DETERMINING QUALITY OF MILK FOR CONDENSERIES. 11 



A composite sample of the milks showing coagulation with alcohol, 

 along with a sample of that showing no coagulation, was run in 

 the laboratory apparatus as a means of comparison. Out of 4 trials 

 the raw milk showing coagulation with alcohol gave an evaporated 

 milk that in all 4 cases showed curdiness after sterilization at the 

 standard temperature, while the evaporated milk from the raw 

 milks showing no coagulation with alcohol showed curdiness in 3 

 out of 4 cases. The 4 batches of milk, the individual cans of which 

 showed no coagulation with alcohol and which were run in the 

 large factory pan, all showed curdiness after sterilization. Several 

 laboratory runs made on milk taken from the large receiving vat 

 at different times, to get representative samples of the milk received, 

 failed in all instances to give an evaporated milk that would meet 

 the required standard and not show curdiness after sterilizing and 

 shaking. 



The general failure of milk, accepted on the acid test at this con- 

 densery, to withstand the necessary heat after being evaporated, 

 suggested that it might be due to a deficiency in the composition 

 and balance of milk salts, as reported by Sommer and Hart (2). 

 The fact that the addition of a small amount of dibasic potassium 

 phosphate, which is a normal constituent of milk, corrected the 

 excessive tendency of the milk to curdle in sterilization indicates 

 that this assumption was correct. 



Consideration of the manner in which milk at this plant was 

 handled, in connection with the results obtained, indicates that the 

 conditions were quite different from those that the average con- 

 densery has to contend with, and for this reason it appeared highly 

 desirable to try out the alcohol test at another place. 



WORK AT FACTORY B. 



The work was then continued in a condensery, designated Factory 

 B, located in a region where dairying forms a minor part of the 

 farm operations. As a result of this condition the milk received 

 was not of good quality. All the work done at this plant was on a 

 commercial basis, the milk being graded at the intake and run into 

 separate tanks according to its reaction with alcohol. Separate runs 

 of the milk showing, respectively, coagulation and no coagulation 

 with alcohol, were made in the factory pans, and after retaining the 

 required amount of each batch of evaporated product for the experi- 

 mental work, they were mixed in one tank and handled in the usual 

 manner by the factory. Because of the small proportion of milk 

 received that showed coagulation with alcohol, the batches from this 

 kind of milk were smaller and in some cases it was necessary to hold 

 them over until the next day in order to get enough for a run in the 



