Last week, my sister, Pat, drove to Pittsburgh from Maryland to celebrate her nephew's first Holy Communion. On the way, she stopped at a farm stand and bought two pies. One was rhubarb and strawberry, and the other was blueberry.
In the chaos of the day, I missed a chance to taste either one. Fortunately, there was a little bit of the blueberry pie left over, and I had a little piece last night. It was heavenly — tart and sweet, with earthy flavors of mace and cinnamon. It reminded me of all the slices of blueberry pie I've sampled at diners from Vermont to Philadelphia.
But what really distinguished this pie was its texture — firm but not rubbery and with distinct berries embedded in a thick berry puree. The filling had a soft sheen and did not dribble out onto the plate when the slice was served.
I always have problems with pie fillings because they never become as firm as those in commercially prepared pies. I've tried different kinds of thickeners, but they can be tricky. So here are some of the rules of the road for thickening pie fillings.
FLOUR
There are lots of bakers who will tell you that this is the only ingredient for thickening fillings. The rule of thumb is about 1/3 cup to each quart of fruit. Most recipes call for sprinkling it directly on the cut fruit before putting it in the crust. My concerns are that it sometimes gives the filling a pasty consistency and doesn't have the sheen of other thickeners.
CORNSTARCH
This is a good all-purpose thickener that gives a nice gloss, and it doesn't have that raw flour flavor. But cornstarch doesn't work when your filling is high in acidity (cherries) or if you plan to freeze the filling at any time.
ARROWROOT
This is the Cadillac of thickeners because it imparts no flavor of its own but provides a high gloss, and just 1 tablespoon will firm up each cup of liquid. It's fine for high- and low-acid fruit mixtures, but it creates a gloppy mess if mixed with any dairy product.
TAPIOCA STARCH
We're not talking about tapioca, either regular or instant. Both of those could be used as thickeners, but they leave behind either small or large gelatinous balls that can interfere with a pie's smooth texture.
Tapioca starch is a fine powder made from tapioca. It creates a perfectly smooth filling and imparts a high gloss for a tasty-looking result. It's the perfect product to use with high-acid fruits.
You can make up a thickening mixture by combining 1/2 cup flour with 1/4 cup cornstarch and 1/4 cup tapioca starch. This makes enough for four 9-inch fruit pies.
One thing I do know: If I keep sampling these pies, I'll keep getting thicker!
Blueberry Pie
- Pastry for 2-crust 9-inch pie
- 2 pints fresh blueberries
- 1 lemon, grated peel and juice
- 3/4 cup sugar
- 1/4 cup thickening mixture (see above)
- 1/4 teaspoon ground cinnamon
- 1/4 teaspoon ground mace
- Ice cream
Heat the oven to 400 degrees. Line the pie pan with 1 piece of the pastry.
In a large bowl, toss the berries with the lemon juice. Add the lemon peel. Add the sugar, thickening mix and spices and mix well, being careful not to break too many berries.
Turn into the pie crust and mound the filling slightly in the center. Cover with the second crust. Crimp the edge and cut several slits in the top for steam to escape.
Place the pie on a foil-covered cookie sheet to catch any spills. Bake for 10 minutes, then lower the temperature to 350 degrees and bake for another 35 to 40 minutes. The crust should be golden brown and the filling bubbly.
Allow to cool and serve with ice cream.
