SALTING THE: BUTTKR 343 



kept without ice in cellar. Mohler, Washburn and Doane 1 re- 

 port as follows: "No dependence should be placed upon the 

 action of the salt that is added to butter as an agent in the 

 destruction of Bacillus tuberculosis. It has been shown that 

 the effect of salt as commonly used in the manufacture of but- 

 ter, is very slight at best. Most of the samples used were salted 

 with the usual amount. Yet the butter contained its virulence 

 for 6 months." 



These facts emphasize that the heavy salting of butter, as 

 usually practiced on the dairy farm where butter is made, is 

 not an adequate substitute for pasteurization and that pasteur- 

 ization is indispensible as a guarantee of freedom from disease 

 germs. 



Effect of Salt on Moisture Content of Butter. Before the 

 salt is added to butter, butter represents an emulsion of water- 

 in-fat, in which the water is present in very small drop- 

 lets, of relatively uniform size and even distribution. 



The addition of salt causes this emulsion to be disturbed. 

 The salt, owing to its great affinity for water, draws many 

 of the water droplets together into larger droplets and drops 

 and even larger aggregates. There is a marked decrease in 

 the number of small droplets and an increase in the number 

 'of large droplets. And there is an unmistakable tendency for 

 water to run out of the butter, causing a decrease in the per- 

 centage of moisture. 



In butter made from cream that was not sufficiently cooled, 

 nor held at the low temperature long enough to thoroughly 

 chill and harden the fat before churning, the salting invariably 

 produces a leaky body. In this case the mechanical-condition 

 of the fat is such that the formation of the water-in-fat emul- 

 sion, resulting during the churning process, is incomplete. While 

 it is sufficiently complete to prevent unsalted butter from being 

 leaky (unsalted butter never is really leaky) it is not suffi- 

 ciently complete to withstand the emulsion-disturbing influ- 

 ence of the salt. It yields to the salting-out process and be- 

 comes leaky. 



At best the salt tends to decrease the moisture content of 



1 Mohler, Washburn and Doane. Virility of Bacillus Tuberculosis, U. S. 

 A. I. 26, Annual Report, 1909. 



