What is blue cheese?
Blue cheese is called the french chesse known to belong to the
Rochefort family. It needs certain temperature and humidity
requirements and its is aged in some caves located in France.
[ADDED} Blue cheeses are by no means only French; nor are they
called "The French Cheese" - there are umpteen French cheeses of
all types. Local blue cheese varieties are also found in Britain,
and presumably other countries; and not all need cave ageing as
such but do need cool, slightly humid conditions.