A thermal process used to extend the shelf-life of foods such as fruit juices, beer, milk, and other dairy products by destroying or inactivating harmful and pathogenic microorganisms that might be potentially present. Pasteurization is usually achieved at a specified temperature and time combination. For example, milk can be pasteurized by heating to 72^ºC and holding the temperature for 15 seconds. There are other temperature-time combinations that will achieve the same effect such as the Holder process, which involves heating between 63^ºC to 66^ºC and holding for 30 minutes. The rapid heating and cooling can be achieved using plate heat exchangers. The process is named after French chemist and biologist Louis Pasteur (1822–95).