Feta cheese is a soft, white, brined cheese traditionally made in Greece from sheep’s milk, or a mixture of sheep and goat’s milk. For many pregnant individuals, the safety of soft cheeses like feta is a frequent concern, given general health advisories. Feta can be safely included in a pregnancy diet, but this safety is entirely conditional on how the cheese was produced and handled. The primary distinction rests upon the processing of the milk used to create the cheese.
The Crucial Differentiator: Pasteurization
The question of whether feta is safe hinges on a single manufacturing step called pasteurization. This process involves heating the milk to a specific high temperature for a set amount of time, effectively eliminating harmful bacteria that may be present in the raw product. Unpasteurized, or raw milk, feta carries a significant risk because it has not undergone this heat treatment.
Most commercially available feta cheese in the United States and other developed nations is made with pasteurized milk, making it generally safe for consumption. However, imported varieties, artisanal cheeses, or those purchased from specialty markets may still be made with unpasteurized milk.
To ensure safety, pregnant consumers must always check the product label for the word “pasteurized” or the phrase “made from pasteurized milk.” If the label is unclear, or if you are dining out and cannot confirm the source, it is best to avoid the feta entirely. This simple label check is the most effective way to mitigate the associated risks.
Understanding the Primary Risk: Listeriosis
The reason for avoiding unpasteurized soft cheeses is the potential presence of a bacterium called Listeria monocytogenes. This pathogen causes a serious foodborne illness known as listeriosis. Pregnant individuals are particularly susceptible to this infection, being approximately 10 to 18 times more likely to contract it than the general population due to pregnancy-related changes in the immune system.
While listeriosis in the mother often presents as a mild, flu-like illness, the consequences for the developing fetus can be severe. The bacteria can cross the placenta, leading to devastating outcomes such as miscarriage, stillbirth, premature birth, or severe, life-threatening infection in the newborn.
Unlike most other foodborne bacteria, Listeria is unique because it can survive and even multiply at typical refrigeration temperatures, making soft cheeses a concerning environment for its growth. The incubation period for listeriosis can also be long, sometimes taking up to 70 days after exposure for symptoms to manifest.
Safe Consumption Guidelines
Once a pregnant consumer has confirmed the feta cheese is made with pasteurized milk, safe handling practices are necessary to prevent post-production contamination. Feta should be stored in the refrigerator at or below 40°F (4°C) to slow the potential growth of any lingering bacteria. It is also important to consume the cheese well before the expiration date and within a few days of opening the package.
When preparing food, cross-contamination prevention is an important safety step. Using separate cutting boards and utensils for the feta and other fresh produce helps ensure that bacteria from one source do not transfer to the cheese. Any feta that has been left at room temperature for more than two hours should be discarded, as this allows bacteria to multiply rapidly.
If the pasteurization status of the feta is unknown or if there is any doubt about its safety, the cheese can still be consumed safely by thorough heating. Heating feta until it is steaming hot, reaching an internal temperature of at least 165°F (74°C), will effectively destroy any Listeria bacteria that may be present. This makes heated dishes like baked pasta, casseroles, or pizza topped with feta a safe option, regardless of the milk’s initial processing.