Q. We received as a wedding gift a lovely silver pie holder with a ten-inch Pyrex pie pan. Over the years, I have tried to find recipes for 10-inch pie pans but have been unsuccessful. I need a formula for increasing both filling and crust. Can you help.
A. Pie recipes are usually based on either 8-inch or 9-inch pie pans. To make a conversion is simply a matter of algebra. In the chart below are some conversion factors for scaling up pie recipes. You can take these factors and multiply them by the volume or weight of each ingredient. Small inaccuracies due to rounding up (for example, rounding 3.7 cups to 3 3/4 cups) will not harm a recipe's results.
In general, it is better to round up than to round down. The amount that you round up should not exceed 10 percent of the original number. So, if you round 3.7 cups of flour to 3.75 (3 3/4 cups), the difference, 0.05, divided by the original number, 3.7, gives you a rounding error of 0.013, or 1.3 percent.
Smaller numbers can generate much larger rounding errors. For example, should you, in the process of scaling up a pie dough recipe, round 1.1 teaspoons of salt to 1 1/2 teaspoons instead of 1 1/4 teaspoons, you would obtain a much saltier dough than the original recipe produced. The difference (0.4 teaspoons) divided by the original number (1.1 teaspoons) yields a 37 percent rounding error. If you were to round the salt to 1 1/4 teaspoons, though, the rounding error would be only be 0.14 or 14 percent. The dough would only be marginally saltier and you would still have the wherewithal (the spoon, that is) to measure it.
Multiply any one of the following factors by the amount of each ingredient in the desired recipe. Then round up as little as possible while keeping the number measurable.
If the U.S. Congress had passed the metric conversion law 20 years ago as promised, we wouldn't be in this mess today.
Q. Most recipes using cornmeal -- corn bread, spoonbread, fritters and hushpuppies, for example -- call for a tablespoon or two of sugar or molasses. What role does the sweetener play? Can it be left out?
A. The sweetener is added only for taste. Cornmeal and corn flour have a pleasant flavor if a hint of sweetener is added. Otherwise, the bitterness of some of the corn's proteins is more apparent.
Q. I make a mean cream pie, but the moisture from the filling causes a soggy crust. Can you explain why?
A. You don't mention how you make the filling. There are several important procedural points:
1. The crust must be prebaked and cool.
2. The filling's moisture will soak in less if you precook the filling before pouring it into the pie shell. This is because the filling contains a lot of free water -- water not bound by sugar or starch and therefore available to soak into the crust. If you precook the filling, the cornstarch granules remove most of that water.
3. And if you are precooking the filling, don't transfer it to the baked shell until the filling is cool. At a high temperature, the remaining free-water molecules are still very energetic and could well migrate to the shell and soften it.
Here's a version of the recipe you enclosed, this time including instructions: VANILLA CREAM PIE (Makes one 8-inch pie)
3 egg yolks
3/4 cup sugar
5 tablespoons cornstarch
1 1/2 cups boiling milk
2 tablespoons butter
1 teaspoon vanilla
1 fully prebaked 8-inch pie shell
Whipped cream for serving
Using a whisk, beat the egg yolks and sugar until light -- about 3 minutes. Stir in the cornstarch until well incorporated. Bring the milk to a boil and pour over the yolk-sugar-starch mixture all at once. Set the pan down and immediately whisk this together (due to the sugar's protecting influences, the yolk won't curdle -- unless you're really slow).
Pour this mixture back in the saucepan and bring back to the boil over high heat, stirring regularly with the whisk. When the edges begin to thicken and boil, turn the heat to low. Stir continually to prevent scorching.
When the filling has fully thickened (after about 3 minutes of boiling) dot butter over the surface of the hot filling (butter will form a greasy layer which will prevent the formation of a skin). When filling has cooled to lukewarm, whisk butter into the filling, adding the vanilla. Transfer to the shell. Refrigerate at least 2 hours before decorating with whipped cream, slicing and serving.