PIE CRUSTS

Making good pie crust can be a simple procedure, but almost everyone who has tried can tell horror stories of crusts that turned out hard, soggy, flavorless, oversalted, underbaked, too crumbly, or unworkable. Advice is easy to come by: One expert says that butter is the secret to perfect crust; others swear by vegetable shortening, lard, or even canola oil. Some omit salt, some omit sugar, some insist that working the dough by hand is essential, some use cake flour in addition to all-purpose flour, some freeze the dough, some do away with the rolling pin. . .and so on.

INGREDIENTS

Simple as it can be, pie crust—essentially a combination of fat, flour, and water—raises numerous questions: What are the ideal proportions of the main ingredients? What else should be added for character?

FAT

The most controversial ingredient in pastry is fat. We've found that while all-butter crusts taste good, they are not as flaky and fine-textured as those made with some shortening, which are our favorites. All-shortening crusts have great texture but lack flavor, oil-based crusts are flat and entirely unappealing, and those made with lard are not only heavy and strongly flavored but out of favor due to health concerns. We've experimented with a variety of combinations and ultimately settled on a proportion of three parts butter to two parts shortening as optimal for both flavor and texture.

There's a reason shortening works: Vegetable shortenings such as Crisco are made from vegetable oil that has been hydrogenated to incorporate air and to raise its melting point above room temperature. (This is much the same process as "creaming" butter and sugar, in which the sharp sugar crystals cut into the fat to create pockets of air.) The absence of hydrogenation is the reason that regular vegetable oil, which holds no more air than water, makes for poor pie doughs, whereas Crisco, which is about 10 percent gas, does a good job of lightening and tenderizing.

We also experimented with the relative proportions of fat and flour and finally settled on a ratio of two parts flour to one part fat. This ratio results in a relatively high-fat crust (you will find other recipes containing four parts of flour to one part of fat). But we found that the two-to-one proportion produces crusts that are easy to work and, when baked, are more tender and flavorful than any other.

FLOUR

The protein content of flour is important in any sort of baking. Bread flour, which is high in protein, produces a strong, elastic dough. Low-protein pastry flour makes for a soft, tender crumb, the best for cakes. Pie crusts fall in between and thus are best made with all-purpose flour, a combination of bread and cake flours. No matter what we've tried—substituting cornstarch for part of the all-purpose flour (a cookie-baking trick that increases tenderness), adding a quarter teaspoon of baking powder to increase rise, or mixing cake flour with the all-purpose flour (again, to increase tenderness)—we've always come back to plain old all-purpose flour.

WATER

We experimented with a variety of liquid ingredients, such as buttermilk, milk, and cider vinegar, a common ingredient in many pastry recipes. None of these improved on our basic recipe, so we recommend that you stick with ice water.

SALT AND SUGAR

After testing amounts ranging from a quarter teaspoon to as much as two tablespoons, we settled on one teaspoon of salt and two tablespoons of sugar for a double-crust pie, amounts that enhance the flavor of the dough without shouting out their presence.

TECHNIQUE

You can make a pie dough by hand, but the food processor is faster and easier and does the best job of cutting the fat into the flour. First cut the butter in cubes. Then pulse the butter and flour together five times, add the shortening, and pulse four more times. Proper mixing is important: If you undermix, the crust will shrink when baked and become hard and crackly. If you overprocess, you'll get a crumbly, cookielike dough.

When you've combined the flour and fat, dump the dough into a bowl and add the ice water. Use a rubber spatula and a folding motion to mix in the water; this exposes all of the dough to moisture without overworking it, something that can happen if the dough is left in the food processor and the water is pulsed in. Using a spatula to incorporate water allows you to minimize the amount of water used (less water means a more tender dough) and reduces the likelihood of overworking the dough.

Once you have a ball of dough, divide it in half (if making a double-crust pie), flatten each piece into a disk, wrap each one in plastic wrap, and rest the dough in the refrigerator for 30 minutes. You can give the dough a longer rest period (an hour is best if the weather is warm), but then let it warm up slightly before attempting to roll it.

This dough is easy to roll if you follow a few basic guidelines. Flour the work surface very lightly; too much flour will be absorbed by the dough and cause it to toughen. If the dough seems too soft to roll, refrigerate it again rather than adding more flour.

EQUIPMENT

You need a tool to make the dough, something to roll it out with, and then a vessel for baking the pie. Here are our recommendations.

