A few weeks ago, I was in a grocery store in Tulum, Mexico when I overheard two Americans talking next to one of the coolers containing dairy products.
“I can’t believe they’re out of milk,” one of them said in an annoyed voice.
“I don’t even see a place for it,” his friend added.
Being the helpful person that I am, I told them the milk is commonly sold unrefrigerated in boxes and then I directed them to the correct aisle. I also added that it is good for several months unless it is opened.
Based on their expressions of surprise and disbelief, you would have thought that I had just told them to go milk a cow out back. The funny thing was that after a brief discussion, the two chose NOT to try the boxed milk.
Americans in particular seem to have a hard time wrapping their heads around the concept of milk stored at room temperature. This topic comes up so often that I decided to take a few minutes to dedicate a post to it.
Even American expats who live full or part time in Mexico talk about milk on a regular basis. For many of them it has become a quest to find refrigerated milk with a short shelf life and when they do – they are eager to share the location with their friends.
The Science Behind It
The milk inside the container is the same, the difference is in the pasteurization technique and the packaging.
This is also called shelf safe milk or UHT milk. UHT stands for Ultra High Temperature.
UHT milk is heated to between 275-284 degrees Fahrenheit for only three seconds and is packaged in containers that protect the product from light and air.
Shelf life: Up to 6 months without refrigeration or preservatives (according to Tetra Pak). Once opened, it is recommended to use the milk within 14 days.
Traditional Pasteurized Milk
During the pasteurization process, the milk is only heated to between 161-167 degrees Fahrenheit for 15-20 seconds before it is cooled. The milk has to be stored cool to avoid it spoiling too quickly.
Shelf life: 7-15 days if the milk is stored cold.
Let’s Wrap This Up
Before moving to Mexico, I rarely ever had a conversation about milk. The few times that I did, it usually involved my wife asking me to smell it to see if it was still good. Those were certainly simpler times.
Here in Mexico, the topic of milk comes up quite frequently. In fact, you would think that some people were milk connoisseurs by the way they talk about the subtle taste differences between the two pasteurization methods.
Personally, I don’t notice any difference in the taste. However, the only time that I drink milk is when it’s poured over cereal — so I’m probably not the best judge.