Raw milk or unpasteurized milk is milk that has not undergone pasteurization, a process of heating foods to kill pathogens for safe consumption and extension of shelf life.
Proponents have said that raw, unpasteurised milk has better flavor, and also provides better nutrition, contributions to the building of a healthy immune system and protection from allergies. However, no clear nutritional or health benefit of unpasteurised milk has been found, and there is consensus in the medical community that dangerous milk-borne diseases may be contracted from it and from products such as cheese made with it. Substantial evidence of this increased risk for no clear benefit has led countries around the world to either prohibit or regulate the sale of raw milk and raw milk products.
In countries where it is available for sale, its availability and regulations vary. In the European Union, individual member states can prohibit or restrict the sale of raw milk, but it is not banned throughout the EU; in some member states, the sale of raw milk through vending machines is permitted, though packaging typically instructs consumers to boil before consumption.
History of raw milk and pasteurization
Humans first regularly consumed the milk of other mammals following the domestication of animals during the Neolithic Revolution or the development of agriculture. This development occurred independently in several places around the world from as early as 9000–7000 BC in Mesopotamia to 3500–3000 BC in the Americas. The most important dairy animals—cattle, sheep and goats—were first domesticated in Mesopotamia, although domestic cattle have been independently derived from wild aurochs populations several times since. From there, dairy animals spread to Europe (beginning around 7000 BC but not reaching Britain and Scandinavia until after 4000 BC), and South Asia (7000–5500 BC).
Pasteurization is widely used to prevent infected milk from entering the food supply. The pasteurization process was developed in 1864 by French scientist Louis Pasteur, who discovered that heating beer and wine was enough to kill most of the bacteria that caused spoilage, preventing these beverages from turning sour. The process achieves this by eliminating pathogenic microbes and lowering microbial numbers to improve shelf life.
After sufficient scientific study led to the development of germ theory, pasteurization was introduced in the United States in the 1890s. This move successfully controlled the spread of highly contagious bacterial diseases, including E. coli, bovine tuberculosis, and brucellosis, all transmitted to humans through the drinking of infected raw milk. In the early days after the scientific discovery of bacteria, there was no product testing to determine whether a farmer's milk was safe or infected, so all milk was treated as potentially contagious. After the first tests were developed, some farmers took steps to prevent their infected animals from being killed and removed from food production, sometimes even falsifying test results to make their animals appear free of infection. Advances in the analysis of milk-borne diseases have enabled scientists to track the DNA of infectious bacteria in raw milk to the cows on the farms that supplied it.
The recognition of many potentially deadly pathogens, such as E. coli 0157 H7, Campylobacter, Listeria, and Salmonella, and their possible presence in poorly produced milk products has led to the continuation of pasteurization. The U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, and other health agencies of the United States strongly recommend that the public not consume raw milk or raw milk products. Young children, the elderly, people with weakened immune systems, and pregnant women are particularly susceptible to infections originating in raw milk.
Uses Some cheeses are produced with raw milk, although local statutes vary regarding required health precautions. There have been many reports of infections caused by raw milk cheese. Cumulative international list of reports of infections from cheese made with raw milk, updated as required.
The first camembert was made from raw milk, and the (AOC) variety "Camembert de Normandie" (approximately 10% of all camembert production) is required by law to be made only with unpasteurized milk. Raw milk cheeses have been described as having richer taste and aroma, and as being of high value for consumers.Meunier-Goddik, L.; Waite-Cusic, J. Consumers Acceptance of Raw Milk and Its Products. Raw Milk: Balance Between Hazards Benefits; Nero, L.A.; de Carvalho, A.F. Academic Press: San Diego, CA, USA, 2019; pp. 311-350.O’Sullivan, O.; Cotter, P.D. Microbiota of Raw Milk and Raw Milk Cheeses. Cheese; McSweeney, P.L.H.; Fox, P.F.; Cotter, P.D.; Everett, D.W. Academic Press: San Diego, CA, USA, 2017; Volume 1, pp. 301-316. Many modern cheesemakers, however, use pasteurized milk for safety, regulations, or convenience.
A thick mixture known as syllabub was created by milkmaids squirting milk directly from a cow into a container of cider, beer or other beverage.
Raw yak milk can ferment overnight to become a yoghurt-like substance, which can then be churned into yak butter.
Health effects
Infectivity The potential pathogenic bacteria from raw milk include tuberculosis (TB), diphtheria, typhoid, Campylobacter, Listeria, Brucella, E. coli, Salmonella, and streptococcal infections and make it potentially unsafe to consume. Raw milk may also contain parasites such as Cryptosporidium. Groups of people that are at especially high risk for developing illness from consuming raw milk include children under the age of 5, adults over the age of 65, pregnant women, and people who have a weakened immune system. Many of these disorders are often, despite the advances in modern medicine, hard to diagnose (examples include TB and Brucellosis), and sometimes hard to treat.
