Ultra-high-temperature processing

Ultra-high temperature processing (UHT), ultra-heat treatment, and ultra-pasteurization is a food processing technology that sterilizes a liquid food by heating the food for two to five seconds to a temperature greater than 140 °C (284 °F) to kill bacterial endospores. In the production of food products, UHT processing is applied to milk and milk products, and to the production of fruit juices, soy milk, wine, savoury canned foods, and honey. UHT milk was first developed in the 1960s and became generally available for consumption in the 1970s. The heat used during the UHT process can cause Maillard browning and change the taste and smell of dairy products. An alternative process is flash pasteurization, in which the milk is heated to 72 °C (162 °F) for at least fifteen seconds.

UHT milk packaged in a sterile container has a typical unrefrigerated shelf life of six to nine months. In contrast, flash-pasteurized milk has a shelf life of about two weeks from processing, or about one week from being put on sale.