If you or your family are milk drinkers, you probably buy pasteurized milk most of the time, instead of raw milk. Pasteurized milk has undergone the process of pasteurization. Raw milk, on the other hand, is neither pasteurized nor homogenized milk.
Pasteurization involves the manipulation of temperature in order to make milk safe for consumption while avoiding curdling and altering its flavor. It was developed by Louis Pasteur, the namesake of the process, and Claude Bernard on April 20, 1864.
1. High temperature/short time (HTST) – HTST pasteurized milk is subjected to a temperature of 71.7 degrees C (161 degrees F) for 15 to 30 seconds before it is rapidly cooled and packaged. If you buy milk with the “pasteurized” label, it most likely underwent the HTST method. Typically, milk processed with the HTST method can last for 2 to 3 weeks.
2. Extended shelf life (ESL) – ESL pasteurized milk is subjected to a lower temperature, but filtered for removal of microorganisms.
3. Ultrahigh temperature (UHT) – UHT pasteurized milk is subjected to a temperature as high as 138 degrees C (250 degrees F) for a split second. If the milk label is “ultrapasteurized,” it underwent the UHT method. Milk processed with the UHT method, when kept in sterile containers, can last up to 3 months.
4. Batch pasteurized milk – This is milk subjected to relatively low temperatures lasting about 30 minutes before it is cooled.
Contrary to common perception, pasteurization is not able to remove all of the microorganisms or pathogens present in raw milk. However, it does help to reduce the number of pathogens that can cause diseases. For instance, the HTST method aims to kill as much as 99.999% of the viable pathogens in milk. Most yeasts, molds and bacteria that cause spoilage can be killed with HTST.
By drinking pasteurized milk, you are able to avoid typhoid fever, scarlet fever, salmonellosis, diphtheria, listeriosis and brucellosis. Unfortunately, there are also heat-resistant organisms such as mycobacterium tuberculosis, the causative agent of tuberculosis, and coxiella burnetii, the causative agent of Q fever. Therefore, pasteurization is not a guaranteed method.
Raw milk has a longer history than pasteurized milk. Prior to 1864, milk was consumed raw directly after milking animals such as cows, goats and buffaloes. Raw milk is still consumed in many parts of Europe, Asia and Africa, although some countries have placed restrictions or even banned raw milk in the market. Raw milk has enzymes that help assimilate nutrients found in milk. It is creamier than pasteurized milk, so it tastes better.
The Milk Debate
The debate on pasteurized milk versus raw milk has been going on for some time. Milk nutrients are damaged and good bacteria are killed by the pasteurization process. However, regulatory agencies like the US Food and Drug Administration retain the stand that pasteurization protects the health of consumers. This is probably the reason why pasteurized milk is still more popular and widely available, whereas raw milk is rarely encountered. When considering whether to consume pasteurized milk or raw milk, try to balance their advantages and disadvantages.