332 MAI/TED MILK 



heated air, is not as economically and as efficiently utilized as heat 

 in the form of steam applied in steamed-heated metal drums. 



While, as previously shown, the spray-drying process is the only 

 process of desiccating milk, that preserves the original solubility of 

 the milk, this advantage is lost in the case of buttermilk. The acid 

 in the buttermilk has changed the casein from its fine emulsion, 

 such as it represents in normal milk, to a condition which renders 

 the particles of casein, or curd, incapable of permanently remulsi- 

 fying. The curd in commercial buttermilk does not stay in emul- 

 sion, but settles to the bottom. Hence nothing is gained by drying 

 the buttermilk by the more expensive process of spray-drying. The 

 film process, which is the more economical, is therefore better 

 adapted for the manufacture of buttermilk powder than*the spray- 

 drying process. 



It is advisable .to precondense the buttermilk, before desiccat- 

 ing, at the ratio of about 2:1. 



One gallon of buttermilk yields about .72 pounds of buttermilk 

 powder, or the manufacture of one pound of powder requires 

 about 1.39 gallons of buttermilk. The cost of manufacture is esti- 

 mated at about 2 cents per pound of buttermilk powder or about 

 1.44 cents per gallon of buttermilk. 



Whey powder is manufactured in a similar manner. Its chief 

 value lies in its usefulness in the diet of infants and invalids, with 

 whom the consumption of casein produces digestive disturbances. 

 Since fresh whey is often not obtainable, the whey powder, the good 

 keeping quality of which permits of keeping it on hand, furnishes 

 an admirable substitute. When made from sour whey, it offers 

 many advantages in cooking and baking and should be especially 

 well suited for such dishes as pan cakes, .etc. 



MALTED MILK. 1 



Definition. The product known as malted milk is that re- 

 sulting from the combination of whole milk with the extract of 

 malted barley and wheat flour, and the mixture is reduced to a dry 

 form by desiccation in vacuo. 



History of Malted Milk Industry. The process of the manu- 

 facture of malted milk was invented by Mr. William Horlick, of 



1 Information on Definition. History and Process of Manufacture, received 

 through the courtesy of Horlick's Malted Milk Co., Racine, Wis., March 8, 

 1918. 



