Before I became a mother to my now 2 year and almost 5 month old daughter Anna I was a professor of mathematics at the Community College of Rhode Island. I loved teaching and studying math and hope to return to my profession one day soon. Until then I’ve been occupying myself with Anna, all things domestic and of course my blog! So in honor of Pi Day I give you this lovely Strawberry rhubarb pie, which I’ve made many times before, as this happens to be one of my all time favorite pies.
Pi, when rounded is roughly 3.14 and is the ratio of any* circle’s circumference to its diameter. This is always the same no matter how large or small the circle is! Pi also happens to be an irrational number, meaning that it cannot be expressed as the ratio of two integers. In other words, an irrational number is a number that has a decimal expansion that goes on forever with no repeating block pattern. Since pi’s decimal expansion is infinite, this means that even today we do not know, and nor will we ever know, the complete number for pi. Computers currently crank out more and more of pi’s decimal expansion each day always coming up with more and more of pi. That’s a lot of numbers in something as humble as a simple pie. Click here to see the first 10,000 digits of pi.
*Any Euclidean Circle
A Strawberry Rhubarb Pie for Pi Day
For the Crust
2 cups all purpose flour (plus a little extra for rolling)
1 1/2 sticks of cold butter
1/3 cup very cold water
A little milk for brushing on top
You need to start with very cold butter and very cold water. This is important!
In a large bowl cut the butter into the flour with a pastry cutter or with 2 knives until the butter is pea-sized. If you don’t have ice water then put a small glass of water in the freezer for about 5-10 minutes before you start. Now add the water one tablespoon at a time and work it in gently until the dough forms a ball that is not to crumbly and not too sticky. Don’t add the water all at once because you may not need it all! If the dough is a little wet add a little more flour but don’t overwork the dough. Be very gentle with it and try to handle it as little as possible. You don’t want to knead it, you just want to gently press it into a ball and then wrap it in foil and put it in the fridge. Let the dough rest for at least an hour and up to one day.
For the Filling
6 stalks of Rhubarb
500 grams or 1 pound strawberries
1 cup Sugar
4-5 tablespoons Corn Starch, Tapioca Starch or Flour
1 Egg lightly beaten
1 Tablespoon of finely grated Lemon zest *optional
Preheat oven to 350° F. Chop rhubarb into small/ 1 inch pieces and cut strawberries in half or in quarters. Combine in a bowl with sugar, starch and zest. Then stir the egg into the fruit mixture. Roll out half of the pie dough and place in the pie plate, there should be a little overlapping the edge. Pour fruit mixture into the pie plate. Roll out the second half of the pie dough. Cut decorative holes or lines onto the center of the crust with a sharp knife. Place the crust on top of the pie and crimp the edges. Brush the top with milk and bake for 1 -1 1/2 hours or until the insides are bubbling and the crust is golden brown. Let sit for a few hours before cutting to let the filling set.