Brands of d'Isigny are made from every grade between separator skim and whole milk. They reach the market in condition all the way from "Kosher" forms[56] which are eaten entirely unripe, to brands which approximate the qualities of Limburger and others which approach Port du Salut. The biology and chemistry of the ripening of this type of cheese have not been completely followed. An initial souring process always takes place quickly. _Oidium lactis_ is always present in some degree on the surface, but the organisms in the yellowish to orange slime on the surface of the cheese appear to produce the characteristic odor and taste. These appear to be due to the development of volatile fatty acids, such as valerianic and caproic, which diffuse throughout the cheese, even penetrating the unripened sour portions. The same odor and taste in varying intensity are present in Limburger, Brick, and a long series of German varieties not handled in America. High-flavored cheeses such as these, form an acceptable part of the meal in cases in which the intensity of other flavors is such as to mask entirely the milder flavors of Camembert or cream cheese. In composition, a characteristic whole-milk brand of this group showed the following analysis:[57] water, 45.5 per cent; fat, 25.28 per cent; protein, 18.22 per cent. +156. Raffiné.+[58]--This cheese is made in the French settlement of the Isle of Orleans in the St. Lawrence River. The practice seems to have been brought from France and represents an intermediate product between Camembert and perhaps Livarot, a cheese on the borderline between Camembert and Isigny as made in America. The outline of the making process as given follows: Milk freshly drawn is curdled without cooling, at approximately 90° F. The rennet is prepared on the farm. About one-half hour is required for curdling. The curd is cut into 2-inch cubes. Whey is removed as fast as it separates. About two hours are required for draining. The curd then goes into the hoops. The metal hoops, which are closed at one end, are 6 inches high, 4½ inches in diameter, with holes about 1/16 inch at intervals of about ½ inch, and stand upon three legs about 1 inch in height. When filled, the cheeses are left on a draining table. Some salt is put on top while draining. When the volume is reduced to one-half, the cheese is turned. The draining room is kept at about 70° F. After they are firm enough to handle, drainage is completed on racks covered with rush matting. These are arranged on special racks. The cheeses are turned twice a day, and washed in slightly salted water every two days. After each washing, they are drained for two hours on cloth, and placed on clean matting. This treatment continues about fifteen days.