Preparation of food has developed as has production. Like food-production, food-preparation is now studied. The methods of early times and those of every land are now more generally known and practiced. Many methods arising where a food so grows as to be a chief article of diet are carried with it as the people that first used it move from place to place, or as it is transported or more extensively cultivated, so more widely eaten.

Most early methods were developed by life-experience in preparing food. These are now found by scientific experiment to be ways of treating food-materials which make food not only more palatable but also usually more digestible and nutritious. Cooking - the application of dry or moist heat to food - changes different foods differently. Heat tends to break up and render tender vegetable fiber, whereas it toughens animal. Prolonged slow cooking of grains and rapid slight cooking of tender meats have always been practiced, because these foods when thus cooked seemed better. Science has now learned why.

Much that science has learned about the exact effect of different methods of treating different foods, together with the tendency toward factory production of all products needed for human consumption, has led to extensive preparation of food outside of the home. As the storage of food arose with the general transportation of it, so the preservation of food has arisen, likewise the practice of factory preparation. The advantage claimed for transported food has been variety of food everywhere at all seasons with less labor for the consumer; this is claimed also for factory-prepared food. The disadvantage of the former, namely decreased freshness, is the disadvantage of the latter. The distinct danger of each will be discussed elsewhere.

Food-transportation makes more food-traders than producers. Factory preparation decreases the preparers of food.