Raw milk cheese, often referred to as unpasteurized cheese, is a product made from milk that has not undergone the heat treatment known as pasteurization. This process, developed in the 19th century, involves heating milk to a specific temperature for a set period to eliminate harmful bacteria. When cheesemakers skip this step, they preserve the milk’s natural microflora, which can contribute unique characteristics to the final product. The decision to use raw milk is a balance between preserving traditional flavor profiles and adhering to modern food safety standards. This article explores the definition of raw milk cheese, the regulations governing its sale, and the trade-offs between flavor and safety.
Defining Raw Milk Cheese
Raw milk cheese is defined as cheese made from milk that has not been heated above 104°F (40°C) during production. Standard pasteurization, such as the High-Temperature Short-Time (HTST) method, heats milk to at least 161°F (72°C) for 15 seconds to destroy nearly all viable microorganisms. The primary purpose of this heat treatment is to eliminate pathogens like Listeria, E. coli, and Salmonella that can be present in raw milk.
Cheesemakers who choose to use raw milk do so to retain the milk’s native bacterial cultures and enzymes. These natural components are believed to be responsible for developing complex, nuanced flavors often lost during the high heat of pasteurization. The resulting cheese is thought to better express the terroir, or the environmental factors of the farm, including the animal’s diet and the local microclimate. While some cheesemakers use a process called thermization, which heats milk to a lower temperature (around 135°F to 154°F) for a short time, this milk is still considered unpasteurized for regulatory purposes.
The 60-Day Aging Rule
The sale of raw milk cheese in the United States is governed by a specific regulation from the Food and Drug Administration (FDA). This rule, in place since 1949, mandates that any cheese made from unpasteurized milk must be aged for a minimum of 60 days before it can be sold to consumers. The cheese must also be cured at a temperature of no less than 35°F (1.7°C) throughout this period.
The rationale behind the 60-day requirement is that the cheese’s natural conditions—specifically its acidity, salt content, and low moisture—will reduce harmful bacteria over time. This process was initially based on research concerning pathogen survival in hard cheeses like Cheddar. However, modern studies show that some strains of E. coli can survive past the 60-day mark in certain cheese types, leading to debate about the rule’s effectiveness. The regulation effectively prohibits the sale of soft, fresh, or bloomy-rind raw milk cheeses, such as traditional Camembert or Brie, in the U.S.
Common Raw Milk Cheeses
Many of the world’s most celebrated cheeses are traditionally made with raw milk, though pasteurized versions are widely available. Parmigiano-Reggiano, the hard Italian cheese, is almost always made with raw milk and aged for a minimum of 12 months. Similarly, the French blue cheese Roquefort, made from sheep’s milk, is protected by a designation requiring the use of unpasteurized milk.
Other European classics frequently made with raw milk include Gruyère AOP from Switzerland and Comté from France. Certain artisanal cheddars, particularly those made in the traditional cloth-bound style, are also often produced using unpasteurized milk. Consumers must check the label for the words “raw milk” or “unpasteurized,” as many domestic and imported versions use pasteurized milk for consistency.
Safety and Flavor Trade-Offs
The choice between raw and pasteurized cheese involves a trade-off between flavor complexity and food safety assurance. Raw milk cheeses are valued by connoisseurs for their depth of flavor, which is attributed to the diverse microbial ecosystem preserved by avoiding heat treatment. This natural microflora contributes to a complex flavor profile that reflects the unique environment of the dairy farm.
However, the absence of pasteurization means there is a potential risk of foodborne illness from pathogens that may be present in the milk. Health authorities advise that certain vulnerable populations should exercise caution and avoid raw milk cheeses entirely. This precautionary group includes pregnant women, young children, the elderly, and individuals with compromised immune systems. For the general population, the risk is low, but consumers should purchase raw milk cheeses from reputable sources.