What American doesn’t recognize the tagline “Got Milk?”, a popular advertising campaign launched over 20 years ago in America that, according to research by Jeff Goodby in Adweek, “has become the most remembered tagline in beverage history.” He continues, “It is so ubiquitous, in fact, that people don’t think of it as a tagline anymore. It is a piece of culture.” Considering that milk is a staple item in most households and food industry businesses, milk may be a bigger part of our culture than we give it credit for. Over the years we have seen how the processes of manufacturing and distributing milk have evolved and how that has directly affected the type of milk we consume in different parts of the world.
To give you a quick recap, milk for many years came directly from cattle farms, and then during the Middle Ages we saw the first cooperatives in France. During the Renaissance we had the first hygiene regulation of milk, and later in the late 19th century we finally had sterilized milk. From the 20th to the 21st century we continue to see the effects of different laws and regulations being put on industrial pasteurization. As we continue to improve regulations and conserve the freshness of milk, we see how culture and geography influence the type of pasteurization process that is more popular.
As explained by online milk processing resource, www.milkfacts.info, the purpose of pasteurization is, 1. To increase milk safety for the consumer by destroying disease causing microorganisms (pathogens) that may be present in milk. 2. To increase keeping the quality of milk products by destroying spoilage microorganisms and enzymes that contribute to the reduced quality and shelf life of milk. The variances in these pasteurization processes will always meet the minimum requirements in state or country laws. The main differences you will see between these pasteurization processes will be the processing times, the temperature at which the milk is heated, and packaging.
HTST Milk (High Temperature Short Time Pasteurization)
Here in America, one of the more common forms of pasteurization is HTST or High Temperature Short Time pasteurization. This process kills the germs present in the milk while preserving essential vitamins and nutrients. The milk is heated to 72-74 degrees Celsius (162-165 degrees Fahrenheit) for 15 to 20 seconds in order to kill the Coxiella brunetii, the most heat resistant pathogen in raw milk.
This technique elongates the shelf life without adding any preservatives. After pasteurization, the HTST milk is moved to a cooling section and chilled until it reaches 4 degrees Celsius (39 degrees Fahrenheit). From there it is kept refrigerated during the remainder of its shelf life. HTST milk usually will last anywhere from 16-21 days.
UHT Milk (Ultra High Temperature Pasteurization)
Another very popular type of milk is UHT or Ultra High Temperature pasteurization. UHT pasteurization is the process of heating the milk to between 135-150 degrees Celsius (275-302 degrees Fahrenheit) for 2-3 seconds, chilling it immediately, and aseptically packaging it in an air-tight container for storage.
This process kills all the bacteria present. While all the bad bacteria is killed, unfortunately due to the high temperature during pasteurization, some of the nutrients and vitamins are as well. UHT pasteurization elongates the shelf life to anywhere from 6-9 months (until opened) but does not require refrigeration storage until opened as well.
UHT vs HTST
When you compare the two types of milk, there are many factors that can make one more appealing than the other. It really comes down to the qualities that are most valuable for the end user. Storage and shelf life are among the more drastic differences that we can see between the two. When we look at where the majority of these two types of milk are consumed we see how culture and tradition have a big impact on which milk you choose as well. Americans have traditionally bought and stored milk in a refrigerator. In Europe or South America, for example, where storage spaces are more limited, having milk stored on the shelf is a norm that Americans aren’t used to.
Even though it may seem like something we are not familiar with, according to online nutrition resource www.foodrenegade.com, when UHT milk was first introduced to the U.S. market back in 1993, it was discovered that Americans distrusted milk that hadn’t been refrigerated. The North American market preferred cold milk, and UHT milk doesn’t need to be refrigerated. Inspired by this fact, a milk producer is said to have started selling their UHT milk in normal packaging, in the refrigerator aisle without advertising their pasteurization method. Now, almost all of the organic milk and the majority of conventional milk available in U.S. supermarkets is UHT processed. This example is just to show that we are creatures of habit and it is hard for us to step out of our comfort zones.
While some may argue that aside from storage there is a slight difference in taste and color due to the temperatures at which milk is pasteurized, what it boils down to for most Americans is the prospect of consuming milk that was purchased off the shelf when the majority of the population was raised on milk only from the refrigerated section. The next time you are at the grocery store take a look at the label and see how the milk you are buying is pasteurized, then ask yourself, got UHT or got HTST?