Moreover, a review published in 2012 by the Belgian Federal Agency for the Safety of the Food Chain alongside experts from several Belgian universities and institutions concluded that "raw milk poses a realistic health threat due to possible contamination with human pathogens. It is therefore strongly recommended that milk should be heated before consumption."
Even with precautions and cold storage (optimally ),p. 17 in: raw milk has a shelf life of 3 to 5 days.
A 2024 study showed that the Influenza A virus can survive in refrigerated raw milk for several days.
The 2020–2025 H5N1 outbreak spread to dairy cattle in 2024, and influenza was detected in commercial milk supplies in the United States. The United States Food and Drug Administration warned (as has been its long-standing position) that consumers should avoid raw milk because its ability to transmit influenza to humans is unknown. Pasteurization is believed to inactivate the virus. A high mortality rate was observed among cats that drank raw milk from cows displaying symptoms of H5N1 infection.
Epidemiology Before pasteurized milk was adopted in the US, public health officials were concerned with cow milk transmission of bovine tuberculosis to humans, with an estimated 10% of all tuberculosis cases in humans being attributed to milk consumption. Along with specific diseases, officials continue to be concerned about outbreaks. With modern pasteurization and sanitation practices, milk accounts for less than 1% of reported outbreaks caused by food and water consumption. By comparison, raw milk was associated with 25% of all disease outbreaks from food/water during the time before World War II in the U.S. From a public health standpoint, pasteurization has decreased the percentage of milk-associated food/waterborne outbreaks.
Between 2007 and 2016, there were 144 outbreaks connected to raw milk consumption in the United States. Because raw milk production skips the pasteurization process, the germs that are normally removed remain in the milk product. Exposure to raw milk containing harmful bacteria raises the risk of serious infection, including Campylobacter, Cryptosporidium, E. coli, Listeria, and Salmonella. Additionally, depending on the severity of the infection, there may be further threats to human health. Infection has the potential to induce serious illnesses such as Guillain-Barré syndrome and Hemolytic–uremic syndrome (HUS). These illnesses can lead to severe health complications, such as kidney failure, strokes, and death.
Outbreaks have occurred from consuming food products made with raw milk. One of the potential pathogens in raw milk, Listeria monocytogenes, can survive pasteurization and contaminate post-pasteurization environments. Milk and dairy products made with that milk then become recontaminated. Consistent contamination persists due to bacterial survival in biofilms within the processing systems.
One food item that commonly uses raw milk in its production is cheese. Several different types of cheeses made with raw milk are consumed by a large portion of the United States population, including soft cheeses. Since Gouda cheese is aged for 60 days before its sale it had been hypothesized that no bacteria would then survive, but a review study published in the Journal of Food Protection showed that E. coli O157:H7 can persist through the aging period of Gouda cheese. The study's evidence included three outbreaks before 2013 associated with this specific strain of E. coli in Gouda.
Prevention of outbreaks
A 2018 study found raw milk to be responsible for almost three times more cases than any other food-borne illness.Alegbeleye OO, Guimaraes JT, Cruz AG, Sant’Ana AS. Hazards of a 'healthy' trend? An appraisal of the risks of raw milk consumption and the potential of novel treatment technologies to serve as alternatives to pasteurization. Trends Food Sci Technol 2018;82:148–66. 10.1016/j.tifs.2018.10.007 [DOI] [Google Scholar] Public health strategies aimed at reducing the risks associated with raw milk consumption focus on individual and systemic safeguards. Pasteurization is the most effective method of preventing food-borne illnesses from raw milk. With public health implications in mind, health professionals need to understand the need for pasteurization. Introducing on-farm food safety training programs for raw milk producers can be an effective risk management option.Silveira, A., Carvalho, J. P., Loh, L., & Benusic, M. (2023). Public health risks of raw milk consumption: Lessons from a case of paediatric hemolytic uremic syndrome. Canada communicable disease report = Releve des maladies transmissibles au Canada, 49(9), 375–379. https://doi.org/10.14745/ccdr.v49i09a03 Infections in animals can be prevented by vaccination and regular veterinary check-ups. Organizations, including the World Health Organization and the Food and Drug Administration, consistently advise against consuming raw milk due to the associated health risks.
Nutrition and allergy "With the exception of an altered organoleptic [flavor] profile, heating (particularly ultra-high temperature and similar treatments) will not substantially change the nutritional value of raw milk or other benefits associated with raw milk consumption."
Raw milk advocates, such as the Weston A. Price Foundation, say that raw milk can be produced hygienically and that it has health benefits that are destroyed in the pasteurization process. Research has found no evidence to support this claim, and data shows only very slight differences in the nutritional values of pasteurized and unpasteurized milk.
Proponents of raw milk in the US have said that while pasteurization may kill dangerous bacteria, it also kills beneficial bacteria not present in pasteurized milk, but the United States Food and Drug Administration has stated that this is false and that pasteurizing milk does not destroy any of its nutritional value.