Fresh mozzarella, being a soft cheese, often causes confusion for pregnant individuals navigating dietary restrictions. While soft cheeses are generally flagged as risky, the definitive safety guidelines are much more specific than simply avoiding all soft cheeses. This article clarifies the rules for enjoying fresh mozzarella while prioritizing the health and safety of both mother and baby.
The Critical Safety Factor: Pasteurization
The single most important factor determining the safety of any soft cheese during pregnancy, including fresh mozzarella, is whether the milk used has been pasteurized. Pasteurization is a heat treatment process that involves rapidly heating milk to a specific temperature for a set period of time. This thermal processing is highly effective at destroying harmful microorganisms, such as bacteria and fungi, without significantly altering the milk’s nutritional value. This process is specifically designed to eliminate pathogens like Listeria monocytogenes, which can contaminate raw milk. Therefore, confirming the pasteurization status is the primary step in mitigating foodborne risk when selecting cheese.
Specific Guidance for Fresh Mozzarella
The vast majority of fresh mozzarella found in commercial grocery stores in the United States is made with pasteurized milk and is safe to consume. This includes water-packed balls, vacuum-sealed logs, and pre-sliced fresh mozzarella. Checking the product label is the definitive way to confirm safety, as all commercially packaged dairy products are required to list the ingredients and processing method.
Caution is necessary with fresh mozzarella purchased from artisanal cheesemakers, small-scale producers, or farmers’ markets, where the use of unpasteurized milk is more common. If the label does not explicitly state the cheese was made with pasteurized milk, or if the production status is unknown, it should be avoided.
Harder, low-moisture forms of mozzarella, such as the shredded or block varieties typically used for cooking, are also considered safe due to both the pasteurization of the milk and their lower water content, which makes them less hospitable to bacterial growth.
Why Listeria is a Concern During Pregnancy
The strict dietary advice surrounding soft cheeses exists because of the danger posed by the bacterium Listeria monocytogenes, which causes the infection known as listeriosis. Pregnant individuals are at a significantly higher risk of contracting listeriosis, estimated to be between 10 to 18 times more susceptible than the general healthy adult population. This heightened vulnerability is primarily due to the natural suppression of the cell-mediated immune system that occurs during pregnancy. For the mother, listeriosis often presents with mild, non-specific symptoms that can easily be mistaken for a common flu, such as fever, muscle aches, and headache. However, the consequences for the developing fetus can be severe because the bacteria can cross the placental barrier. Fetal infection carries a high risk of complications, including miscarriage, stillbirth, preterm delivery, or severe neonatal illness. This disproportionate and devastating effect on the pregnancy is the reason why health guidelines are so stringent.
Safe Storage and Consumption Practices
Beyond the initial purchase decision, proper handling and consumption practices further reduce any remaining risk associated with fresh mozzarella. All soft cheeses, even those made with pasteurized milk, must be stored correctly in a refrigerator maintained at or below 40°F (4°C) to inhibit bacterial proliferation. Because Listeria can multiply even at refrigeration temperatures, fresh mozzarella should be consumed well within the expiration date and ideally within a few days of opening. It is prudent to avoid fresh mozzarella that is sold in open containers, such as at a deli counter or salad bar, because of the elevated risk of cross-contamination from other foods or shared utensils. Heating the mozzarella until it is steaming hot, such as when baking it on a pizza or incorporating it into a hot pasta dish, effectively kills any potential Listeria bacteria present.