Fat, flour, water, and salt. Everything I've been told leads me to believe that this is all I need for a perfect pie crust. I just don't know how much of each I need, or how I'm going to put it together. I went through about eight different pie crust recipes, and they all disagree, so I'm going to wing it and hope for the best.

Pie crust, unlike most baking, does not appear to be a matter of strict formulas. The fat-to-flour ratio in the recipes I looked at ranged from 2-to-3 to nearly 1-to-1 by weight. And pie really is a creature of the home kitchen, where the baker's scale gets less props than the coffee-can scoop. Fannie Farmer would not weigh flour for her pies.

I settle closer to the 1-to-1 end of the spectrum, using just over 3 cups of flour with a half-pound of lard and a stick of butter. I sift the flour with a healthy pinch of salt into a stainless steel bowl. I cut up the cold fats into rough chunks and toss them into the flour. I wash my hands in cold water to chill them, and set myself to working the flour into the fat. You're supposed to use your fingers as much as possible when mixing pie dough, because allowing the fat to rub up against the palms (which are warmer) can melt it, preventing you from creating the odd-sized lumps of fat that will eventually create the flaky layers in the pie crust.

Maybe I've never had a really good pie crust before, but I'm not so clear on the whole "flakiness" thing. My guess is that it works basically like puff pastry, which I think I understand. These doughs take advantage of two scientific principles: (1) oil and water don't mix; and (2) water expands as it is heats up and converts into steam. In puff pastry, a water-based dough is wrapped around a block of butter, and then folded into hundreds of alternating layers. As the puff is cooked, the water expands, but each layer of dough is prevented from breaking through to the next layer because there's oil (butter) in the way, and oil and water don't mix. The fat, held in place in its solid state by the structure of the dough, eventually melts and goes whither it will, and the steam rushes in to fill (and even stretch) the void left behind. In the process, the layers (which get lightly browned in the melting fat) get pushed apart by the pressure of the steam, and you end up with mille-feuille, a thousand layers of golden flaky pastry expanded to several times their original height.

Presumably, pie dough works on the same principles, only on a smaller scale. Flour particles are surrounded with blobs of fat. A little water is added to hold the mess together. As the crust is cooked and the water expands, the flour is kept from absorbing it by its protective layers of fat (with which the water cannot mix). As the blobs of fat melt away (browning the flour in the process), steam rushes in to fill the empty space left behind. The result is lots of little air pockets in the finished product. And when two pockets of steam press against opposite sides of a fat-shrouded bit of flour, the result is a thin layer of golden pastry surrounded by air - in other words, a flake.

Puff pastry is just fine by me, so I'm guessing a flaky pie dough will be plenty good too. I make sure to leave lots of blobs and streaks of fat interspersed throughout my dough. When the fat and flour are mixed in to my liking, the result looks like wet, clumpy white sand, streaked here and there with little swaths of yellow and white. I have a glass of ice water at the ready, which I drizzle in a few drops at a time, trying desperately not to shatter the delicate balance of textures I've worked so hard to achieve. When the dough feels like it's just starting to hold together, I toss it in a ziploc bag and stick it in the fridge. The flour will continue to absorb the water for a while, so it isn't necessary to have a solid mass of dough at this stage. After it rests for an hour, it'll be cohesive enough to roll out and fill with my stash of hand-picked apples.