Developed in 1864 by French chemist Louis Pasteur, pasteurization kills organisms — such as salmonella, listeria, and brucella — that can make you sick or cause food to spoil. Although the FDA claims the effects on nutrients are negligible, opponents argue that pasteurization changes foods' flavor and damages beneficial vitamins and minerals. Here are the types of pasteurization used today.

Ultra-high temperature (UHT) Milk, fruit juice, dairy creamer, cheese sauce, yogurt, wine with less than 14 percent alcohol content Product is heated to at least 280° for 1-2 seconds; most common in countries where many residents don't own refrigerators Cost effective; minimal changes in color, flavor, and texture; extends shelf life by months Milk can taste cooked
High temperature short time (HTST) / flash Milk, most juice, beer, almonds Food is heated to 160° for 15 seconds and then rapidly cooled to 40°; most frequently used for U.S. milk Juices can have shelf lives of up to a year Products require refrigeration; opponents say pasteurizing almonds kills the nut's ability to sprout
Vat Most American-made hard and soft cheese, yogurt, buttermilk Louis Pasteur's original method heats product to 145° in a large vat for 30 minutes Milk retains flavor This method is semi-obsolete because of time intensiveness and higher cost
Unpasteurized/raw Dairy Dairy is not pasteurized before consumption Creamier; advocates claim it';s tastier and more nutritious Raw products spoil quicker; can contain pathogens such as E. coli ; are illegal to sell in most states; and require refrigeration
Irradiation Meat, wheat, some fruits and vegetables, spices Foods are exposed to small amounts of gamma rays Kills insects and pathogens, prevents sprouting, extends shelf life There's no proof that irradiated foods are safe for human consumption; surviving organisms could help create pathogenic superstrains