Why It Works
- Using all butter, instead of a combination of butter and shortening, gives this pie dough extra flavor.
- Combining the flour and butter in two distinct phases creates a dough that is tender and flaky yet extremely easy to roll out.
- Using a spatula to incorporate the water ensures flakiness.
If there's one thing that instills fear into the hearts and minds of American cooks, it's pie dough. I know. At one time, I was one of those people, and it was all because they were a mystery to me. What makes them flaky? What makes them tender? And most importantly, how come my pie dough used to bake up like a pliant piece of leather instead of a buttery and delicious crust?
What I'm after: The kind of crust that's substantial enough that it doesn't sog-out from a juicy filling but tender enough that it flakes in your mouth into buttery shards. A crust with substance, but not chew. A crust that divides along deep faults into many distinct layers separated by tiny air spaces and that cracks when bent. A crust that is never leathery or pliant, but not so tender or crisp that it crumbles instead of flakes. And of course, it should have a deep butteriness coupled with a balanced sweet and salty flavor.
Easier said that done, right? For many people, making pie dough is a crap shoot. Sometimes it bakes into a perfectly flaky crust, but other times it comes out tough. Sometimes you need just a couple tablespoons of water, sometimes a full 1/2 cup. What gives?
Turns out that the science of pie dough is really not all that complex, and once you get a grasp of what's really going on in between those flaky layers, baking it into a perfect crust becomes a matter of smarts, not luck.
The Myths Behind Flaky Pie Crust
On paper, classic pie dough is a mind-bogglingly simple recipe. Combine flour with a bit of salt and sugar, cut in some butter, lard, and/or shortening, then add just enough cold water to get it to come together into a disk. Roll it out and bake. That's it.
The underlying difficulty in the technique comes during the first stage of cutting the butter into the flour. Unless you make pie dough day in and day out, it's close to impossible to accurately cut butter into flour to the same degree on a consistent basis. Don't cut it in quite enough, and you need to add extra water to absorb the excess dry flour, resulting in the over-formation of gluten, and a tough, leathery crust. On the other hand, cut it in just bit too much, and you end up with way too little dry flour. Rather than having well-structured flaky layers, you end up with a crust that crumbles into sandy pieces, like this:
That is the reason why you sometimes need to add a couple tablespoons of water and other times up to twice as much to get the dough to come together—it's got nothing to do with the relative humidity of the air, as many books will have you believe. Indeed, in the short time that it takes to make a pie crust, flour will absorb approximately 0.1% of its weight in water, even in the most humid of environments. That's a small enough amount to effectively be zero.
So how does the simple action of cutting butter into flour result in layers and layers of flaky pastry? It's all got to do with the balanced interaction of gluten and fat.
Old school pastry books will tell you that when you cut butter or some other solid fat (like shortening or lard) into flour, what's happening is that you are encasing pockets of flour inside a shell of fat. Add water, and the flour is moistened, whereupon gluten—the network of proteins that lend structure to baked goods—is formed. When you subsequently roll this dough out, these pockets of fat stretch and stretch, eventually forming sheets of fat that separate sheets of gluten-enforced flour. Then, as the pastry bakes, the fatty layers melt, allowing the floury layers to separate from each other, solidify, and form the layers you see in a great pie crust:
It sort of makes sense; unfortunately, it's not a particularly accurate picture of what's going on. For starters, how could the action of cutting a solid fat into a relatively fluid mass of flour possibly cause it to coat pockets of flour in distinct bubbles? And even more importantly, if the fat is really coating these pockets of dry flour, then how would they get moist when you add water to the mix? Wouldn't the fat prevent any water from reaching the flour?
How Pie Crust Really Works
A few years ago, I developed a pie dough recipe while working at Cook's Illustrated. The one trick that got majorly hyped up about it was the inclusion of vodka in place of some of the water in the recipe. It was a pretty neat trick, if I do say so myself, and it solved one of the major problems people have with making pie dough.
But there's a good chunk of that article that seemed to have gotten glossed over by pretty much everyone, and I believe that it's a far cooler part than the headline-friendly vodka trick, and it has to do with the basic structure of dough.
You see, it turns out that when it comes to pie dough, our existing model has it wrong. In fact, it's not the fat that's coating pockets of dry flour. It's the reverse. It's the flour that's coating pockets of pure fat. With this model, things make much more sense. You can easily and intuitively see how fat gets coated with flour (think about dropping a pat of butter into a pile of flour, but on a much smaller scale), and with this model, when you add water, you are indeed moistening dry flour so that it can form sheets of gluten.
