Step 2: Flour, A Rising Agent, and A Binding Agent
Flour is a stabilizer and thickener and controls how much the cookie rises. It holds the cookie together, providing it with its structure. If you use too little flour your cookie won’t keep its shape but if you use too much you’ll end up with a thick tasteless cookie. Also, different types of flour result in different cookie textures. For example, cake flour provides a cake-like texture (go figure!). All-purpose flour is the standard flour used most often.
The rising agent or leavener most commonly used is either baking soda or baking powder. If you use baking soda, your recipe must include another acidic ingredient, like sour cream, lemon juice, or buttermilk. On the other hand, baking powder has its own built-in acid. Baking soda increases browning and spreading, resulting in a flatter cookie. Baking powder will give you a puffier cookie.
Binding agents are the liquid in the recipe that hold the cookie together. Examples of binding agents are eggs, milk, honey, and fruit juice. Cookies with more eggs will rise more and spread less. If you want a crispier cookie, you can replace a whole egg with just an egg white. Or, if you want a chewier cookie, you can replace a whole egg with just an egg yolk.