TABLE XXIII
SHOWING THE AVERAGE YEARLY PRICE OF CHEESE, 1892-1916
YEAR CENTS 1892 9.4 1893 9.4 1894 9.7 1895 9.1 1896 8.4 1897 9.1 1898 8.6 1899 8.6 1900 10.2 1901 9.9 1902 10.1 1903 11.9 1904 10.5 1905 10.7 1906 11.7 1907 11.6 1908 12.9 1909 12.6 1910 15.5 1911 12.4 1912 14.2 1913 17.0 1914 17.1 1915 15.3 1916 16.7
The graph (Fig. 68) shows that the average yearly price has increased from 9.4 cents a pound to 16.7 cents.
[Ill.u.s.tration: FIG. 68.--Average yearly price of cheese.]
+306. Canadian cheese statistics.+--The following statistics show the development of the industry in Canada. The figures in Table XXIV show the number of cheese factories, the amount of milk received and the total production in Canada.
Table XXIV indicates that the number of cheese factories has decreased but that the production has increased. Because of the scarcity of figures, conclusions would not be accurate.
The figures in Table XXV of the exports and imports show that the exports gradually decreased and the imports increased. If the production has increased, as shown in Table XXIV, more cheese must be consumed by the Canadians. The effect of the war is probably seen in the year 1916, when the imports are decreased and the exports increased.
TABLE XXIV
SHOWING THE NUMBER OF CHEESE FACTORIES, AMOUNT OF MILK RECEIVED AND THE FACTORY PRODUCTION OF CHEESE
-------+------------+---------------+---------------NUMBER OFPOUNDS OFFACTORY YEARCHEESEMILKPRODUCTIONFACTORIESDELIVEREDOF CHEESE -------+------------+---------------+--------------- 1900--------220,833,2691907--------204,788,58319102291----199,904,205191518711,501,946,221183,887,837191618131,503,997,215192,968,597 -------+------------+---------------+---------------
TABLE XXV
SHOWING THE AMOUNT AND VALUE OF CANADIAN EXPORTS AND IMPORTS OF CHEESE
------+--------------------------+---------------------- YearExportsImports ------+-------------+------------+-----------+----------Amount inValue inAmount inValue inpoundsdollarspoundsdollars ------+-------------+------------+-----------+---------- 188040,368,000$3,893,000189094,260,0009,372,2121900185,984,00019,856,3241910180,859,00021,607,692683,778----1911181,895,00020,739,507866,653----1912163,450,00020,888,818919,189----1913155,216,00020,697,0001,495,758----1914144,478,00018,866,0001,512,108----1915137,601,00019,213,0001,162,456----1916168,961,000----971,821---- ------+-------------+------------+-----------+----------
If the total population of the United States is figured at 100 million and the difference between the exports and imports found and added to the total production, it shows that the average person must consume about three and one-half pounds of cheese in a year.
In the past few years there has been considerable demand for more of the foreign cheeses, such as Camembert and Roquefort.
+307. Introduction of cheese-making into new regions.+--The manufacture of Cheddar cheese is being encouraged in new regions, in the Alleghany Mountains, in Virginia, West Virginia, North Carolina, Tennessee and in the western states. There has also sprung up a considerable demand for the lactic acid group of cheeses, especially Neufchatel and Cottage, so that while the cheese industry may decline in certain sections, the total production will probably increase. In the proper locations or sections, the cheese industry has a very bright future. The development of the skimmed-milk cheeses will undoubtedly be given considerable attention in the next few years.
REFERENCES
N. Y. Dept. Agr. Bul. 54, The Dairy Industry in New York State.
N. Y. Produce Rev. and American Creamery.
Vol. 34, No. 3, page 108.
Vol. 37, No. 16, page 684.
Vol. 37, No. 16, page 666.
Vol. 37, No. 9, page 411.
Vol. 33, No. 11, page 482.
Vol. 36, No. 23, page 1078.
Wis. Exp. Sta. Rept. 1897, pages 113-149.
U. S. Census.
U. S. Dept. Agr. Year Books.
Bureau of Foreign and Domestic Commerce.
Statistical abstract of the U. S.
Canadian Dept. Agr. 1915, Report of the dairy and cold storage commissioner.
Dominion of Canada, Census and Statistics office, Rept. 1915.
