The appearance of mold on cheese often presents a dilemma: should it be discarded or can the moldy portion be removed? The safety of cutting mold off cheese depends on the cheese type and the nature of the mold. Understanding these distinctions is important for informed food safety decisions.
General Safety Guidelines
For some cheeses, removing mold is safe; for others, discarding the entire product is advisable. The primary factor is the cheese’s texture and moisture content. Hard and semi-hard cheeses resist deep mold penetration due to their dense structure and lower moisture, making surface removal acceptable. Conversely, mold on soft, crumbled, or sliced cheeses indicates deeper, unseen contamination, requiring disposal of the entire product.
Understanding Different Cheese Types
Mold penetration varies significantly with cheese type. Hard and semi-hard cheeses, such as cheddar, Parmesan, Colby, and Swiss, have low moisture and dense textures, making it difficult for mold to spread beneath the surface. The mold tends to remain on the surface. Soft cheeses, including cottage cheese, cream cheese, ricotta, and soft goat cheese, are highly susceptible to deep mold penetration due to their high moisture and porous nature. Even if mold is only visible, its root-like structures (hyphae) can spread throughout the cheese, making it unsafe. Shredded, crumbled, or sliced cheeses should also be discarded if mold appears, as it can quickly contaminate the entire product.
Some cheeses, like blue cheese, Brie, and Camembert, are intentionally made with specific, edible molds that contribute to their unique flavors and textures. For example, Penicillium roqueforti creates blue veins in blue cheese, and Penicillium candidum forms the white rind on Brie and Camembert. However, if unwanted mold, such as black or dark red varieties, appears or is not characteristic of the cheese, it should be discarded.
Potential Risks of Mold
Mold on cheese poses health risks, especially when it indicates spoilage rather than intentional mold. Certain molds produce harmful mycotoxins, which can lead to allergic reactions, respiratory problems, or serious illness. Not all molds produce mycotoxins, but some common cheese spoilage molds, like Aspergillus and Penicillium species, can generate these toxic compounds. Aflatoxin M1 and ochratoxin A are hazardous mycotoxins found in cheese. Even if mold is only visible on softer cheeses, its microscopic root-like structures (hyphae) can penetrate deeply. This invisible spread means cutting off visible mold might not remove all contamination, leaving mycotoxins or other undesirable compounds. Mold growth can also be accompanied by harmful bacteria, such as Listeria, Salmonella, and E. coli, which cause foodborne illnesses.
Proper Mold Removal Techniques
For hard and semi-hard cheeses with superficial mold growth, specific techniques can safely salvage the product. The USDA and other food safety experts recommend cutting off at least one inch (2.5 centimeters) around and below the moldy spot. This margin helps ensure unseen hyphae or potential toxins are removed. When removing mold, keep the knife out of the mold itself to prevent cross-contamination. After cutting, rewrap the cheese in fresh packaging to avoid further mold growth. Before consumption, inspect the remaining cheese for discoloration or additional mold. If the cheese has an off-odor or taste, discard it entirely.
Preventing Mold Growth
Effective storage practices extend cheese shelf life and deter mold. Proper storage involves wrapping cheese in breathable materials to prevent excessive moisture loss, such as specialized cheese paper or parchment paper. Plastic wrap is discouraged for long-term storage as it can trap moisture, leading to slimy cheese and promoting mold growth. Storing cheese in the refrigerator’s crisper drawer, where humidity is higher and temperatures are consistent, maintains an optimal environment. The ideal temperature for cheese storage ranges from 35°F to 45°F (1°C to 7°C). To avoid cross-contamination, store different types of cheese separately and prevent contact with other moldy foods. Purchasing smaller quantities of cheese for consumption within a reasonable timeframe also minimizes mold development.