your sourdough. Normal Australian flour is appropriate.
Substitute a high-quality margarine for the butter to make this vegan.
Avoid over processing and over watering the pastry, you want little hunks of butter to remain in it, intact, and the pastry to just be able to come together.
If you want to freeze, roll out a crust worth, that’s half this recipe, to about 20 cm. Put between wax paper, and then in a plastic sealable bag, it can be stored for about a year. Defrost in the fridge overnight when you’re ready to use it.