Technique: Making Pie Dough
The perfect pie dough is characteristically an oxymoron - flaky, crispy, layers compress under your tooth and melt into a tender, buttery bite.
So how can pie dough be flaky and tender at the same time? Through a pretty neat series of chemical reactions that occur during the mixing process, and steam produced during the baking process. It sounds fancy and complicated, but it’s really as easy as, well, pie.
There are three important rules to remember when making pie dough:
1. Keep it cold.
2. Keep it short.
3. Keep it chunky.
Keep it cold:
Traditional pie dough (pate brisee) contains four simple ingredients: flour, butter, salt and water, with American versions incorporating varying amounts of sugar. Fats include butter, lard or vegetable shortening, used exclusively or in combination with each other. Regardless of the fats used in any recipe, the fat must remain cold at all times. To give the fat a fighting chance in your warm kitchen, place the fat in the freezer for a minimum of 30 minutes before using, chill the remaining ingredients in the freezer for at least 10 minutes before mixing, and use ice water instead of room temperature water. Cold fat will produce a flaky crust by creating small pockets of air between the layers of flour as it melts in the oven.
Keep it short:
Pie dough is known as a “short crust” dough, getting its name from the short strands of gluten that make up the texture. Short strands of gluten contribute to a flaky texture; long strands of gluten, found in bread, produce a chewy texture. Your main goal when mixing pie dough is to keep the gluten from developing into long strands. Fat interrupts the form of gluten, which is why shortening is called shortening — it “shortens” the gluten strands. And then there is a secret weapon in the fight against gluten development: acid.
Acid, in the form of vinegar, lemon juice, or even vodka, is like an added insurance policy for perfectly flaky pie dough, assisting the fat in stopping the form of gluten. Vinegar and lemon juice will impart their own flavor profiles into the dough, so no more than a tablespoon for a double crust recipe is recommended, with half that amount for a single crust recipe.
Keep it chunky:
In addition to keeping the ingredients and fat cold, the fat should be chunky, in varying sizes. Most recipes will instruct you to cut the fat into the flour until the mixture resembles coarse meal, with pea sized pieces of fat. By the time you reach a coarse meal consistency, you’ve overworked your dough, and most of the pieces of fat will be too small to create the noticeable flakes we crave in a pie dough.
Instead, cut the cold fat into 1/2″ cubes and then add all at once to your dry ingredients. Break up the fat with a pastry blender (by hand), until it just barely begins to crumble. Now it’s time to add your ice water. If making a double crust (see recipe below), begin with 1/4 cup of ice water; if making a single crust, begin with two tablespoons of ice water. Continue to crush the mixture with your pastry blender, incorporating the water one tablespoon at a time, until the dough begins to come together. Most of the chunks of fat should be no larger than a nickle, and no smaller than a dime — variety is key. It’s OK if some of the fat is smaller than a dime, as long as the majority of pieces are much larger. After about six tablespoons of water have been added, test your dough by holding a piece in your hand and gently squeezing it. If it holds together, it’s ready to be gathered and wrapped to rest in the refrigerator. If it crumbles, continue to add more water, one tablespoon at a time, until it barely holds together.
A few other tricks:
Knowing when to stop mixing can be tricky. Using a wide, shallow bowl and cutting the fat into the flour by hand is a great way for beginner bakers to assess how much water has been absorbed into the dough. Using a tall bowl will distribute the water unevenly, leaving many dry crumbs in the bottom of the bowl. A food processor can be used, but not recommended for beginners as it leaves little control over how the chunks of fat are cut or how moisture is distributed. Allowing the dough to rest overnight will produce a better finished product, by allowing the water to fully hydrate the flour. An overnight rest not only aids in the flaky, tender texture, but also prevents the dough from shrinking in the oven.