Published January 1, 2010. From Cook's Illustrated.
Our Foolproof Pie Crust recipe uses equal parts water and 80 proof vodka, yielding dough that is easy to roll out and bakes up flaky and tender. The key is the alcohol.
Eighty proof vodka is 60 percent water and 40 percent alcohol. Unlike water, alcohol does not contribute to the formation of gluten, the network of proteins that can cause a crust to turn leathery. Because the alcohol burns off quickly in the oven, drying out the crust, we could add enough vodka to keep the dough wet and extremely supple. But what if you don’t have a bottle of vodka in your pantry—can another 80 proof liquor be used in its place? We baked pie crusts made with rum, whiskey, and gin and compared them side by side with our vodka crust. Surprisingly, the vast majority of our tasters could not distinguish among the different flavors of booze; all of the crusts had a clean taste and flaky texture. So if vodka is not your tipple of choice, go ahead and substitute any 80 proof spirit.