Kneading dough is a process primarily used in bread-making to develop gluten, a protein network that gives bread its structure and texture. While kneading is not necessary for all bread recipes, it is typically done for yeast-based breads like artisan loaves or baguettes.
When dough is kneaded, it activates the gluten proteins present in the flour. Gluten forms long strands that create a network, giving the bread its elasticity and chewiness. Kneading helps to align these strands and develop the gluten structure, resulting in a well-risen, airy bread with a desirable crumb.
On the other hand, cakes and cookies are typically made with a different type of dough or batter. The goal in these recipes is to create a tender and delicate texture rather than a chewy one. Kneading the dough for cakes or cookies would actually develop gluten too much, resulting in a dense and tough texture, which is not desired in these baked goods.
Cake batters usually contain a higher proportion of fat, sugar, and liquid, which inhibit gluten development. They rely more on leavening agents like baking powder or baking soda to create the desired rise. Cookies also have a different ratio of ingredients and are often made with a higher proportion of fat, sugar, and eggs, which contribute to their tender and crumbly texture.
So, while kneading is essential for bread-making to develop gluten and create the desired structure, it is not necessary for cakes or cookies, where a different texture is desired, and gluten development is generally minimized.