HISTORY AND DEVELOPMENT 25 



industry,, the practice of fractional sterilization was abandoned 

 for economic reasons. 



"The commercial part of the business also had its trials and 

 tribulations in introducing a new and comparatively inferior 

 product of comparatively high cost, and to overcome the prej- 

 udices of both the trade and the medical profession. 



"The problem thus confronting the company was to im- 

 prove the product, decrease its cost and improve selling methods 

 at the least possible cost." 



At first this unsweetened condensed milk, of relatively thin 

 consistency and pregnant with the cooked flavor resulting from 

 its exposure to high sterilizing temperatures, failed to appeal 

 to the public, who had become accustomed to the use of the 

 sweet, thick and semi-fluid sweetened condensed milk. But of late 

 years the demand for, and the manufacture of this product, 

 evaporated milk, has increased rapidly, until today, in this 

 country, its output by far exceeds that of sweetened con- 

 densed milk. 



Originally this unsweetened sterilized condensed milk was 

 labeled and sold under the name of "Evaporated Cream." The 

 Federal Food and Drugs Act of 1906 caused the name "Evapo- 

 rated Cream" to be changed to "Evaporated Milk." 



A further important step in the development of the manu- 

 facture of condensed milk occurred with the introduction of 

 the Continuous Concentrator, which machine was developed by 

 the By-Products Recovery Co., of Toledo, Ohio. This company 

 was organized in 1913 and their machine and process are covered 

 by numerous United States patents. The principle upon which 

 the Continuous Concentrator is constructed and operates is as 

 follows : 



"To rapidly move a film layer formation within a cylinder 

 having a heated surface, having means for escaping vapors and 

 means for keeping the surface bright and clean, circumferentially 

 and from the point of inlet to the point of outlet." 



Another type of the film principle of continuous concentra- 

 tion is represented in the Ruff Condensing Evaporator, manu- 

 factured by the Cream Production Co., Port Huron, Mich. 



The Continuous Concentrator in its present improved form 

 has reached a state of perfection that renders this machine appli- 



