Cheese in the categorization of these cheeses is their age. Fresh cheeses without additional preservatives can spoil in a matter of days. Content (double cream, goat, ewe and water buffalo) Some cheeses are categorized by the source of the milk used to produce them or by the added fat content of the milk from which they are produced. While most of the world's commercially available cheese is made from cows' milk, many parts of the world also produce cheese from goats and sheep. Some cheeses are described by their fat content. Double cream cheeses are soft cheeses of cows' milk enriched
Stilton cheese stocked a generic "British Blue cheese". Other makers have adopted their own names and styles. Other examples of blue cheeses include Gorgonzola cheese of Italy, which is made from cows' milk; and the French cheeses Fourme d'Ambert from Auvergne and made with cows' milk and Roquefort, which is made with ewes' milk. Blue Stilton is often eaten with celery or pears. It is also commonly added as a flavouring to vegetable soup, most notably to cream of celery or broccoli. Alternatively it is eaten with various crackers, biscuits and bread. It can also be used to make a blue cheese