The Facts and Myths of Pasteurized Milk

Do you know how pasteurization was invented? The idea of the process started when innumerable people began to get sick and die due to various diseases transmitted via raw milk. Some of these diseases were tuberculosis, typhoid fever, and scarlet fever. Because of pasteurization, the spread of illness to millions of people was prevented.

Pasteurization is the process of killing harmful bacteria through heating the milk under a fixed temperature for a certain span of time. Some people are convinced that pasteurization can harm milk, leading them to believe that unpasteurized or raw one is a safer and healthier alternative. This is because they were fed with numerous myths on pasteurization which science was able to refute.

But before we go on with these myths, let us first have a brief discussion on the pasteurization process.

An Overview of the Pasteurization Process

There are various types of pasteurization processes, but the commonly used one in dairy industries is vat pasteurization. They use this method to prepare starter culture milk before processing cheese, buttermilk, and yogurt.

Vat pasteurization, or batch pasteurization, is also referred to as the holding method. In this process, the raw milk is heated in a stainless-steel container, called a vat, for 30 minutes. The vat is fitted with the following:

  • Pipes in delivering steam and water towards the jacket liner,
  • Thermometers in monitoring and recording product temperatures, and
  • An agitation method in assuring the uniformity in the distribution of temperature.

The vat pasteurization process includes the following main steps:

  • The product constituents travel over the inlet pipe to the container/vat. The outlet valve (typically a check valve), is closed during this process.
  • The product inside the container jacket is heated by hot water or steam while it is continuously moved by agitators.
  • The product is constrained in the container for 30 minutes. The thermometers track and document the temperature during the whole duration of the process.
  • When the required time is reached, the product which is now pasteurized leaves the container via the outlet check valve.

As vat pasteurization deals with food and beverages, the processing components need to be made from sanitary materials. Not only the pipe and the vat but also the outlet check valve which should be made from stainless steel as it may be directly in contact with the product.

The outlet check valve plays a vital role in the output product as it prevents back-flows to ensure that cleanliness and hygiene are optimized. Pasteurization industries also need to make sure that the valve is leak-proof as this is where the majority of processing problems stem from. This makes finding a reliable valve manufacturer a crucial thing. Visit to learn more about valves for pasteurization processes.

Now, without any further ado, let us proceed to the major myths and facts of pasteurized milk.

Myth #1.  Pasteurization kills all of the nutrients in the milk

Since pasteurization started, this myth was able to persuade a lot of people without any scientific evidence. When the process started to become popular in the early years of the last century, there are some people who do not trust the technology. But succeeding researches on the major nutritional constituents of pasteurized and raw milk had shown no significant differences. Such as carbohydrates, proteins, and vitamins.

It is true that some components of the raw milk are broken down during pasteurization but the actual nutritional effects are marginal. You can check the comparison between the nutritional constituents of pasteurized and raw one based on the container labels of each product here.

Myth #2.  Raw milk is preferred for babies than pasteurized because it is healthier.

Activists of raw milk in the developed countries, most specifically in the United States, have been preserving this myth. Contradictory, the majority of the parents in developing countries are aware of the hazards of unpasteurized milk. They boil the raw one to kill pathogens before giving them to babies and young children.

Countless studies have shown that the healthiest choice for infants is breastfeeding. The milk of a human mother is formulated with the best sources of nutrition for boosting the immune system of her baby. When a mother’s choice is not breastfeeding, pasteurized one must only be the one given to babies and young children. Public health and medical communities worldwide had agreed to this unanimously.

Myth #3: Pasteurized milk can cause lactose intolerance.

Milk contains lactose which is a natural sugar. Lactose intolerance happens when the gastrointestinal tract lacks an enzyme for easily breaking down lactose present in the milk. Both pasteurized and raw one has lactose and pasteurizing milk does not modify the lactose content. Thus, neither causes lactose intolerance.

Advocates of raw milk argue that it contains beneficial bacteria – Bifidobacterium. This is a probiotic that helps in the digestion of lactose. While this probiotic may be present in raw milk, it is the result of animal fecal contamination. Thus, is not deemed to be beneficial.

Myth #4: Raw milk is a more nutritious option than pasteurized milk.

As mentioned in the first myth, the difference in the nutritional components of raw and pasteurized milk is marginal. The pasteurization process may kill some of the beneficial bacteria along with the harmful bacteria. But the likelihood of developing food-borne illnesses from raw milk outweigh the prospective benefits of the beneficial bacteria found in dairy products like yogurt. This is due to the bacterial pathogens present in the raw milk.

Furthermore, dangerous organisms such as Escherichia coli, Listeria, and Salmonella may thrive in raw milk. This can cause health risks and as you may know, young children are the most vulnerable ones to the possible infections caused by raw milk.

Myth #5: Pasteurized milk causes allergic reactions to milk

The milk proteins causing allergies are found in both pasteurized and raw milk. Thus, pasteurized milk does not initiate new allergies.


Pasteurization is a method of heating raw milk under a pre-set temperature for a specific timeframe to destroy dangerous bacteria present in the raw milk. This has led to many myths, including the belief that raw milk is more nutritious than pasteurized milk and thus is healthier for babies.

However, as science was able to prove, the pasteurization process does not destroy all of the bacteria in raw milk. The difference between the nutritional content in both pasteurized and unpasteurized milk is not significant. So, the effects that may be caused by consuming pasteurized milk and raw milk, especially by infants and young children, do not differ.