CurdNerds

Further proof that Listeria outbreaks are not solely a problem of raw dairy products: Swiss-American, Inc., of St. Louis, MO, on Thursday announced a recall of their Cut Cahill's Farm Porter Cheese, a pasteurized cheese made with porter ale. Samples of the cheese were found to contain Listeria monocytogenes, a bacteria that causes gastrointestinal distress in humans. It is generally harmless for most people (except for the diarrhea, nausea and vomiting), but it is especially dangerous for pregnant women where it can cause miscarriages and stillbirths.

L. monocytogenes is usually killed off in the process of pasteurization, and is often cited as one of the reasons why consuming raw dairy is deemed unsafe. However, as in this case, it is still possible for listeria infection to occur in pasteurized dairy products. Raw milk contains many different living organisms, and unless some contamination has occurred, these organisms are beneficial. There are bacteria naturally occurring in raw milk that create an environment generally inhospitable to the bacteria that can make you sick (such as listeria). Pasteurization, unfortunately, kills these beneficial bacteria along with all the potentially harmful ones. The sterile milk that results is a veritable feeding ground for any re-introduced bacteria to grow unabated. Thus, post-pasteurization milk, if handled incorrectly, can actually be more dangerous than raw milk, because it is a ripe environment for harmful bacteria such as listeria. And this is precisely what happened in the case of this recalled cheese.

To be sure, it is important for consumers to be educated about the risks and benefits associated with consuming raw dairy products, but it is also important to recognize that pasteurization is not a cure-all and can actually sometimes make for products that are less safe than their raw counterparts.