UHT, ultra heat treated or long-life milk has been ultra-pasteurized by being heated in a sealed container to 138C for a few seconds. It is packaged in sealed cartons and can be stored without refrigeration for up to three months. The ultra-pasteurization affects the taste, making it less appealing to drink. It is probably best used for cooking, where it will behave just like ordinary milk. Once it is open, UHT milk must be kept in the refrigerator like fresh milk.
** Asian Recipes