FOOD PROCESSOR

Our first choice for cutting fat into flour to make pie dough is a food processor. Look for a machine with an 11-cup capacity bowl; it should weigh at least 10 pounds, so it won't jump around on the counter. We recommend models made by Kitchen Aid and Cuisinart.

PASTRY BLENDER

Of course, bakers made pies long before the invention of the food processor. There are three low-tech options for cutting the fat into the flour: a pastry blender, a fork, and your fingertips.

If you don't have access to a food processor, we recommend the pastry blender, a D-shaped device consisting of a straight handle with a set of stiff wires bowed from one end to the other. A pastry blender will not cut the fat into the flour quite as easily as a food processor, but it is more efficient than a fork.

As for your fingertips, this method works for some experienced bakers, but many cooks find that the heat from their fingers melts the butter. In our tests, handmade pie crusts turned out less flaky and more brittle than those made in a food processor or with a pastry blender.

ROLLING PIN

There are three main types of rolling pins: one basic American style and two French styles.

American-style pins have a metal dowel running through the center, handles on either side, and are usually 10 to 15 inches long, not including handles. Their ball bearings and handles allow extra pressure to be exerted during rolling, which makes them best suited for heavy bread doughs.

French pins are usually 18 to 20 inches long and have no handles. This type of rolling pin is simply a round length of wood, like a dowel, which can be used on any type of dough. Some French pins are tapered, with the ends narrower than the middle. This is the type we recommend for pie making. The tapered ends make this kind of rolling pin lighter and more delicate, and therefore more precise. It's also easier to make a perfectly round crust by anchoring one end of the pin in the center of the dough with one hand and pivoting the pin with the other hand.

PIE PLATE

We tested the three main types of pie plate—glass, ceramic, and metal—and found that a Pyrex glass pie plate did the best job of browning the crust, both when filled and "baked blind," as explained on Prebaked Pie Shells. Several metal pie plates also browned quite well, but the glass pie plate has a number of other advantages.

Because you can see through a Pyrex plate, it's easy to judge just how brown the bottom crust has become during baking. With a metal pie plate, it's easy to pull the pie out of the oven too soon, when the bottom crust is still quite pale. A second feature we like about the traditional Pyrex plate is its wide rim, which makes the plate easier to take in and out of the oven and also provides more support for fluted edges than does a thin rim. Finally, because glass is nonreactive, you can store a pie filled with acidic fruit and not worry about metal giving the fruit an off flavor.

Pyrex pie plates do heat up more quickly than metal pie plates, so pies may finish baking a bit sooner than you expect, especially if you are following a recipe that was tested in a metal plate. All the times in our recipes are based on baking in a glass pie plate; if baking in metal, you may need to add two to three minutes for empty crusts and five minutes for filled pies.

DOUBLE-CRUST PIES

Apple and summer fruit pies—such as blueberry, cherry, peach, and strawberry-rhubarb, apple and summer fruit pies—require a top and bottom crust. For these pies, one piece of dough is fitted into the pan, the filling is added, the second piece of dough is placed on top, and the pie is baked.

As an alternative to our standard dough recipe for a double-crust pie, we also provide a recipe for a firmer pie dough. We accomplish this by reducing the total amount of fat in the recipe by about 30 percent. The reduction in fat results in some loss of flavor, but the dough's firmness makes it a better candidate for decorative edging such as crosshatching and scalloping since the dough is easier to shape. Since our firm dough has less fat, decorative edging holds up better in the oven.

Another decorative touch that can be used when making apple or summer fruit pies is the lattice-top crust. We recommend weaving the strips of dough together on a piece of parchment or waxed paper and then carefully sliding the lattice top over the filling.

PREBAKED PIE SHELLS

In apple and other fruit pies, which consist of two pieces of raw pie dough with filling sandwiched in between, the dough and filling are baked together. Many pies, however, such as pumpkin, lemon meringue, and cream, do not have a top crust. Rather, they start with a prebaked bottom crust, called a pie shell, which is filled and then sometimes baked again.

Baking unfilled pie pastry, commonly called blind baking, can turn out to be the ultimate culinary nightmare. Without the weight of a filling, a pastry shell set into a hot oven can shrink dramatically, fill with air pockets, and puff up like a linoleum floor after a flood. The result? A shrunken, uneven shell that can hold only part of the filling intended for it.

