" Would you explain to me the scientific process of baking a pound cake? "

Dear Anne and Sue,

I enjoy baking. I make pound cakes for family and friends quite frequently. Would you explain to me the scientific process of baking a pound cake?

—From Pam, Miami, Florida

Hi Pam,

There's no doubt that cake making falls clearly into the realm of science, when you consider that bakers routinely change one kind of matter into another. Originally, pound cakes were made of one pound each of just four ingredientsbutter, sugar, eggs, and flour. Those were the days when cooks relied on muscle power and a wooden spoon for beating.

Whether using a wooden spoon or electric mixer, the rationale for beginning by beating, or "creaming," butter or margarine, is still the sameto incorporate air bubbles. Watch the fat become lighter in color as you beat in air. Then as you sprinkle in sugar and continue to beat, the sugar's jagged crystals drag in even more air. As the cake bakes, these tiny air bubbles expand in heat, lightening the texture and making the cake rise.

Today's pound cakes hardly resemble their more humble predecessors, with additional ingredients like chocolate, hazelnuts, lemon, and poppy seeds. And they also soar to greater heights with chemical leavens. If you look at the composition of baking soda, you'll find it is made up of sodium, carbon, hydrogen, and oxygen. When mixed with an acid-such as buttermilk or lemon juice, a chemical reaction takes place. The atoms in the baking soda and acid quickly recombine and carbon dioxide is released, functioning as a leaven along with the air you've added through beating.

During baking, as air, carbon dioxide, and steam lift the batter to its maximum height, proteins in the eggs and flour coagulate, starch from the flour reinforces the structure, and the framework sets.

There's logic to these old methods that work so well. In fact, the pound cake is the precursor of today's classic "butter cake."

Anne and Sue