The beauty of a lemon chiffon pie lies in its classic simplicity. Its light mousse filling relies on gelatin, eggs and whipping cream for volume. You make the filling separately and then combine it with the crust. This is one dessert that doesn't need baking, making it an ideal choice for hot weather. Leave the oven off and stick with the stovetop for this one.
The filling in lemon chiffon pie is a sort of custard, made by thickening gelatin, lemon juice and egg yolks over simmering water. To ensure creamy, consistent results, you must stir constantly while the eggs are thickening. If you baked a lemon chiffon pie, rather than cooking it in a double boiler, you couldn't stir it. The end result would be tough lumps resembling scrambled eggs -- definitely not the results you're seeking.
If you've never made a custard before, the process though unfamiliar is actually quite simple. Your kids can even help with some of the steps. Soften unflavored gelatin in a small bowl of cold water. Place a larger bowl over a pot of simmering water. In this bowl, combine sugar, lemon juice, lemon peel, egg yolks and salt. Cook the egg yolk mixture over the water, whisking or stirring constantly. The eggs will cook without scrambling. The mixture is done when it coats a spoon. Stir in the gelatin water and cool the egg mixture over a bowl of ice water. Then gently fold in beaten egg whites and freshly whipped cream.
You stirred the egg yolk mixture constantly and you still have lumps. Don't worry. There are a few quick fixes for this problem. First, remove the egg yolk mixture from the heat and whisk it vigorously. This usually removes the lumps. If lumps remain, strain the mixture through a colander. In the future, turn the heat down a bit on the simmering water. Lumps sometimes happen when the water is so hot that the eggs cook quickly in spite of your stirring. Once you master this technique, you can use it to make homemade pudding, custards and ice cream.
The one time you'll use the oven when making lemon chiffon pie is to bake the crust. If you're using a regular pie crust, prick the crust with a fork and place a few beans or a weight on the crust so it doesn't rise during baking. It needs only six to 10 minutes to bake. A cookie crumb crust is even simpler. Grind gingersnap or vanilla cookies in a food processor to make fine crumbs. Mix the crumbs with enough butter to form a coarse dough. Press the dough into a pie tin and bake until the crust is golden brown -- typically five to eight minutes, depending on your oven. Allow the crust to cool completely before adding the filling. If you use a pre-baked pie crust, you won't need the oven at all.
Because lemon chiffon pie contains eggs and cream, it should be refrigerated. The pie can be refrigerated for 24 hours or frozen for up to three months. Don't put it in the oven to thaw it though -- thaw in the refrigerator for 24 hours. Allow refrigerated pies to come to room temperature for 30 minutes before serving.