A process during which a liquid such as milk is rapidly heated almost to the boiling point and is then rapidly cooled.‎ The purpose of this process is to kill the bacteria in the liquid without damaging its taste or nutritional value.‎ ‎The process prolongs the shelf life of the liquid.‎ The process is named after the scientist Louis Pasteur, who invented it.‎ ‎The classic process of pasteurization is: heating to a temperature of 63 degrees celsius for 30 minutes. Another alternative is heating to a temperature of 72 degrees celsius for half a minute.