In the soft cheese, the plants contributing most to the ripening and to the formation of the flavor are what are commonly called molds, at least in some cheeses, while in the hard cheeses the molds play probably no part, and bacteria are the most active agents in producing the flavors developed during the ripening.
In making the soft cheeses—little known in this country—the general mode of procedure is as follows: The milk, sometimes whole milk, sometimes partly skimmed, is caused to curdle by the action of rennet. The curd is either cut to pieces by knives designed for the purpose, thus allowing the whey to drain off more readily, or it is simply ladled out of the vessel in which it curdled and placed at once into forms. As the whey is drawn off from the forms, through holes in the sides or through a false straw bottom, the curd soon assumes the shape of the forms. It is at first very soft, since it is subjected to no pressure whatever. At short intervals this soft mass is turned, so as to rest upon a new surface, and this turning is continued for two or three days. By this time the curd has become dry and consistent enough to handle, and it is then carried off to the cheese cellar for ripening. The details of this process differ considerably. In quite a number of cheeses particular methods are adopted to favor and hasten the growth of molds. Sometimes it is laid upon special straw mats or wrapped in straw, which, having been used over and over again in the dairy, has become thoroughly impregnated with mold spores. The cheese is then placed in a cool, damp atmosphere, which causes the spores to germinate and grow upon the cheese, already slightly acid, and in a condition favorable to the growth of molds. They grow rapidly over the whole surface of the cheese, and this step in the process is not ended until a good covering of molds has developed. Sometimes, indeed, special methods are adopted to insure their proper development. In making the Roquefort cheese specially prepared bread is allowed to mold, and after it becomes thoroughly impregnated with the mold it is finely grated to a powder and mixed with the curd as it is placed in the form for shaping. Fine holes are pierced in the cheese by a special machine to let in the air which is necessary for the luxuriant growth of the molds. Such treatment insures, of course, a very rapid growth of these plants, inside as well as outside. Most commonly, however, the cheese-maker depends upon his straw mats for the molds, and expects them to grow chiefly on the surface. The molds which develop in the cheese are not all of the same species. The common blue mold is most usual, but most cheeses are not properly ripened until several species of molds grow together within them.
The development of molds, however, is by no means the end of the ripening, but rather its beginning. Indeed, in some of the soft cheeses
