Raw cheese is generally safe for healthy adults when it has been properly aged, but it does carry more risk than pasteurized cheese. In the United States, raw milk cheese must be aged at least 60 days before sale, a rule designed to let time, salt, acidity, and beneficial bacteria reduce harmful pathogens. That said, unpasteurized dairy products cause roughly 840 times more illnesses and 45 times more hospitalizations than their pasteurized counterparts, per CDC data from 2009 to 2014. The risk isn’t equal across all raw cheeses, though. The type of cheese, how it’s made, and who’s eating it all matter.
How the 60-Day Aging Rule Works
The FDA requires that any cheese made from unpasteurized milk be aged for a minimum of 60 days at a temperature no lower than 35°F before it can be sold. During this ripening period, several things happen simultaneously. The cheese loses moisture, which makes it harder for bacteria to survive. Its pH drops as lactic acid bacteria produce acid, creating an environment hostile to pathogens. Salt draws out additional water and further inhibits microbial growth. Beneficial bacteria also compete directly with harmful organisms for nutrients and space.
In aged raw cheddar, for example, pH values typically settle between 4.77 and 5.09, and water activity stays in the 0.95 to 0.98 range. These conditions don’t guarantee pathogen elimination, but they significantly reduce the likelihood of dangerous contamination. The FDA conducts ongoing surveillance sampling of 60-day-aged raw milk cheeses as a preventive measure to catch contaminated products before they reach consumers.
Hard Cheese vs. Soft Cheese: A Major Distinction
Not all raw cheeses carry the same level of risk. Hard, aged varieties like raw-milk cheddar, Parmesan, and Gruyère have had months or even years for moisture to leave the cheese, acidity to build, and beneficial bacteria to crowd out pathogens. These cheeses are considerably safer than soft varieties.
Soft cheeses are high in moisture and often have milder acidity, both of which create a friendlier environment for bacteria like Listeria. The CDC specifically flags queso fresco-type cheeses as a concern because they are fresh, soft, high-moisture, low-acidity products that don’t go through a significant aging process. White cheeses with high water activity and limited starter cultures provide what researchers describe as an ideal environment for the growth of foodborne pathogens. If you’re buying raw cheese and want to minimize risk, hard aged varieties are the safest option.
Which Pathogens Are the Concern
The bacteria most commonly associated with raw milk cheese are Listeria monocytogenes, Salmonella, E. coli O157:H7, and Staphylococcus aureus. These organisms can be present in the udder of healthy dairy animals or transferred from workers’ hands during milking, meaning contamination can happen even in clean operations.
Listeria is the most serious threat. It has a high mortality rate and is particularly dangerous for pregnant women, older adults, and people with weakened immune systems. A European surveillance study found a prevalence rate of 0.9% for Listeria in soft and semisoft cheeses made from raw or low-heat-treated milk. Salmonella remains the leading cause of foodborne outbreaks in the EU, responsible for thousands of hospitalizations annually. Staphylococcus aureus causes food poisoning characterized by nausea, vomiting, and diarrhea when bacterial levels get high enough to produce toxins in the cheese.
In well-made, properly aged raw cheeses, these pathogens are rarely detected. One study of 245 raw milk cheese samples found no Salmonella or Listeria at all, though E. coli appeared in 20 samples and Staphylococcus was present throughout. The quality of the cheesemaking operation matters enormously.
The Numbers on Illness Risk
The clearest picture of comparative risk comes from CDC outbreak data. Unpasteurized milk and cheese are consumed by only about 3.2% and 1.6% of the U.S. population, respectively, yet these products were responsible for 96% of all dairy-related illnesses during the study period. On average, dairy-related outbreaks cause about 760 illnesses and 22 hospitalizations per year in the United States, mostly from Salmonella and Campylobacter.
To put that in perspective for an individual: the absolute number of people sickened each year is relatively small compared to the millions who eat raw cheese without incident. But your per-serving risk is dramatically higher with unpasteurized products than with pasteurized ones. As raw dairy consumption grows in popularity, the CDC projects illnesses will rise proportionally. A doubling in consumption could increase outbreak-related illnesses by 96%.
Who Should Avoid Raw Cheese
Pregnant women are 10 times more likely than the general population to develop a Listeria infection. The CDC recommends they avoid soft cheese made from unpasteurized milk entirely, including brie, camembert, blue-veined varieties, and any queso fresco-type cheese (even when made with pasteurized milk, since the fresh, high-moisture format itself poses risk). Hard cheeses made from pasteurized milk, like cheddar, Parmesan, and Swiss, are considered safer choices during pregnancy.
People with weakened immune systems, whether from chemotherapy, organ transplants, HIV, or chronic illness, face similar elevated risks. Young children and older adults are also more vulnerable to severe outcomes from foodborne infections. For these groups, the small but real risk of raw cheese outweighs the benefits.
Why People Seek Out Raw Cheese
Raw cheese fans aren’t imagining the difference in flavor. Because pasteurization kills native enzymes and much of the natural microbial community in milk, raw cheeses develop more complex taste profiles during aging. Raw milk cheese shows higher rates of both proteolysis (protein breakdown) and lipolysis (fat breakdown) compared to pasteurized versions. These processes generate the free fatty acids and amino acids that give aged cheese its depth and sharpness.
Pasteurization also eliminates populations of Lactobacilli, Enterococci, and yeasts that contribute to flavor development and, in some cases, may function as beneficial bacteria. Raw milk cheese retains these organisms, which is one reason artisanal cheesemakers prize unpasteurized milk. Whether these surviving bacteria provide meaningful probiotic benefits to the person eating the cheese is less clear, but the flavor differences are well documented.
How to Identify Raw Cheese
U.S. labeling rules require that cheese made from unpasteurized milk be identified. Look for terms like “raw milk,” “unpasteurized,” or “heat treated” on the label. If a cheese says “heat treated,” the milk was warmed but not to full pasteurization temperatures, which means it falls into the same category as raw for safety purposes. Imported cheeses, particularly from France, may not always use these exact terms, so checking ingredient lists for “raw milk” or “lait cru” is worth the effort. If the label doesn’t mention pasteurization at all and you’re buying from a farmers’ market or specialty shop, ask the seller directly.