By Orlando Ramirez
Sometime about mid-November, many people who never bake a pie any other time of the year are suddenly captivated by the idea of making a few from scratch for Thanksgiving.
At some point they find their brow smeared with flour and their hands sticky, the sudden realization that pie crusts can be a not-so-sweet science. It's time to call Shirley O. Corriher, author of "Cookwise" (Morrow), who understands pie crusts not just as a baker but also on the molecular level.
She has been a research chemist at Vanderbilt University, as well as giving cooking demonstrations for more than 25 years. Her expertise is such that other cookbook authors call her when they have a problem with a recipe they can't solve.
"The techniques and ingredients needed for tenderness are completely different from those needed for flakiness," she says "The goal for flakiness is to achieve firm, cold flat pieces of fat coated with flour," she says. "The goal for tenderness is to coat or grease flour proteins so they don't join together with water to form tough gluten."
The two essential ingredients in this marriage of proteins are flour and fat.
Corriher recommends a low-protein flour because it lessens the amount of gluten proteins. When water is stirred into flour it forms two proteins, glutenin and gliadin, which connect and cross-connect and become elastic sheets that trap air bubbles while baking, she explains. It creates that wonderful chewiness you want with bread but is the enemy of pie crusts.
To get a flaky and tender crust, try to find the flour with the lowest protein content.
"You used to be able to tell about flour before all the regulations," says Corriher. "The only flour I know that is low protein is cake flour, but it has a distinctive taste, slightly acidic."
Her solution is to mix 1 cup bleached, all-purpose flour with 1 cup Gold Medal Wondra or Pillsbury Shake Blend flour.
"These are really low-protein flours mixed with barley flour that has been presteamed so the starch is swollen," Corriher says, "It has a lot better taste than cake flour."
In a pie crust, fats are what create flakiness, and fats -- butter, margarine, shortening, lard and oil -- each have different characteristics, says Corriher.
Heat is also a factor in that fats melt at different temperatures, with butter being the firmest and oil being the most soluble. The more soluble fats grease the flour proteins and create a more tender crust.
In her recipe, Corriher mixes butter with lard or shortening to get the desired tender flakiness.
"Shortening is 100 percent fat and butter is 80 percent," she says. "They stay the same texture over the same temperature. Shortening makes it a breeze to roll out, and it holds its shape in the oven.