The majority of cheese eaten and sold is pasteurized, meaning the milk is treated to kill off all bacteria -- some healthy, some not -- before the cheese is made. Raw milk cheeses are made from unpasteurized milk and, according to some, are the tastiest cheese you can find. But the U.S. Food and Drug Administration states that unpasteurized soft cheeses and milk are considered unsafe for consumption. That said, you can legally buy some raw milk cheeses so long as they have been aged for at least 60 days.
The most common type of cheese in markets and grocery stores, pasteurized cheese can be industrially made as well as artisanal. Pasteurized cheese is made from milk that has been heated to 140 or 150 degrees Fahrenheit for a minimum of 30 minutes, before the temperature is lowered, but no less than 55 degrees. Both hard and soft varieties are considered safe for regular consumption, according to the FDA.
Raw Milk Cheeses
Raw milk cheeses, because of their unpasteurized milk content -- from either goats, cows or sheep -- have more flavor and complexity than their pasteurized counterparts. While still new in the United States, raw milk cheeses are part of a traditional diet in large parts of Europe and are made on a small scale in the United States by artisanal cheese makers. A large number of raw milk cheeses are imported.
Dangers of Bacterial Infection
Pasteurization kills off all of the bacteria found in milk, making a pathogen-free cheese. Nonpathogen organisms are still present, which can cause the cheese to spoil if it is not properly stored in a fridge. Listeria, salmonella and E. coli are all potential pathogens that are more likely to be found in raw milk cheeses rather than pasteurized cheeses. Raw milk cheeses are made by small-scale producers, who often put their products under stringent testing to ensure there is no contamination from harmful bacteria, such as E. coli, yeast or coliform bacteria. According to a 2009 issue of "Foodborne Pathogens and Disease," however, there is little scientific study to support the safety of raw milk in general. Learning about independent producers' safety measures may help prevent possible infection from contaminated raw milk.
Other Things to Consider
While raw milk cheeses may contain bacteria in the milk, supporters of raw milk products argue that pasteurized cheese also carries a risk of danger from pathogens. Poor handling and storage of pasteurized milk and cheese can lead to exposure to harmful pathogens, as well as potential cross-contamination. For pregnant women, people with compromised immune systems and children, the FDA does not recommend any consumption of raw milk cheeses. Pregnant women are particularly in danger if they are infected with Listeria, a bacteria that can cause miscarriages, as well as death or illness for newborns.