CHAPTER XIX
_TESTING_
In connection with marketing, a certain amount of testing of the products should be practiced, to determine exactly the results and grades of products. This includes the testing of the whole milk, whey and cheese for fat, the milk for casein, and the cheese for moisture. In factories in which the milk is bought on the fat basis, it is necessary to test each patron"s milk for fat. If there is a cheese-moisture law in the state, it is necessary to test for moisture. The whey should be tested to learn the loss of fat in the manufacturing process and to ascertain whether the losses have been reduced to the minimum.
+308. The fat test.+--The test commonly used to determine the fat in milk is known as the Babc.o.c.k. The principle of this test is as follows: Fat exists in the form of very small globules. Because the fat globules are lighter than the other milk const.i.tuents, under the influence of the force of gravity most of them rise to the surface. There, mixed with the other milk substances, these globules form a layer of cream. Babc.o.c.k found that by adding to the milk sulfuric acid of proper strength and temperature, the casein, the milk-sugar and the alb.u.min are decomposed and the sticky quality of the milk is destroyed. The acid does not decompose the fat but leaves it free to come to the surface of the mixture. Under centrifugal force, this fat is quickly brought to the surface. By using a known quant.i.ty of milk and having a scale graduated in percentage of the amount of milk, the percentage of fat can be determined. Fig. 69 shows the necessary equipment.
[Ill.u.s.tration: FIG. 69.--Apparatus necessary to test milk and whey for fat and total solids.]
There are three kinds of bottles employed in making the test, one with a very large neck which is used when testing materials high in fat-content such as cream, b.u.t.ter and cheese. This is generally called a cream-test bottle. It is graduated from 0 to 50 per cent. When testing materials with a small amount of fat such as whey, skim-milk and b.u.t.termilk, a test bottle with two necks is used, one with a small bore for the fat and the other neck with a larger bore to add the milk, acid, water. It is graduated from 0 to 0.5 of 1 per cent. There is a third bottle between the other two to test whole milk. This is known as a whole-milk bottle. It is graduated from 0 to 8 per cent. All of the gla.s.sware should comply with the laws.
+309. Sampling the milk.+--One of the most important parts of testing is to obtain a fair sample of the milk. The milk to be tested may be in a vat or in a farmer"s can or a composite sample jar. If the milk is bought on the fat basis, that of each patron is not tested daily, but a small quant.i.ty, about half an ounce, is taken each day and placed in a jar; this is known as a composite sample. It is the usual practice to number the patrons and have a sample bottle for each patron with his number on it. Some substance must be added to preserve the milk and to keep it from souring or coagulating. It is difficult to secure a fair sample of sour milk. A wide-mouthed jar is preferred for keeping milk samples. This must be kept closed to prevent evaporation. Each day when milk is added to the composite sample, the bottles should be shaken to prevent the cream drying. Composite samples are tested at least twice a month. The milk may be mixed to obtain a fair sample, by stirring in the vat or by pouring from one bottle to another. Vigorous shaking should be avoided as this is likely to cause churning. One should see that all the cream is removed from the sides of the sample bottle and that it is evenly distributed through the milk. The sample of milk is now measured out with the pipette. This is graduated to deliver 18 grams of milk, and holds 17.6 c.c. Hold the pipette between the thumb and second finger of the right hand with the tip below the surface of the milk, draw the milk by suction with the lips until it is filled well above the graduation.
Quickly place the forefinger over the opening and at right angles to the pipette. By gently and carefully raising the forefinger, allow the milk to run down until the surface is exactly level with the graduation. To obtain an accurate reading, the pipette should be on a level with the eye. Then with the left hand, hold the milk test bottle in a slanting position and place the tip of the pipette into it about one-third of an inch and at a slight angle. Now let the milk slowly flow down the side of the neck of the bottle, making certain that none is blown out by the escaping air. When all has run out of the pipette, blow out the drop which remains in the tip. Then measure out another sample in the same way, as the test should be made in duplicate.
+310. Adding the acid.+--The sulfuric acid should have a specific gravity between 1.82 and 1.83. It should be kept in gla.s.s-stoppered bottles or carboys to prevent the absorption of moisture from the air, which will reduce its strength. Acid that is too strong might burn the fat. The acid is a strong poison and will burn if it comes in contact with the flesh or the clothing. In such case, it should be removed by washing with plenty of water. An alkaline substance such as ammonia or bicarbonate of soda should be applied to remove any acid not washed away.
