38% less fat than whole milk. Vitamin A & D. Grade A UHT. Real. What is UHT milk? UHT shelf-stable milk is 100% real cow’s milk that is ultra pasteurized and packaged in the Tetra Pak container designed to keep the milk pure and safe. The Tetra Pak container protects the milk from any external contamination. This is made possible thanks to its innovative six layered, airtight sealed package. The result is a wholesome milk that can last at room temperature up to six months. Once opened, it has to be refrigerated and consumed within 7 days.