What is the blue vein in French cheese?

The "blue vein" in French cheese is actually a mold, specifically Penicillium Roqueforti.

This mold is deliberately introduced during the cheesemaking process, giving the cheese its distinctive blue-green veins and its characteristic strong, pungent flavor.

Some famous French cheeses with blue veins include:

* Roquefort: The most famous blue cheese, originating from the caves of Roquefort-sur-Soulzon in the South of France.

* Bleu d'Auvergne: A milder blue cheese with a creamy texture, from the Auvergne region.

* Fourme d'Ambert: A semi-hard blue cheese with a slightly spicy flavor, from the Auvergne region.

So, next time you enjoy a French blue cheese, remember that the beautiful blue veins are actually a result of a carefully cultivated mold!