Pasteurization and Ultra-Pasteurization are heat processes that are designed to kill bacteria (germs) in milk that may be harmful and/or may cause spoilage of milk products. These bacteria are sometimes found in raw milk from the farm, which is why drinking raw milk is not recommended. Milk from farms is transported to dairy processing plants and is generally heat processed within a few days after milking to prevent spoilage and to prolong its shelf-life. “Shelf-life” can be defined as the length of time that a food can be held under recommended or practical storage conditions and still maintain its “freshness” or acceptable quality. The anticipated shelf-life of milk is reflected in its “sell-by” or “code-date,” while many products remain fresh for a period after this date (2-5 days). Both Pasteurized and UltraPasteurized milks should be held under refrigeration at all times. The major differences between Pasteurized and Ultra-Pasteurized milks are the intensity of the heat treatment and the method of packaging, both of which influence the anticipated shelf-life and sell-by dates.