How do cookies rise while baking?

Cookies rise during baking thanks to a combination of two main mechanisms:

1. Leavening agents:

* Baking soda: This chemical leavening agent reacts with acidic ingredients in the cookie dough, releasing carbon dioxide gas bubbles. These bubbles get trapped within the dough, causing it to expand and rise.

* Baking powder: This is a double-acting leavening agent, meaning it releases gas during both the mixing process and when exposed to heat. It contains baking soda, an acid, and a starch. The reaction between the baking soda and acid releases gas during mixing, and the heat of the oven triggers further gas production, leading to more rise.

2. Steam:

* As the cookie dough bakes, the moisture within it turns into steam. This steam expands and creates air pockets within the cookie, contributing to its rise.

The balance between these two factors determines the final rise of the cookie:

* High leavening: Cookies with a high proportion of leavening agents will rise more and have a lighter, airier texture.

* Low leavening: Cookies with less leavening will rise less and have a denser, chewier texture.

Other factors influencing cookie rise:

* Fat content: Fats in the dough trap air bubbles, contributing to rise.

* Sugar content: Sugar helps to retain moisture, promoting steam production and rise.

* Mixing technique: Overmixing can develop gluten, making the dough tough and reducing rise.

Understanding these factors allows you to adjust your cookie recipe to achieve the desired texture and rise for your cookies.