456 MANUAL OF MILK PRODUCTS 



authoritative estimate that about 3 gallons of water are required 

 for the condensing of 1 pound of fresh milk (about 1 pint). 

 Difficulty in obtaining an adequate supply of good, pure, cold 

 water is a cause of serious embarrassment to some of the com- 

 mercial condenseries now established, and the lack of it has 

 been the cause of many failures. 



Third. An abundant supply of pure milk is an absolute 

 necessity. The exact quantity required daily will, of course, 

 vary with the size of the plant. Several reliable authorities 

 have estimated that for the profitable production of condensed 

 milk on a commercial scale the supply of raw milk to the factory 

 should not fall below 15,000 pounds a day. This estimate is 

 exclusive of the daily supply of milk normally required for 

 other purposes by the community. Furthermore, if the finished 

 product is to be of marketable quality, the milk received at the 

 condensery must be of exceptionally high grade ; that is, clean 

 and pure. 



While first-class milk is essential for the manufacture of a 

 first-class dairy product of any kind, it is absolutely necessary 

 if a condensed-milk factory is to be a success. If a few cans of 

 low-grade milk are not detected at the receiving platform of a 

 condensery, the slight defects in the raw milk are multiplied in 

 the process of condensing it, and the result is practically certain 

 to be the complete loss of the whole batch, which may represent 

 a financial loss of several hundred dollars. This statement may 

 be illustrated concretely : It is claimed by authorities that raw 

 milk containing as much as 0.2 per cent acid (calculated as 

 lactic acid) is not fit for condensing purposes. This does not 

 necessarily mean that it would taste sour, but if accepted and 

 condensed in the ratio of 2.25 to 1 (it may be more but is seldom 

 less), the acidity, increasing in the same ratio, would reach 0.45 

 per cent, which would be practically certain to cause a sour taste 

 in the finished product. Every housewife knows that sour 

 milk will coagulate or curdle on heating, and that the higher the 



