Ultra Pasteurized milk does not need to be refrigerated before opening. Does Ultra Pasteurized Milk Need to be Refrigerated? All in all, UP milk is a great way to get the same flavor and texture of traditional milk without all the hassle of refrigerating it. It can be stored at room temperature, so you don’t have to worry about refrigerating it until you open it. UP milk also has a richer, creamier texture, which makes it a great choice for baking and cooking. This means you can buy it in larger quantities and not worry about it going bad too quickly. The most notable is that it has a much longer shelf life, thanks to a special pasteurization process that eliminates most bacteria. Ultra Pasteurized milk, also known as UP milk, offers several benefits over traditional milk. Read on to find out if you do indeed need to refrigerate ultra pasteurized milk, and if so, when. It is important to know whether or not you need to refrigerate ultra pasteurized milk in order to make sure you’re drinking safe and tasty milk. Ultra pasteurized milk is a great alternative to regular, pasteurized milk because it has a longer shelf life and is less likely to spoil or become contaminated.