What Happens if You Don't Boil Milk Before Drinking?

November 26, 2025 •

4 min read

According to the Centers for Disease Control and Prevention (CDC), drinking raw, unpasteurized milk was linked to 202 disease outbreaks between 1998 and 2018, resulting in 2,645 illnesses. So, what happens if you don't boil milk before drinking? The outcome largely depends on whether the milk is raw or has already undergone pasteurization, with serious health risks tied to the consumption of raw milk.

Quick Summary

This article explains the critical difference between raw and pasteurized milk and the health risks of consuming raw milk without boiling. It details common pathogens found in unboiled raw milk, such as E. coli and Salmonella, and the severe symptoms they can cause. It also clarifies why boiling is generally unnecessary for commercially packaged, pasteurized milk.

Key Points

Raw Milk Risks: Drinking unboiled raw milk carries a high risk of contracting dangerous foodborne illnesses from bacteria such as E. coli, Salmonella, and Listeria.
Pasteurization Process: Most commercially available milk is pasteurized, a heating process that eliminates harmful bacteria, making it safe to drink without boiling.
Vulnerable Populations: Infants, children, pregnant women, the elderly, and immunocompromised individuals face a much higher risk of severe illness from consuming raw milk.
Boiling Effects: Boiling raw milk is essential to kill pathogens, but re-boiling pasteurized milk is unnecessary and can reduce its nutritional value.
Read the Label: Always check milk cartons for the word "pasteurized" to ensure its safety for direct consumption.
Home Treatment: For those with access to raw milk, home pasteurization by heating to 145°F for 30 minutes is a recommended safety measure.

The Crucial Difference: Raw vs. Pasteurized Milk

The most important factor in determining the safety of unboiled milk is its origin and treatment. Understanding the difference between raw and pasteurized milk is fundamental to protecting your health.

Raw Milk

Raw milk is milk that comes directly from a cow, goat, or other animal and has not been pasteurized to kill harmful germs. Even if the animal appears healthy and the milking process is clean, raw milk can harbor dangerous pathogens that pose serious health risks. These bacteria can enter the milk during the milking process, from the animal's hide, or through an infected udder. There is no reliable way to tell if raw milk is contaminated just by looking, smelling, or tasting it.

Pasteurized Milk

Pasteurization is a process developed in the 19th century by Louis Pasteur to kill disease-causing microbes. It involves heating milk to a specific temperature for a set period of time—for example, 72°C for 15 seconds—before rapidly cooling it. The overwhelming majority of milk sold in stores and supermarkets has been pasteurized and is clearly labeled as such. This process makes the milk safe to drink directly from the package, as the pathogens have already been eliminated. Re-boiling pasteurized milk is not necessary for safety and can reduce its nutritional value.

Serious Risks of Drinking Unboiled Raw Milk

Consuming raw milk without boiling exposes you to a host of dangerous bacteria that can cause serious foodborne illnesses. Vulnerable populations, including young children, pregnant women, the elderly, and those with weakened immune systems, are at an especially high risk.

Common Pathogens in Raw Milk

Raw milk can be contaminated with several types of harmful bacteria:

E. coli: Certain strains can cause severe stomach cramps, bloody diarrhea, and vomiting. Some cases can lead to life-threatening hemolytic uremic syndrome (HUS), which causes kidney failure.
Salmonella: This can cause fever, abdominal cramps, and diarrhea, and in severe cases, requires hospitalization.
Listeria: Poses a significant threat to pregnant women, as it can cause miscarriage, stillbirth, or life-threatening infections in newborns. Symptoms often include fever, muscle aches, nausea, and diarrhea.
Campylobacter: Can cause diarrhea, cramps, abdominal pain, and fever.
Brucella and Mycobacterium bovis: These can cause chronic diseases like brucellosis and tuberculosis.

Health Consequences

The immediate consequences of drinking contaminated raw milk can range from uncomfortable gastrointestinal issues to severe, debilitating, and even fatal conditions. Vomiting, diarrhea, and stomach pain are the most common symptoms. More severe outcomes can include kidney failure, paralysis, and chronic disorders.

Comparison of Unboiled Raw vs. Pasteurized Milk


Feature	Unboiled Raw Milk	Unboiled Pasteurized Milk
Safety	High risk of carrying dangerous bacteria (e.g., E. coli, Salmonella, Listeria).	Very low risk of bacterial contamination; already heat-treated for safety.
Bacterial Content	Can contain harmful pathogens and spoilage-causing bacteria.	Pathogens are eliminated during pasteurization.
Nutritional Value	Advocates claim it retains more enzymes and probiotics, but scientific evidence is lacking and boiling can also affect nutrients.	Most nutrients are retained; minimal effect on vitamins A, D, and calcium.
Taste	Flavor profile can vary based on the animal, feed, and farm conditions.	Consistent, mild flavor profile.
Risk Group	Extremely dangerous for high-risk groups including children, pregnant women, and the elderly.	Safe for all consumers, including vulnerable populations.
Consumption	Must be boiled before drinking to kill pathogens and ensure safety.	Can be consumed directly from the carton, as it is already safe.

What to Do If You Drink Unboiled Raw Milk

If you have knowingly consumed raw, unboiled milk and begin to experience symptoms like diarrhea, vomiting, or flu-like symptoms, it is crucial to seek medical attention, especially if you fall into a high-risk category. A doctor can help determine the cause of your illness and provide appropriate treatment. For those handling raw milk at home, proper home pasteurization is recommended. This typically involves heating the milk to a specified temperature, such as 145°F for 30 minutes, to ensure it is safe to drink.

What to Do If You Don't Boil Pasteurized Milk

As established, it is entirely safe to drink pasteurized milk directly from the carton without any boiling, as the pasteurization process has already eliminated harmful bacteria. In fact, re-boiling pasteurized milk offers no additional safety benefits and can diminish its nutritional content, particularly heat-sensitive vitamins like B12.

Conclusion

What happens if you don't boil milk before drinking is contingent on the type of milk. If it is raw milk, skipping the boiling process can lead to serious and potentially life-threatening foodborne illnesses from bacteria like E. coli and Salmonella. However, if the milk is commercially pasteurized, not boiling it is completely safe, as the heat treatment process has already been completed. Always check the label and prioritize safety by consuming pasteurized milk or properly boiling any raw milk before drinking. Making an informed choice is the best way to enjoy milk's nutritional benefits without the associated health risks. For more in-depth information, you can consult reliable sources like the FDA's page on raw milk safety.

Frequently Asked Questions

Yes, absolutely. Pasteurized milk has already been heated to kill harmful bacteria, making it safe for direct consumption without any need for further boiling.

Raw milk can contain a variety of dangerous bacteria, including E. coli, Salmonella, Campylobacter, Listeria, and Brucella, which can cause severe illness.

Symptoms of foodborne illness from raw milk include vomiting, diarrhea, abdominal pain, fever, and flu-like symptoms. In severe cases, it can lead to more serious conditions like kidney failure.

Boiling can slightly reduce the levels of some heat-sensitive vitamins, particularly B vitamins and Vitamin C, but the effect on overall nutritional value is minimal.

No, it is not safe. Pregnant women are at a higher risk of listeriosis, a severe infection from raw milk that can lead to miscarriage or stillbirth.

While proper hygiene can reduce the risk of contamination, it cannot eliminate it completely. Harmful bacteria can still enter the milk from the animal itself or the environment, even in sanitary conditions.

Pasteurization is a precise process of heating milk to a specific temperature for a set time (e.g., 72°C for 15 seconds) to kill pathogens. Boiling is simply heating milk to its boiling point (around 100°C), which is a less controlled method.