Frozen foods are ubiquitous in American supermarkets, and are increasingly a part of the food industry worldwide. Fruits and vegetables are usually frozen within hours of being picked, and when thawed, they are very close to fresh in taste and texture. The frozen meal is increasingly popular in time-starved American households. If the meal can be heated in a microwave, total time from freezer to table can be less than five minutes. Besides offering fresh taste and convenience, freezing is also a safe method of preservation, as most pathogens are inactivated at low temperatures.
The frozen food industry dates back to the early years of the twentieth century, when some foods were preserved by the so-called cold-pack method. Food handlers would wash and sort fruits or vegetables, then pack them in large containers holding from 30-400 lb (14-180 kg). The large containers were placed in a cold storage room for several days until the mass was frozen solid. Cold pack foods did not have the quality of modern frozen foods because of the time it took for the food to freeze. In slow freezing, the water in the food crystallizes, forming large needles of ice. These shards of ice destroy cells walls, and so when the food is thawed, it has deteriorated in taste and texture. The innovation that made the current frozen food industry possible was the invention of quick freezing by Clarence Birdseye.