Unpasteurized milk, commonly called raw milk, is milk that has not been heated to kill bacteria and other microorganisms. It goes from the animal to the bottle with no thermal processing step in between. Less than 1 percent of Americans drink it regularly, though that number has grown in recent years as interest in unprocessed foods has increased. The debate around raw milk is unusually heated for a grocery item, touching on food safety, personal freedom, and competing ideas about nutrition.
How Pasteurization Works and What Raw Milk Skips
Pasteurization heats milk to a specific temperature for a set period, typically around 161°F for 15 seconds, which is enough to destroy most disease-causing bacteria. The process was widely adopted in the early 20th century and is credited with dramatically reducing milk-borne illness. Raw milk skips this step entirely. After a cow (or goat, sheep, or other dairy animal) is milked, the milk is chilled and bottled but never heated.
Proponents value raw milk for its taste, which many describe as richer and more complex than the pasteurized version. They also cite a preference for minimal processing and a belief that heating damages nutrients and beneficial compounds naturally present in fresh milk.
Nutritional Differences Between Raw and Pasteurized Milk
The nutritional gap between raw and pasteurized milk is real but smaller than many advocates suggest. A systematic review and meta-analysis found that pasteurization significantly reduces levels of vitamins B1, B2, C, and folate. Vitamins B12 and E also decreased, while vitamin A actually increased after heating. Vitamin B6 showed no statistically significant change.
These losses sound concerning in isolation, but context matters. Milk is not a major dietary source of vitamin C or folate for most people. You get far more of both from fruits, vegetables, and grains. The vitamins where milk does contribute meaningfully to your diet, like B12 and riboflavin (B2), show relatively modest declines. The core nutritional profile of milk, its protein, calcium, and fat content, remains essentially unchanged by pasteurization.
Raw milk also contains active enzymes that pasteurization destroys. Some advocates believe these enzymes, particularly one called lactase, make raw milk easier to digest for people with lactose intolerance. Scientific evidence for this claim is limited, and most researchers note that the amount of lactase naturally present in cow’s milk is too small to meaningfully aid digestion.
Bacteria in Raw Milk: Beneficial and Dangerous
Raw milk is a living food in the truest sense. Researchers have identified at least 22 species of lactic acid bacteria in raw cow’s milk, including strains used in yogurt and cheese production. Total bacterial counts in raw milk samples range widely depending on the farm and region, with one study recording counts around 4.63 log CFU/mL (roughly 40,000 bacteria per milliliter) in samples from certain herds. These communities of microorganisms are part of what gives raw milk its distinctive flavor and what supporters point to when they describe it as a probiotic food.
The problem is that raw milk can also harbor bacteria that cause serious illness. The CDC identifies Campylobacter, Salmonella, E. coli, Listeria, Brucella, and the parasite Cryptosporidium as organisms that have been found in unpasteurized milk. There is no reliable way to tell safe raw milk from contaminated raw milk by taste, smell, or appearance.
Symptoms of raw milk-related illness typically include diarrhea, stomach cramps, and vomiting. In rarer cases, the consequences are far worse. E. coli infections can trigger hemolytic uremic syndrome, which leads to kidney failure. Campylobacter infections can cause Guillain-Barré syndrome, a condition that results in paralysis. Deaths have occurred. Children under 5, adults over 65, pregnant women, and anyone with a weakened immune system face the highest risk of severe outcomes.
Outbreak Numbers Tell a Clear Story
The statistics on raw milk and foodborne illness are striking. A CDC-cited study covering 2009 to 2014 found that unpasteurized milk and cheese, consumed by roughly 3.2 percent and 1.6 percent of the population respectively, caused 96 percent of all illnesses linked to contaminated dairy products. That disproportion is the central public health argument against raw milk: a tiny share of consumption produces nearly all of the harm.
This doesn’t mean every glass of raw milk will make you sick. Most won’t. But the odds of a contaminated batch reaching consumers are significantly higher than with pasteurized products, and when contamination does occur, there is no safety net.
Bird Flu and Raw Milk: A Recent Concern
The H5N1 bird flu virus added a new layer to the raw milk debate in 2024 and 2025. After the virus spread through U.S. dairy herds, the USDA issued federal orders requiring mandatory testing of raw, unpasteurized milk and testing before interstate movement of dairy cattle. The CDC detected H5N1 viral RNA in retail milk products, though pasteurization effectively inactivates the virus.
The CDC has explicitly warned against drinking raw milk contaminated with H5N1 as a way to build immunity, a claim that circulated on social media. Consuming raw milk with live virus could make you sick; it will not produce the kind of controlled immune response a vaccine provides. Surveillance through 2025 identified multiple new spillover events of the virus into dairy herds, underscoring that this risk is ongoing.
How Careful Producers Reduce Risk
Farms that sell raw milk legally often follow safety protocols that go well beyond what conventional dairy operations use, since they cannot rely on pasteurization as a final safeguard. The Raw Milk Institute (RAWMI) in the United States requires at least monthly testing of milk for coliform bacteria and total bacterial counts. Their benchmark limits are strict: coliform counts of 10 or fewer per milliliter and total plate counts of 5,000 or fewer per milliliter.
In the European Union, general standards for raw milk production require no detectable common pathogens, total plate counts below 50,000 per milliliter, and coliform counts under 100 per milliliter. Germany’s “Vorzugsmilch” program, one of the oldest legal raw milk systems in Europe, mandates monthly farm visits by veterinary health inspectors, individual cow sampling, and laboratory testing of each batch.
These protocols reduce risk but do not eliminate it. Even well-managed herds can shed pathogens intermittently, and a single contamination event between monthly tests can sicken dozens of consumers.
Legal Status Varies Widely by State
Federal law prohibits the sale of unpasteurized milk across state lines. Within states, the rules are all over the map. Some states allow raw milk to be sold in retail stores. Others permit sales only at the farm where the milk was produced. Some ban all direct sales to consumers.
An increasing number of states have carved out a workaround through “herdshare” or “cowshare” arrangements. In these programs, you purchase a share of ownership in a cow or herd, and in return you receive a portion of the milk it produces. Because you technically own the animal, you are not buying milk in the legal sense, which sidesteps retail sale prohibitions. The legality and regulation of these arrangements varies by state, and the level of oversight ranges from rigorous to essentially nonexistent.
If you’re considering raw milk, checking your state’s specific laws is a practical first step. The CDC maintains a map of state-by-state regulations that is updated periodically.