The principles of baking involve wet ingredients, dry ingredients, leavening agents, flavoring, heat, and different mixing methods. Baking requires accurate measurement of ingredients, and recipes are actually formulas that give a ratio of how much of each ingredient must be in the finished product. Flour, sugar, eggs, milk, butter, and flavourings are the basic ingredients needed to create different baked goods. The protein present in flour gives structure and helps contain gases within the dough given off by leavening agents. The amount of time, temperature, humidity, air flow, and heat flux are the main parameters involved in the baking process.