Susan Purdy's new book was no piece of cake.
The baking teacher and author spent three years experimenting with recipes for low-fat baked goods. There were "unredeemable failures" that went directly from the ovens to the raccoons who live near her Roxbury, Conn., home. There were recipes that became obsessions, such as the lemon poppy seed cake that she tested 43 times before she felt it was worthy of the book.
"This book was much harder than the other books," Ms. Purdy says in classic understatement of the new "Have Your Cake and Eat It, Too" (Morrow, $25). An earlier book, "Piece of Cake" (Atheneum, $24.95, 1989), took two years, but "that was a question of finding the best examples of the most luscious cakes."
The challenge in developing recipes for "Have Your Cake and Eat It, Too" was to cut the saturated fat and cholesterol, yet save the flavor.
"Fat carries flavor, and fat contains flavor," Ms. Purdy says. "In baking, when you take out the fat, you have to put something back in for flavor and that affects the chemistry. Now you have a food chemistry problem. That's what took so long, to get delicious, reliable recipes."
Ms. Purdy, who is a baker, not a food scientist, did not realize how difficult these chemistry problems would be when she first became interested in writing such a book. After many years of using butter, eggs and chocolate with abandon, Ms. Purdy learned that her afternoon baking sessions with her mother would end when her mother was advised to go on a low-fat diet. She also quickly realized that it was just too cruel to take to a family party an angel-food cake for her mother and a rich chocolate cake for everyone else.
Ms. Purdy used her cake book as a starting point, analyzing the recipes and studying the role of the ingredients. She started by eliminating all of the fat. In some recipes, she replaced the fat with prune puree, which mimics the characteristics of fat. "I ended up with what I call a jogger's special cake," she says. "It was like a sneaker dipped in mud. It was flexible and rubbery and the outside was sticky."
The baker came to the quick realization that she couldn't completely eliminate fat. She decided to cut back on fat and go for flavor. "My goal was to make a good dessert that someone wanted to eat," she says. "The point is, if you're going to bother to bake, you should be rewarded. It should be something good, great."
The book's recipes passed Ms. Purdy's taste test: If tasters asked for more, it was good. Each recipe has a per-serving nutritional analysis and a "Light Touch" note at the end, explaining the differences between the original recipe and Ms. Purdy's adaptation.
For example, her classic carrot cake recipe derives more than half of its calories from fat -- and that doesn't include the traditional cream cheese frosting that adds 322 calories and 18 grams of fat to each slice. The new version gets only 15 percent of its calories from fat. Ms. Purdy cut the oil to 3 tablespoons, substituted egg whites for whole eggs and eliminated the nuts, which are high in fat. She keeps the cake light with a pineapple glaze instead of frosting.
Some recipes couldn't be altered, however. Creme brulee made with egg whites and non-fat milk was just too far from the real thing. Ms. Purdy has common-sense words for dealing with these recipes that fight adaptation: "I think you should eat creme brulee once in a while and get on with life."
Ms. Purdy shares many fat-cutting tips that she learned by trial and error or from Shirley Corriher, an Atlanta-based food scientist she called for technical help. But, she says, there are no hard-and-fast rules for low-fat baking that work in every recipe. She believes her recipes are well-developed and reliable and could be used as a guide for adapting a home baker's favorite recipe.
But Ms. Purdy's three inch-thick file on the lemon poppy seed cake shows that adapting recipes is difficult. "I cut down on the amount of poppy seeds because they are high in fat, and I folded a meringue into the batter," she says. "It would bake fine, but as it cooled, the center would collapse." Between Ms. Purdy and Ms. Corriher, they managed to alter the meringue so the recipe worked.
While Ms. Purdy's other cookbooks aren't collecting dust on her shelves, she says working on this project has raised her consciousness. "Every time I look at a recipe, I'm aware of the amount of fat," she says.
After testing 600 to 700 recipes, Ms. Purdy included about 200 recipes in the book. They cover all types of baking and baked goods: breakfast coffee cakes, muffins and quick breads; cakes, cheesecakes and pudding cakes; pies and tarts; cookies and biscotti; miscellaneous desserts; and frostings. There also are some gluten-free recipes.