This article is about cooking corn on the cob in the microwave preparation of food. For a general outline, see Outline of food preparation.

For varied styles of international food, see cuisine. Cooking, cookery, or culinary arts is the art, science and craft of using heat to prepare food for consumption. Types of cooking also depend on the skill levels and training of the cooks. Cooking is done both by people in their own dwellings and by professional cooks and chefs in restaurants and other food establishments.

Preparing food with heat or fire is an activity unique to humans. Archeological evidence of cooking fires from at least 300,000 years ago exists, but some estimate that humans started cooking up to 2 million years ago. The expansion of agriculture, commerce, trade, and transportation between civilizations in different regions offered cooks many new ingredients. Phylogenetic analysis suggests that early hominids may have adopted cooking 1.

Recently, the earliest hearths have been reported to be at least 790,000 years old. Communication between the Old World and the New World in the Columbian Exchange influenced the history of cooking. In the seventeenth and eighteenth centuries, food was a classic marker of identity in Europe. In the nineteenth-century “Age of Nationalism” cuisine became a defining symbol of national identity. The Industrial Revolution brought mass-production, mass-marketing, and standardization of food.

Factories processed, preserved, canned, and packaged a wide variety of foods, and processed cereals quickly became a defining feature of the American breakfast. This section does not cite any sources. Most ingredients in cooking are derived from living organisms. Vegetables, fruits, grains and nuts as well as herbs and spices come from plants, while meat, eggs, and dairy products come from animals.

Mushrooms and the yeast used in baking are kinds of fungi. Naturally occurring ingredients contain various amounts of molecules called proteins, carbohydrates and fats. They also contain water and minerals. Cooking involves a manipulation of the chemical properties of these molecules. The interaction of heat and carbohydrate is complex. Long-chain sugars such as starch tend to break down into more digestible simpler sugars.

An emulsion of starch with fat or water can, when gently heated, provide thickening to the dish being cooked. In European cooking, a mixture of butter and flour called a roux is used to thicken liquids to make stews or sauces. Types of fat include vegetable oils, animal products such as butter and lard, as well as fats from grains, including maize and flax oils. Fats are used in a number of ways in cooking and baking. Edible animal material, including muscle, offal, milk, eggs and egg whites, contains substantial amounts of protein. Water is often used to cook foods such as noodles. Cooking often involves water and water-based liquids.

Alternatively, the foods themselves can release water. A favorite method of adding flavor to dishes is to save the liquid for use in other recipes. There are very many methods of cooking, most of which have been known since antiquity. These include baking, roasting, frying, grilling, barbecuing, smoking, boiling, steaming and braising. A more recent innovation is microwaving.

Various methods use differing levels of heat and moisture and vary in cooking time. The method chosen greatly affects the result because some foods are more appropriate to some methods than others. A cook sautees onions and green peppers in a skillet. 6 billion people cook using open fires or inefficient stoves using kerosene, biomass, and coal as fuel.

These cooking practices use fuels and technologies that produce high levels of household air pollution, causing 3. 1 percent of injuries in United States related to knives, ended in hospital admissions. To prevent those injuries there are protections such as cooking clothing, anti-slip shoes, fire extinguisher and more. Cooking can prevent many foodborne illnesses that would otherwise occur if the food is eaten raw. When heat is used in the preparation of food, it can kill or inactivate harmful organisms, such as bacteria and viruses, as well as various parasites such as tapeworms and Toxoplasma gondii. The sterilizing effect of cooking depends on temperature, cooking time, and technique used. Cooking increases the digestibility of many foods which are inedible or poisonous when raw.

Food safety depends on the safe preparation, handling, and storage of food. A raw tomato sauce with olives, celery, spinach and walnuts on zucchini noodles. Proponents of raw foodism argue that cooking food increases the risk of some of the detrimental effects on food or health. They point out that during cooking of vegetables and fruit containing vitamin C, the vitamin elutes into the cooking water and becomes degraded through oxidation. German research in 2003 showed significant benefits in reducing breast cancer risk when large amounts of raw vegetable matter are included in the diet.