MILK 



3804 



MILK 



as food ; milk has protein, fat and carbohydrates 

 about in equal quantity; bread has practically 

 no fat, and meat has practically no carbohy- 

 drates. Either bread or milk alone is a better 

 diet than meat alone, and milk and bread to- 

 gether are an excellent diet, especially for 

 children. For adults, milk and bread should 

 be supplemented by meat and other foods. In 

 its uncooked form milk may be added to 

 coffee, tea and chocolate, and it may be used 

 in making bread, cake, pastry and many cooked 

 foods. Cream, which contains most of the fat 

 of milk, and butter, which is made from cream, 

 are valuable for supplying energy. Cheese, 

 which contains both fat and protein that is, 

 the casein supplies building material for the 

 body, as well as energy. Sour milk, containing 

 bacteria which are not harmful when taken into 

 the body, is used to a considerable extent in 

 cooking, in making cottage cheese, and in the 

 preparation of koumiss. 



Babcock Test. This name is applied to a 

 method of determining the amount of butter 

 fat in milk, invented by Dr. S. M. Babcock of 

 Madison, Wis. The apparatus consists of a 

 closed cylindrical box containing a rack for 

 holding bottles, so mounted that it can be re- 

 volved rapidly by hand power or by a motor, 

 and several glass bottles, a pipette and an acid 

 measure. 



The first step in making the test is to mix 

 the milk thoroughly by pouring it several times 

 from one vessel to another, for the purpose of 

 securing an even distribution of the butter fat. 

 This should be done as soon as possible after 

 the milk is drawn. The necessary quantity of 

 milk for a test is then drawn up into the 

 pipette and placed in the testing bottle. An 

 equal quantity of sulphuric acid is then poured 

 into the acid measure and then into the bottle 

 containing the milk. The acid and milk are 

 then thoroughly mixed by giving the bottle a 

 rotary motion and at the same time shaking it 

 gently. After several bottles, each containing 

 milk from different lots, have been prepared 

 they are placed in the centrifuge, which is ro- 

 tated at a speed varying from 700 to 1,200 

 revolutions per minute, for about five minutes. 

 A small quantity of warm water is then added 

 to the bottles, and they are again rotated for 

 about two minutes. If the work has been 

 properly done, all the butter fat rises in the 

 neck of the bottle, which is marked with a 

 graduated scale that tells at a glance the per- 

 centage of butter fat that the milk contains, and 

 therefore its richness. 



Condensed Milk. This is fresh milk which 

 has first been sterilized, and then reduced to 

 about one-fifth of its bulk by the evaporation 

 of part of the water it contains. In other 

 words, about five quarts of fresh milk are re- 



BABCOCK TESTER 

 A small machine, with hand power. 



quired to make one quart of condensed milk. 

 When fresh milk is brought to the factory it is 

 placed in large storage tanks, from which it is 

 drawn off into smaller copper tanks, each hold- 

 ing about 1,000 gallons. By steam heat the 

 milk is brought to the boiling point, and is 

 then strained into the sugar mixer, where the 

 proper proportion of cane sugar is added. 

 Usually the proportion is about seven ounces 

 of sugar to one pint of milk. Some condensed 

 milk is sold fresh and unsweetened; this is 

 usually called "evaporated," to distinguish it 

 from the sweetened, or condensed, variety. 

 After the sugar is added the milk is placed in 

 vacuum pans, heated to a temperature of 140 

 F., and evaporated until seventy-five to eighty 

 per cent of the water is gone. The milk is 

 thus reduced to a thick, pasty, cream-colored 

 mass, which is taken to the cooler and then to 

 the packing-room, where it is sealed in air- 

 tight cans ready for shipment. E.H.F. 



Consult Farrington and Wall's Testing Milk 

 and Its Products; Wing's Milk and Its Products. 



Related Subjects. The reader is referred to 



the following articles in these volumes : 

 Adulteration of Food- Casein 



stuffs and Clothing Cattle 

 Albumen Cheese 



Butter Cookery 



Buttermilk Dairying 



Calorie Diet 



Carbohydrates Food 