But there's a third element at play here that is often ignored: the flour-fat paste that forms at the interface between the pure fat and the dry flour. With this paste, what you're getting is essentially single particles of flour that are completely coated in fat. Since they can't absorb any water, they end up behaving in much the same way as pure fat.
To summarize, here's what we've got as we're forming a pie dough:
- Dry flour, completely uncoated by fat, that absorbs water when you add it, forming gluten that then gets stretched out into wide layers.
- Pure pockets of fat that will flatten out into long, wide, thin sheets as you roll out your dough, separating the layers of gluten-enforced flour from each other so that rather than forming a solid, leathery mass, they separate and gently puff as they bake.
- A flour-fat paste that functions much in the same way as pure fat does. As it bakes, the fat melts and a tiny amount of individually separated flour bits will deposit themselves and become incorporated into the gluten-enforced layers.
And if this flour-fat paste functions similarly to pure fat, doesn't that imply that we can completely replace the pure fat with this paste? Indeed, we can.
This beautiful, flaky pie crust was made with an over-processed dough like you see in the image directly preceding this one. But in order to get this crust, I had to take one additional step: add some more all-purpose flour to the flour-fat paste I'd formed, pulse it a couple times in the food processor just to distribute it evenly, then proceed just like a normal pie dough. I added water, chilled it, rolled it, and baked it.
The Benefits of The Food Processor Method
So that's all very interesting, but the real question is: Why should you care? How does this make forming pie dough any easier?
It does so in two ways. First off, this method completely removes the variability of a traditional pie dough recipe. By weighing out a given amount of flour and fat, combining them together until they form a near homogeneous paste, and then adding the remaining dry flour to that paste, you are very strictly defining exactly how much flour is used for gluten formation and how much ends up coated with fat. No more trying to visually judge whether the fat is properly cut into the flour. No more adding ice water a drop at a time until a dough is formed. The dough comes out the same, every single time.
The other key advantage is that your dough becomes much more pliable. The flour-fat paste formed at the beginning is much softer and more malleable than pure butter, which means that your final dough rolls out smoothly and easily with little-to-no risk of cracking like a traditional pie crust, even without the vodka.
On Butter, Shortening, and Lard in Pie Dough
The question of which fat makes the best pie crust is prime stomping grounds for eternal debate between bakers, and it comes down to a battle between texture and flavor.
- Pros: Excellent flavor. Forms distinct, large, flaky layers once baked.
- Cons: Difficult to work with. Butter melts at a relatively low temperature (below body temperature) and has a very narrow workable range. It's also got a relatively high water content (around 15–17%), which can cause excess gluten to form and turn your crust leathery if you aren't careful.
- Pros: Very easy to work with. Produces crusts that are extremely tender once baked.
- Cons: It has very little flavor of its own. (This could be a pro, if you want a neutral-flavored crust.) It's also soft over a wide range of temperatures, greatly increasing your chance of overworking your dough and turning the resulting crust crumbly instead of flaky.
- Pros: The best for working with—it has a wide workable temperature range and is not nearly as soft as shortening. Creates very tender, flaky crusts once baked.
- Cons: Unless you slaughter your own pigs and render your own leaf lard, or you have access to a good butcher, it's extremely hard to find high-quality lard. The stuff sold in supermarkets has a very savory, porky aroma, which makes for very porky-tasting crusts. Unless you're making savory pie, that's not generally desirable.
Because of these various characteristics, many recipes call for some combination of butter and shortening. In that case, shortening is so much softer than butter at room temperature, it's much more likely to form the fat/flour paste while the butter remains in discrete chunks. However, when using the method I've outlined above, you can cut the amount of shortening down to nothing, if you'd like. Depending on how tender you want your crust to be, anywhere below a 4:1 ratio of butter to shortening will work. To be honest, most of the time I'll make all-butter crusts, simply because shortening is just not something I keep lying around the house.
Tips For A Perfect Pie Crust
Finally, let me offer you a few tips to make the most out of your crust, no matter what recipe you decide to use.
