Blue Cheese's Pre-Mold Identity: A Dairy Mystery Explained

Blue cheese is made using a type of mould called Penicillium, which is responsible for its distinct taste, smell, and appearance. Unlike other types of mould, the types of Penicillium used to produce blue cheese do not produce toxins and are considered safe to consume. Blue cheese is believed to have been discovered by accident when cheeses were stored in caves with naturally controlled temperatures and moisture levels, which happened to be favourable environments for various harmless moulds. One of the first blue cheeses, Roquefort, was discovered when a young boy abandoned his bread and ewes' milk cheese in a cave after seeing a beautiful girl in the distance. When he returned months later, the mould (Penicillium roqueforti) had transformed his cheese into Roquefort.

Blue cheese is made using a type of mould called Penicillium

Penicillium roqueforti is the mould responsible for the blue veins in Roquefort, Stilton, and Gorgonzola cheeses. It is also added to the curds of the cheese after they have been formed and drained. The mould then grows inside the air tunnels created by piercing the cheese with needles or skewers, developing flavour as it ages. This process typically takes three to six months.

Penicillium glaucum is the mould used to create the blue-green veins in Gorgonzola cheese during the ripening process.

While other types of mould produce compounds called mycotoxins, which are toxic to humans, the varieties of Penicillium used in cheesemaking do not produce toxins and are safe to consume.

The discovery of blue cheese is believed to have occurred by accident when cheeses were stored in caves, where they were exposed to naturally occurring moulds. According to legend, one of the first blue cheeses, Roquefort, was discovered when a young boy left his bread and ewes' milk cheese in a cave and returned months later to find that the mould (Penicillium roqueforti) had transformed his cheese.

Blue cheese was discovered by accident

Blue cheese is believed to have been discovered by accident. According to legend, the first blue cheese, Roquefort, was created when a young boy abandoned his lunch of bread and ewes' milk cheese in a cave after spotting a beautiful girl in the distance. When he returned to the cave months later, the cheese had been transformed by the mould Penicillium roqueforti.

Another legend tells of a distracted shepherd who forgot his lunch of bread and cheese in a cave outside the village of Roquefort in France. When he returned a few months later, his cheese had become infested with the same mould, Penicillium roqueforti, which was growing in the cave.

The process of making blue cheese involves adding mould cultures to milk, which create blue-green spots or veins throughout the cheese. The mould used to make blue cheese, Penicillium, does not produce toxins and is safe to consume.

Analysis of ancient faeces sampled in the salt mines of Hallstatt, Austria, showed that blue cheese was consumed as far back as 800 to 400 BC.

Blue cheese is aged for 2-3 months

During the ageing process, the temperature and humidity of the room are carefully monitored to ensure the cheese does not spoil or lose its optimal flavour and texture. The ripening temperature is usually around eight to ten degrees Celsius, with a relative humidity of 85-95%. However, these conditions may vary depending on the type of blue cheese being produced.

At the beginning of the ageing process, the cheese loaves are punctured to create small openings that allow air to penetrate and support the growth of the Penicillium roqueforti cultures. This encourages the formation of the distinctive blue veins of blue cheese. The veins are also responsible for the cheese's aroma.

The longer the ageing process, the more pronounced the flavour of the blue cheese will be. Most blue cheeses are aged for three to six months. However, a fermentation period of 60-90 days is usually needed before the flavour is typical and acceptable for marketing.

Blue cheese can be stored in the refrigerator for 3-4 weeks

Blue cheese is made by adding mould cultures to cheese milk. The mould used is often Penicillium roqueforti, which grows in the air tunnels that are created when the cheese is pierced with thin needles or skewers. The blue mould then matures inside these tunnels, developing flavour as it ages.

When wrapping blue cheese, it is important to let it breathe. While plastic wrap is acceptable, paper, such as butcher paper or waxed paper, is preferable. It is also recommended to rewrap the cheese each time it is used. This will help to prevent moisture buildup and keep the cheese fresh.

It is worth noting that freezing blue cheese is an option if you wish to extend its shelf life further. To freeze blue cheese, cut the cheese into portions no larger than half a pound each and wrap them tightly in heavy-duty aluminium foil or plastic freezer wrap, or place them in a heavy-duty freezer bag. Properly stored, frozen blue cheese will maintain its best quality for about six months but will remain safe beyond that time.

Blue cheese is made from raw or pasteurised milk

Blue cheese is made from either raw or pasteurised milk, depending on the variety. For example, Stilton blue cheese is made from pasteurised milk, whereas Stichelton blue cheese is made from raw milk.

Raw milk is unpasteurised and, as such, contains a rich array of flavour-building enzymes and bacteria. When milk is heated, as it is during the pasteurisation process, many of these naturally occurring, flavour-rich enzymes are destroyed or denatured. Raw-milk cheeses are often valued for their unique, complex flavours and aromatics. They also impart a 'terroir' or 'taste of place', reflecting the unique characteristics of the land where the cheese is made.

However, raw milk can contain harmful pathogens, such as listeria, salmonella, and E. coli. Since 1949, the U.S. government has forbidden the sale of cheese made from unpasteurised milk unless it has been aged for at least 60 days. This ageing process is important because, after 60 days, the acids and salts in raw-milk cheese naturally prevent harmful bacteria from growing.

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