Every Sunday after Church, I head to our local grocery store with my weekly shopping list. Some weeks I’m more prepared then others but one thing that is always on my list is milk. I have mentioned in previous posts that grocery shopping should not be stressful; however, with all the food labels out there, how can it not be? Choices are great and signs of a healthy market, but I don’t believe that being overwhelmed should be one of the side effects. You might have noticed that on milk labeling that certain containers of cows’ milk have a longer shelf life? How does this milk not spoil?
The quick answer has to do with two different pasteurization techniques.
The milk either undergoes high-temperature, short-time, (HTST) pasteurization or ultra-high temperature pasteurization (UHT) for a longer term shelf life. Before I describe the two most common pasteurization methods, let me briefly explain the pasteurization process.
Pasteurization is an important process that ensures that milk and dairy products are safe for everyone to consume. According to the Grade “A” Pasteurized Milk Ordinance,¹ pasteurization is the process used to kill bacteria without affecting the taste or nutritional value of milk. The Ordinance defines pasteurization as heating every particle of raw milk or milk product, in properly designed and operated equipment, to a certain temperature for a specific period of time.¹ The dairy industry, the Center for Disease Control along with the Food and Drug Administration (FDA) along with many other health and scientific organizations strongly support the pasteurization of milk. You can read the FDA’s position statement here.
What are the differences between HTST and UHT then?
- High temperature, short time (HTST) pasteurization – or traditional pasteurization:
- Heats the milk to a required minimum temperature of 72◦C (161◦F) for at least 15 seconds.¹
- Removes 99.9% of the bacteria in the milk.
- On average, dairy processors recommend HTST milk be consumed eighteen (18) days from the date it is bottled.
A few of the products that undergo high temperature, short time or HTST pasteurization.
- Ultra high temperature pasteurization (UHT) or ultra-pasteurization (UP):
- The milk has to be thermally processed at or above 138◦C (280◦F) for at least two seconds.¹
- The process eliminates a larger percentage of bacteria than HTST pasteurization.
- On average, dairy processors recommend UHT milk be consumed sixty (60) days from the date it is bottled.
Milk that undergoes UHT pasteurization clearly identifies this on the product’s package.
How does organic milk stay fresh for so long? The shelf life for organic milk actually has nothing to do with the milk being organic. The extended shelf life (seen in both organic and conventional milk) is because of the pasteurization process. Organic products are not as commonly produced and so they often have to travel further to reach store shelves. All milk and dairy products (regardless if it is conventional or organic) are antibiotic free and I have posts dedicated to just this topic, click here to read more or here.
At our house, we don’t have any problem going through 2 gallons weekly but if you are looking for milk with a longer shelf life, I would highly recommend you buy UHT milk.
We are proud to be in the dairy industry for many reasons. It not only takes food safety very seriously but it also supports consumer choice.
The bottom line though is that carton to carton, bottle to bottle, all milk is wholesome, safe, and nutritious.
~Mary
Reference
- U.S. Department of Health and Human Services, Public Health Service, Food and Drug Administration. Grade “A” Pasteurized Milk Ordinance…2009 Revision. Washington, D.C.: USDHHS, PHS, FSA. May 15, 2002. http://1.usa.gov/1GGb6yS Accessed April 29, 2015.
Thanks, for your clear explanation. I remember as a girl my Uncle’s farm had lights along a tube that carried milk to a room with a big tank. He said the pasteurization occurred in the area with the lights that indicated things were going well. Don’t know if that is a standard set up these days or not. We use to enjoy his families North Carolina dairy farm so much.
My daughter lives alone in NYC working as a midwife. She told me she didn’t buy milk because it always went bad. She carries her groceries up two stories. So I told her to look for the ultra pasteurized milk for a longer shelf life and told her that Organic milk was almost always Ultra pasteurized. I always buy half and half that is ultra pasteurized. It’s so nice to be able to buy a larger carton than I use to. Now I have enough for any recipe I decide to use at the spur of a moment.