Ultra high temperature, also known as UHT, in which milk is ultra-pasteurized and packaged in sterilized containers. It’s natural milk, just like you purchase at the dairy store; however, the unique packaging and pasteurization process makes it have a shelf-life of some months. While most milk goes through a standard pasteurization process, UHT milk goes through ultra high temperature pasteurization, which safely heats the milk to a higher-than-usual temperature and kills the milk’s harmful bacteria. It is then packed in sterilized containers, also called aseptic packaging, which keeps the milk fresher for longer.