Better Homes and Gardens

Just What Is Shelf-Stable Milk and Why Doesn’t It Need Refrigeration?

Unopened boxes last WAY longer without refrigeration, here’s how.

By Kristy Alpert 

I first discovered shelf-stable milk while living in Europe, where it was the only option available in many grocery stores and markets near my village. The thin boxes were stacked perfectly near containers of cereals and bags of muesli. I never questioned what it meant for cow’s milk to be shelf-stable for two reasons: 1) I was still learning German and “what’s in shelf-stable milk” was far beyond my level 1 German-speaking abilities, 2) I knew Europeans sold eggs at room temperature as well, so I figured there must have been something they had figured out, so I just went along with the process. It wasn’t until I moved back to America and began seeing these familiar boxes in the tea and coffee aisle of my grocery store that I started getting curious. After conducting taste tests at home with my husband—where we agreed that shelf-stable tasted just as good as traditional milk—I reached out to the experts at Maple Hill Creamery to find out what exactly is shelf-stable milk. 

person holding box of shelf stable milk at checkout


What Is Shelf-Stable Milk? 

Shelf-stable (aseptic) milk is milk that does not need to be refrigerated and can be stored at room temperature in your pantry for later use, says Julia Joseph, co-founder of Maple Hill Creamery. Maple Hill’s single-serve, shelf-stable milk boxes ($28 for 12, Amazon) are a true innovation as they provide the only 100% grass-fed organic milk in a shelf-stable format. 

Why Doesn’t Shelf-Stable Milk Need Refrigeration? 

Pasteurization and sterile packaging allow for the shelf-stable storage of milk. Maple Hill Creamery uses ultra-high temperature pasteurization (UHT) combined with a sterile packaging process that allows for shelf stability, Joseph explains.

To process shelf-stable milk, two steps must happen concurrently. Joesph explains the process like this: The first step is ultra-high temperature pasteurization, which refers to the processing temperature. Milk is pasteurized between 280°F to 302°F for two to six seconds. The next step is the pasteurized milk traveling to the sterile containers located in a sterile packaging environment. This enclosed sterile system allows for the sterile packaging to be formed, filled, and sealed to ensure no bacterial or pathogens can be introduced to contaminate the milk. 

How Long Does Shelf-Stable Milk Last? 

The shelf life of shelf-stable milk varies by product and package, says Joseph. Maple Hill Creamery guarantees that its shelf-stable milk will last for 50 days if stored at a room temperature of 75°F. Organic Valley’s site states shelf-stable milk can last six to nine months (that’s about 270 days). Once open, shelf-stable milk should be stored in the refrigerator and is best for five to seven days after opening.

Is Shelf-Stable Milk Safe? 

Shelf-stable milk is absolutely safe for all ages, says Joseph. Because we follow the strict safety protocols through pasteurization and the processing of milk in a sterile environment, drinking shelf-stable milk is just as safe as drinking milk from the refrigerator. In fact, Maple Hill Creamery’s shelf-stable milk is made with the same milk found in their half-gallon refrigerated milk. Many customers prefer to refrigerate shelf-stable milk before drinking it because it is the way they are used to drinking milk, but refrigeration is not required, explains Joseph.

Can You Freeze Shelf-Stable Milk? 

Joseph does not recommend freezing their shelf-stable milk. Once the shelf-stable milk is frozen, it will begin to deteriorate and separate into components, such as water and fat.

Related: Can You Freeze Milk? Here Are Our Test Kitchen’s Tips

Most shelf-stable milk products come in smaller or single-serve containers making them an especially good option for households that don’t consume a lot of milk to reduce their food waste. Single-serve containers are also a great option for camping, hiking, and other times when you won’t have access to a refrigerator. Check out all the shelf-stable milk options online and next time you’re at the grocery store to see if there’s a good option for you.