From America's Test Kitchen Season 9: The Best Blueberry Pie
Unless you’re a practiced pie baker, it’s hard to get the same results every time. We wanted a recipe for pie dough that rolls out easily every time and produces a tender, flaky crust.
The first step was to determine the right fat. As with our basic dough, a combination of butter and shortening provided the best balance of flavor and tenderness. Once again, the best tool to cut the fat into the flour was the food processor. To ensure same-sized pieces of butter time after time, we eliminated the pieces entirely and made a paste instead. Rather than starting with all the flour in the processor, we put aside 1 cup of flour and processed the remaining 11/2 cups with all of the fat until it formed a unified paste. We added the reserved flour to the bowl and pulsed it until it was just evenly distributed. Finally, we tackled the tenderness issue, which is partially determined by the amount of water added. In order to roll easily, dough needs a generous amount of water, but more water makes crusts tough. We found the answer in the liquor cabinet: vodka. While gluten (the protein that makes crust tough) forms readily in water, it doesn’t form in ethanol, and vodka is 60 percent water and 40 percent ethanol. So adding 1/4 cup of vodka produced a moist, easy-to-roll dough that stayed tender. (The alcohol vaporizes in the oven, so you won’t taste it in the baked crust.)
For one 9-inch Double-Crust Pie
Vodka is essential to the texture of the crust and imparts no flavor—do not substitute. This dough will be moister and more supple than most standard pie doughs and will require more flour to roll out (1/4 cup must be used to prevent the dough from sticking to the counter).