Shelf-stable (aseptic) milk doesnt need to be kept refrigerated. As long as it's stored between 33 and 75 degrees Fahrenheit, it will be ready whenever you want it. What makes aseptic milk shelf-stable is a unique combination of UHT ultra-pasteurization and shelf-stable packaging. Together, they eliminate the need for refrigeration and prevent spoilage without the need for preservatives. This gives the milk an amazing shelf-life of 6 to 9 months. Refrigeration optional!