The acid measure holds 17.5 c.c. and it should be filled to the graduation. Then this acid should be added to the test bottle. The bottle should be held at an angle and slowly rotated so that the acid will rinse down any milk remaining in the neck of the bottle.
Immediately mix the acid and milk by whirling the body of the bottle in a circle five or six inches in diameter. The mixture should not be allowed to go into the neck of the bottle while mixing. Continue shaking for about a minute after all the curd has disappeared. One should avoid pointing the neck of the bottle toward any person in the mixing operation. The acid unites with all the milk substances except the fat and generates much heat.
+311. Centrifuging.+--There are two machines in common use for centrifuging, one that runs by mechanical power and the other smaller and runs by hand. If the machine and atmosphere are very cold, the apparatus can be warmed by placing hot water in it. This is not necessary in a steam machine. In a factory where there are a number of samples to test, a power machine is usually employed. In this machine there are pockets or cups in which to set the test bottles. The machine or disk must be balanced by placing bottles in opposite pockets. These pockets are hinged so that when standing still the bottle is in an upright position and when the centrifuge is running, it is in a horizontal position. The machine should then be covered and started running. It should be run at the speed indicated. After five minutes, stop the machine and fill the bottles with boiling water up to the neck.
This can be done without taking the bottles out of the machine. A pipette or slender-spouted vessel may be used to add the water. Whirl the bottles two minutes, then add more boiling water to bring the fat column into the graduated part of the neck of the bottle. Then whirl one minute. The test should be read at once or the bottles kept at a temperature of 130 to 140 F. until ready to read.
+312. Reading the test.+--To read the test, subtract the reading at the bottom of the fat column from that at the highest point. The curved meniscus which always forms at the top of the fat column should be included in the reading. Duplicate samples should not vary more than O.2 of 1 per cent. Standard Babc.o.c.k test bottles and pipettes should always be used. In some states the agricultural experiment stations examine all gla.s.sware and mark it to make certain that it conforms to the requirements of the state law. In New York, gla.s.sware found to be correct is branded "S. B.," which means State Brand. In some states a person must have a license to test milk or cream, when it is paid for on the fat test. Such a person must pa.s.s an examination to show that he understands the test before a license, will be granted. The license may be revoked if the work is not honestly performed.
+313. Testing whey for fat.+--Because of the small amount of fat in whey, it is difficult to obtain a representative sample. The best way, if the entire amount cannot be placed in a vat and stirred, is to catch a little of the whey at intervals as it is being drawn from the vat. The sample to be tested is measured with the pipette the same as the milk and placed in the skimmed-milk test bottle. The same acid is used to test whey as to test milk but because there are not so many solids to destroy, not so much is used. If as much acid is used with whey as with milk, it will burn the fat and so interfere with the reading of the test. Just enough acid is added to destroy the milk substances except the fat, or enough to turn the contents of the test bottle dark brown.
This usually requires filling the acid measure one-quarter of an inch under the graduation. The remainder of the test is the same as for whole milk.
+314. Testing cheese for fat.+--The sample of cheese to test for fat is obtained by removing the sample with a cheese-trier. This sample is called a "plug." Different plugs from the same cheese will test various percentages of fat so that it is difficult to secure a representative sample. The usual practice is to take three plugs, one near the center, another near the outside and the third between the first two. The plugs should be put into gla.s.s-stoppered bottles to prevent the evaporation of moisture. These plugs are then chopped up very fine. It is of course impossible to measure the cheese as with milk and whey, but it is weighed (Fig. 70). If the cheese is soft it can be stirred with a spatula until well mixed. A soft cheese usually sticks to the neck of the test bottle. After being weighed, it can be dissolved in a little sodium hydroxide and poured into the bottle. Different amounts may be used, commonly 4 or 6 grams, but 6 grams is to be preferred. This is placed in the Babc.o.c.k cream bottle since there will usually be more fat than can be read in a milk bottle. After the material has been placed in the test bottle, about two-thirds of an acid-measure of warm water is added to a.s.sist in dissolving the cheese.
[Ill.u.s.tration: FIG. 70.--Apparatus necessary to test cheese for fat.]