We took our favorite pie dough recipe (halving the quantities since we needed a single crust, not a double) and started to investigate the effects of resting the dough (in the refrigerator or the freezer), docking it (pricking the dough before it bakes), and weighting the crust as it bakes to keep it anchored in place. All three tricks are used by professional bakers to prevent the common problems encountered when blind-baking a crust.

CHILLING AND RESTING

We found that refrigeration does the best job of preventing shrinkage. Pastry shrinkage is caused by gluten. Simply put, when you add water to the proteins in flour, elastic strands of gluten are formed. The strands of gluten in the dough get stretched during the rolling process, and if they are not allowed to relax after rolling, the pastry will snap back like a rubber band when baked, resulting in a shrunken, misshapen shell. Resting allows the tension in the taut strands of dough to ease so that they remain stretched and do not shrink back when heated.

This process does not occur, however, when the dough is immediately placed in the freezer to rest after rolling. When frozen, the water in the crust solidifies, freezing the gluten in place so it is not free to relax. As a result, when the dough is baked, the tense, stretched strands of gluten snap back, causing the crust to shrink.

We might have concluded that pie dough should be refrigerated and not frozen if we hadn't noticed that the frozen crusts, although shrunken, were much flakier than the refrigerated crusts. Pastry is made up of layers of dough (protein and starch from the flour combined with water) and fat. Dough and fat have different heat capacities. When you place the pastry in the oven after freezing it (rather than just refrigerating it), the dough heats up and starts to set relatively quickly in comparison to the time it takes for the butter to melt and then vaporize; this is because butter has a much higher water content than the dough. As a result, by the time the water in the butter starts to turn to steam, the dough is well into its setting phase. The air spaces occupied by the frozen butter, which has now largely turned to steam, are held in place by the dough, which is far along in the baking process.

Dough that you have refrigerated, on the other hand, is not as well set by the time the butter vaporizes; hence the air pockets disappear, the soft dough simply sinking into the spaces left by the butter. We came to a simple conclusion: First refrigerate the pie shell to relax the gluten, thus solving the problem of shrinkage during baking, then pop the dough in the freezer to improve flakiness.

This bit of science led to one other fascinating discovery. It is common knowledge that lard or vegetable shortening such as Crisco produces a very flaky crust. In fact, as mentioned earlier in the chapter, we use a combination of butter and shortening in our recipe because of the improvement in texture over an all-butter crust. The explanation for this phenomenon is simple. Lard and Crisco melt more slowly than butter. Therefore, they retain their shape for even more time than butter does as the dough sets up, keeping the layers of pastry separated.

DOCKING AND WEIGHTING

While refrigerating the pie crust prevents shrinkage, it will not prevent ballooning, which can occur when air pockets form beneath the crust. Typically, bakers prevent the formation of air pockets by docking (or pricking) the dough with the tines of a fork before it goes into the oven. However, we found that docking was not necessary as long as the dough is weighted. Since weighting is a must—it not only prevents ballooning but keeps the shell, especially the sides, in place as it bakes—we do not dock pastry dough.

Some professional bakers swear by "official" pie weights, while others make do with rice or dried beans. We found that metal or ceramic pie weights do a better job than rice or beans. They are heavier and therefore more effective in keeping the pastry from puffing. Pie weights are also better heat conductors and promote more thorough browning of the pastry.

BAKING

We got the most even browning by baking in the middle rack at a constant temperature of 375 degrees. At higher temperatures, the pastry was prone to overbrowning and burned in spots, while lower temperatures caused the edges to brown well before the bottom. More important than temperature and placement, though, was cooking time.

There are two stages in prebaking. In the first stage, the dough is baked with a lining of aluminum foil and weights. This stage usually takes about 17 minutes; the objective is to cook the dough until it sets, at which point it can hold its shape without assistance. When the dough loses its wet look, turns from its original pale yellow to off-white, and begins to take on a very light brown color at the edges, the dough is set. If you have any doubts, carefully (the dough is hot) touch the side of the shell to make sure that the crust is firm. If you remove the pie weights too soon, the dough sides will slip down, ruining the pie shell.

In the second stage, the foil and weights are removed, and the baking continues. At this point, if you are going to fill the pie shell and then bake it again, as you would with pumpkin or pecan pie, you should bake it until it is just lightly browned, about 9 minutes. Pie shells destined for fillings that require little or no further cooking, such as cream and lemon meringue pies, should be baked for about 15 minutes.