The Most Common Questions about Milk Pasteurization Answered
Pasteurized milk or raw milk? Proponents for milk pasteurization argue that the process slows the growth of dangerous bacteria to prevent contamination and keep people safe, while those in favor of raw milk are suspicious of the pasteurization process and claim that it kills important nutrients we need.
With so many myths and theories floating around out there, what’s actually true about milk pasteurization? Here are some frequently asked questions about the pasteurization process and milk production.
1. When Was Pasteurization Invented?
Pasteurization was invented in 1864 as the solution of a problem with wine going bad during the fermentation process. France was facing this problem until the 1800s, and no one knew why – until Louis Pasteur. He found that the reason wine was spoiling and having a nasty, sour taste was because microorganisms were converting the alcohol content into acetic acid. Pasteur found that by slowly heating and rapidly cooling the liquids, he could kill off the germs to prevent contamination; a process that was eventually named pasteurization.
By the late 1880s, the pasteurization process was used to fight off pathogens in milk that caused tuberculosis. Since then, pasteurization has been refined and adopted worldwide, saving millions of lives by helping to prevent diseases like tuberculosis, diphtheria, and scarlet fever.
2. Why Does Milk Need to be Pasteurized?
Although milk offers important nutrients like calcium, vitamin A, phosphorous, and vitamin B12, raw milk also contains bacteria like Salmonella and E. coli, which can cause life-threatening illnesses. In fact, the Center for Disease Control and Prevention (CDC) announced that over 1500 U.S. citizens between 1993 and 2006 became sick from raw milk. This number could have been significantly higher without the pasteurization process, as raw milk is 150 times more likely to cause illness than pasteurized milk.
3. How Does Pasteurization Work?
Pasteurization is the process of heating milk until dangerous microorganisms are killed off. Today, there are two types of pasteurization that are commonly used in the processing phase:
- Vat Pasteurization: Also known as batch pasteurization, this process heats every particle of milk in a proper pasteurizer at 145°F (63°C) for 30 minutes. When using this holding method, a balance of heating and agitation is used to get proper texture and consistency in the milk.
- High Temperature Short Time Pasteurization (HTST): Also known as flash pasteurization, this is the most common method used today because it is the most efficient and effective way to get rid of microorganisms in the milk. Using stainless steel plates, the liquid is heated to at least 161° F (72° C) for 15 seconds, then quickly cooled.
4. Does Pasteurization Destroy Important Nutrients?
The U.S. Food and Drug Administration does say that the heating involved in pasteurization may affect nutrients, but not significantly enough to the point where it would impact people’s health. In short, pasteurized milk is just as nutrient-rich as raw milk.
5. Can Bacteria Survive Milk Pasteurization?
While pasteurization takes care of most bacteria found in raw milk, researchers have found a set of microorganisms that can actually survive the pasteurization process. This type of bacteria is called thermoduric bacteria, which can survive the heating used in pasteurization.
Unlike most pathogens found naturally in raw milk, thermoduric bacteria are usually found in milk as a result of contamination during the milk production process. Other factors like animal drug residues and pesticides are also potential chemical hazards that can affect the safety of milk.
Luckily, following preventative programs, government regulations, and sanitation procedures, and using high quality processing equipment can help prevent milk contamination outbreaks caused by thermoduric bacteria and other chemical risks.
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