Is an excellent medium for microbial growth, and when stored at ambient temperature bacteria and other pathogens soon proliferate. before the wide spread urban growth caused by industrialization, people kept dairy cows even in urban areas. and the short time between milking and consumption minimized the disease risk of drinking raw milk. however, the often days-old raw milk began being recognized as a source of disease. pasteurization of milk was suggested by franz von sox let in 1886. it is the main reason for milk's extended shelf life. high-temperature, short-time pasteurized milk typically has a refrigerated shelf life of two to three weeks, whereas ultra-pasteurized milk can last much longer, sometimes two to three months. when ultra-heat treatment (uht) is combined with sterile handling and container technology (such as aseptic packaging), it can even be stored unrefrigerated for 6 to 9 months. proponents of unpasteurized milk make the argument that if milk is obtained from humanely raised cows that are grass fed and handled hygienically, then there is little problem with disease. however, raw milk can become contaminated in a number of ways: by coming into contact with cow feces or bacteria living on the skin of cows, from an infection of the cow's udder, or from dirty equipment, among others. according to the government of new zealand, the centers for disease control (cdc) says improperly handled raw milk is responsible for nearly three times more hospitalizations than any other food borne disease outbreak, making it one of the world's most dangerous food products.
