The method described above is that followed in practically all the factories of the United States and Canada. About 90 per cent of the cheese manufactured is of this character. The remainder is farm-made, or made in urban dairies, or else is manufactured by some other process in imitation of some foreign cheese, as the Swiss Gruyere or Emmenthal, Limburger, Neuchatel, Brie, etc.
The constituents of milk which determine its value for cheese-making are the fat and casein. Milk may contain from 3 to 8 per cent of fat and from 2 to 5 per cent of casein, the average proportion being about a pound of fat to two thirds of a pound of casein. Since the cheese yield increases with the fat in the milk, managers of cheese factories have encouraged the production of milk rich in fat, and perhaps this knowledge is largely responsible for the fact that in 1900, in the factories of the United States, 100 pounds of milk made almost 17 per cent more cheese than it did in 1890.
The analysis of cheese is largely a matter of securing a correct average, as a cheese varies in properties at the centre or at the circumference. A wedge is generally taken as a sample, cut from the centre to the rind, or sometimes a plug, taken at one-third the dis tance from the rind to the centre. The usual test of cheese is to find the proportion of fat. For this purpose the Association of Official Agricultural Chemists of the United States De partment of Agriculture have adopted the fol lowing method: For the estimation of fat in cheese about 5 grams should be carefully weighed. and transferred as completely as pos sible to a test bottle. From 12 to 15 c.c. of hot water are then added and the bottle shaken at intervals, keeping it warm until the cheese has become softened and converted into a creamy emulsion. This may be greatly facilitated by the addition of a few drops of strong ammonia to the con tents of the bottle. After the contents of the bottle have become cold the usual amount of acid should be added and the bottle shaken until the lumps of cheese have entirely dissolved. The bottles are then placed in the machine and whirled, the test being completed in the same manner as with milk. To obtain the percentage of fat the reading should be multiplied by 18 and divided by the weight in grams of cheese taken.
Some cheese is colored by the makers, though the best requires no coloring. Saffron and arnotto are used for this purpose. Various herbs are also incorporated with the milk at the time of making the curd, to alter the appear ance or flavor of the cheese. Common among these are sage leaves, marigold and parsley.
A small proportion of the cheese used in the United States is imported. From 5,000,000 to 7,000,000 pounds a year of Swiss cheese are brought in, also some from France, Germany and England. In 1910 40,817,524 pounds o. cheese were imported, while the exports were but 2,846,709 pounds. The value of the imports was $7,053,570; the exports about $442,000. Such cheese is usually named from the locality whence it comes, though sometimes the name becomes distinctive of a special make, as the Roquefort, which is made from the milk of sheep, mainly the Larzac breed; the Kachkaval (Bulgarian), a white cheese made of sheep's milk; the Parmesan (Italian), which is kept three or four years and polished with linseed oil and charcoal till it shines like ebony; the Limburger (German), characterized by its strong odor; and the Brie (French), which is also odoriferous.
Previous to 1850 practically all the cheese made in this country was a farm product. Jesse Williams started the first cheese factory in the United States in Oneida County, N. Y., in 1851; between then and 1860 factories were established in New York State at the rate of three or four a year, and from the latter date the growth of the industry in New York was rapid, as follows: 1860, 17 new factories; 1861, 18 more; 1862, 25; 1863, Ill ; 1864, 210; 1865, 52; 1866, 46. Since that date the growth has been a normal one.
The United States census classes butter, cheese and condensed milk factories together, and gives the total establishments in 1914 as 7,982. These concerns manufactured in 1914 products worth $370,818,729, but most of this value is milk and butter, cheese representing only about one-sixth of the industry. The fac tory production of cheese in 1914 was 377,506, 109 pounds, in value $50,931,925, or about cents a pound. Nine-tenths of this production was full cream cheese.
Wisconsin, where the industry began in 1864, has been the leading State in cheese-mak ing for some years, with an annual production valued at about $9,000,000; other States aver age: New York $6,600,000, Minnesota $4,300, 000, Illinois $2,000,000. Considerably higher figures have been given by some authorities, but this is due to other oroducts of the dairy, as condensed milk, being figured in with the cheese.
For further information regarding cheese see Decker's 'Cheese Making> (1905), the United States census reports and reports of the New York State Agricultural Experiment Sta tion and the Wisconsin Agricultural Experiment Station; also the yearbooks and bulletins of the Department of Agriculture.