Weigh Your Flour
Get yourself a scale. Honestly. Do it. You will not regret it. Measuring dry ingredients—anything more than a few teaspoons—by volume is simply not accurate. Depending on how tightly packed it is, the weight of a cup of all-purpose flour can vary by as much as 50 percent. 50 percent!!! No such problems with a scale. Five ounces of flour (the equivalent of one cup) is five ounces of flour, no matter how tightly it is packed.
Use a Food Processor
If there's one reason to own a food processor, it's to make pie dough. Nothing is as efficient or as consistent at cutting fat into flour. A stand mixer will do the job reasonably well; a pastry cutter will, too, though it requires much more work. You can even get a great dough using just your fingers. But, for the sake of pure ease, if you've got the processor, use it.
Keep Your Dough Cold
Just like with grinding meat, the key to great pie dough is to make sure that your fat doesn't melt too much. If your home is hot, make sure that you chill your dough as you work with it. In the summer with my oven on, the apartment pushes 80°F (27°C). Under these conditions, I'll put my dough back in the fridge three times: for 10 minutes immediately after incorporating the fat, for at least 2 hours after forming the dough into a disk and wrapping it, and for another 10 minutes after draping it in the pie plate before trimming and fluting the edges.
Use a Spatula to Incorporate Water
Your processed flour and butter are sitting there in the bowl of your food processor and you're tempted to save yourself a bit of cleanup by just adding the water directly in there, right? Don't do it! Sure, it'll work out okay, but you won't form nearly the same level of flakiness as you do if you incorporate with a spatula. Here's what a crust made 100% in the food processor looks like:
Compare that to the crust I made with the spatula:
See the difference? By using the spatula to fold the water into the dough, you're even more likely to end up with flaky layers.
Use a Tapered Rolling Pin
While a ball-bearing-based heavy-duty cylindrical rolling pin might fit in a Norman Rockwell painting, the slender, slightly tapered French-style rolling pin offers far more control when rolling dough, is easier to clean and store, and is usually cheaper.
And that's basically all I know about pie crust.
For a more traditional dough that's extra flaky but a little less beginner-friendly, check out our old-fashioned flaky pie dough.
2 1/2 cups (12.5 ounces; 350g) all-purpose flour, divided
2 tablespoons (25g) sugar
1 teaspoon (5g) kosher salt; for table salt use same weight or half as much by volume
2 1/2 sticks (10 ounces; 280g) unsalted butter, cut into 1/4-inch pats (see note)
6 tablespoons (3 ounces; 85ml) cold water
Combine two thirds of flour with sugar and salt in the bowl of a food processor. Pulse twice to incorporate. Spread butter pats evenly over surface. Pulse until no dry flour remains and dough just begins to collect in clumps, about 25 short pulses. Use a rubber spatula to spread the dough evenly around the bowl of the food processor. Sprinkle with remaining flour and pulse until dough is just barely broken up, about 5 short pulses. Transfer dough to a large bowl.
Sprinkle with water. Then, using a rubber spatula, fold and press dough until it comes together into a ball. Divide ball in half. Form each half into a 4-inch disk. Wrap tightly in plastic and refrigerate for at least 2 hours before rolling and baking.
When ready to shape the dough, pull out one ball, set it on a well-floured work surface, and sprinkle with more flour. Use a tapered rolling pin to start rolling the dough out into a circle, lifting the dough and rotating it while rolling to achieve an even shape. Continue rolling, changing the angle of your rolling pin as you go to get an even shape and thickness. The finished dough should overhang your pie plate by an inch or two.
Pick up the dough by carefully rolling it around your rolling pin, using your bench scraper to help lift it off the work surface. Unroll it over a pie plate. Gently lift and fit the dough into the pie plate, getting down into the corners.
For a single-crusted pie, use a pair of scissors to trim the dough so that it overhangs the edge by 1/2 inch all around. For a double-crusted pie, at this stage, fill it and drape your second round of pie dough over the top. Trim it to a 1/2-inch overhang along with the lower crust. Either way, tuck the overhanging edge(s) under itself all the way around the pie.
Flute the edges of the pie crust using the forefinger of one hand and the thumb and forefinger of the other. The single-crust pie shell is ready to be blind-baked or filled. For a double-crusted pie, brush with an egg white, sprinkle with sugar, and cut vent holes in the top with a sharp knife before baking.
For a slightly more tender crust, replace up to 6 tablespoons of butter with vegetable shortening. Pie dough can be frozen for up to 3 months. Thaw in refrigerator before rolling and baking.