Blue cheese is a distinctive culinary creation, recognized globally for its unique appearance and pungent flavor. Its characteristic blue-green veins and strong aroma set it apart. This unique nature often sparks curiosity about the “fungus” responsible for its distinct qualities.
Meet the Fungi of Blue Cheese
The signature appearance and flavor of blue cheese come from specific types of fungi, primarily Penicillium roqueforti and, to a lesser extent, Penicillium glaucum. Penicillium roqueforti is used in many blue cheeses, such as Roquefort, Stilton, and Danish blue. Penicillium glaucum is found in varieties like Gorgonzola, Bleu de Gex, and Rochebaron.
These fungi are intentionally introduced during cheesemaking to ensure their growth throughout the cheese. Cheesemakers inoculate the milk or curd directly with fungal spores. To facilitate internal mold growth, cheese wheels are often pierced, creating small channels for oxygen circulation. This controlled environment, with specific humidity and oxygen levels, promotes the desired fungal development as the cheese matures.
How the Fungus Transforms Cheese
The fungi in blue cheese profoundly alter the cheese’s flavor, aroma, and texture through various biochemical processes. Penicillium roqueforti effectively breaks down both fats and proteins within the cheese. This metabolic activity directly contributes to the pungent and distinctive taste of blue cheeses.
Lipases, enzymes produced by the mold, break down milk fats into shorter fatty acid chains. These fatty acids are then converted into compounds like methyl ketones, which impart the characteristic sharp, tangy, and sometimes slightly sweet or metallic notes. Simultaneously, proteases from the fungi break down milk proteins into smaller peptides and amino acids, softening the cheese’s texture and enriching its complex aroma. The visible blue-green veins are formed by the mold’s mycelia, networks of thread-like filaments that grow and spread throughout the cheese where oxygen is available.
Is Blue Cheese Fungus Safe to Eat?
Despite its appearance, the specific fungi used in blue cheese are entirely safe for human consumption. While many associate mold with spoiled food, the Penicillium species in blue cheese, such as Penicillium roqueforti and Penicillium glaucum, are distinct from harmful molds that produce toxins. These particular strains do not produce mycotoxins, chemical substances harmful if ingested.
Cheesemakers maintain a highly controlled environment during blue cheese production and aging. This careful management ensures the growth of only desired, safe fungal cultures and prevents the development of undesirable molds that could compromise safety or flavor. Therefore, the mold in blue cheese is not only harmless but is deliberately cultivated to create its unique characteristics.