Cottage cheese made by either the home or factory practice is a quickly perishable article. Although the acid restrains bacteria at first, the high percentage of water favors the growth of molds which tolerate acidity, especially _Oidium (Oospora) lactis_ and the Mucors or black molds. These molds destroy acidity rapidly and thus permit the bacteria of decay to develop and to produce objectionable taste and odors. Spoilage in these products is accelerated by the kneading process which distributes air throughout the mass and with it all forms of microbial contamination. +114. Buttermilk cheese.+--A cheese closely resembling cottage may be made from buttermilk. If the buttermilk came from cream which was churned before it became sour, the process is the same as that already described for the making of cottage cheese from skimmed-milk. If the buttermilk came from sour cream the process of manufacture is much more difficult. The casein of sour cream has already been coagulated with acid and broken during churning into very minute rather hard particles. These fine particles are difficult to recover. They are so fine that they pass through the draining cloth or at other times clog it and prevent drainage. They do not stick together at ordinary temperatures. They cannot be collected by the use of acid because they have already been coagulated with acid. After casein has been coagulated with acid, rennet extract will not recoagulate the particles. The buttermilk may be mixed with sweet skimmed-milk; then as the latter coagulates, it locks in the casein of the buttermilk so that it can be collected. If buttermilk from soured cream is used alone, the casein may be collected[34] by neutralizing and heating to 130 to 150° F., and holding until the casein gathers together. The whey can then be drawn off. Often there is further difficulty in getting the casein to collect, since the pieces remain so small that they go through the strainer. Cheese made entirely from buttermilk is sandy in texture and often not palatable. If the buttermilk with good flavor is mixed with skimmed-milk, it makes a good cheese closely resembling cottage. +115. Neufchâtel group.+[35]--The Neufchâtel process originated in northern France where a number of varieties are included under this as a group name. Among these are Bondon, Malakoff, Petit Suisse, Petit Carré. The name designates a general process of curd-making which is applied to skimmed-milk, whole milk or cream. Some of the resultant cheeses are ripened; some are eaten fresh. The Neufchâtel cheeses of France gained such wide recognition for quality that the process of making has become widely known. In America the manipulations of the French process were early dropped. The essentials were made the basis of a successful factory practice which has been widely adopted. The American factory practice is discussed here and the French process briefly considered under the heading Ripened Neufchâtel. (See Chapter VIII.)