What is Cooking? In its most basic of definitions cooking is the application of heat to a food item or items. Cooking, however does much more than just apply heat to food. Because of the heat applied to food items those items change internally according to the type of heat applied, how much heat applied and for how long.
For instance, sugars in food turn brown or caramelize when heat is applied such as when baking some bread the sugars in the flour turn brown when the bread reaches close to done.
Starches will absorb water like sponges in the example of cooking rice and the rice absorbs all of the water you’ve measured out prior to cooking.
Proteins will gain structure or get firm when heat is applied. When you are cooking a steak on the grill a well done steak is firm to the touch while a rare steak will give when pressed with a finger.
The application of heat to a food item that contains water will evaporate some of that water and will, in the case of some food items, cause them to shrink in size as with a hamburger cooked on the grill.
Fats, butters and oils will liquefy when heated and eventually smoke and burn if too much heat is applied.
Fibers in vegetables soften when cooked so celery and carrots actually soften when cooked.
The color of food is affected by the application of heat to food items. Have you ever sautéed Swiss chard which turns a bright green when cooked properly only to yield to a wilted structure and a brown color if cooked too long.
Vitamins and minerals are cooked out of food the longer a food item is heated. That is why steaming vegetables is a more nutritious way of preparing vegetables than parboiling.
Anyone can apply heat to food for human consumption. The art and skill of cooking comes in play when you know what type of heat to apply, for how long and what it will do to the item or items being cooked.