ADULTERATIONS OF CONDENSED MILK 275 



is to make the sugar in these products precipitate in the form of 

 very fine and soft crystals. Condenseries, which have been con- 

 tinually troubled with sugar crystallization and sugar sediment, 

 have tried to overcome this defect by adding cream of tartar to 

 the sweetened milk in the vacuum pan. Cream of tartar is an 

 acid salt (acid potassium tartrate, KH.C 4 H 4 O 6 ), and it is this 

 acid which in the manufacture of candy causes the fine and soft 

 grain of the sugar. It is obvious that if enough cream of tartar 

 were added to condensed milk to produce the desired effect on 

 the sugar, the acid present would curdle the milk. Its use is of 

 no value to the manufacturer of condensed milk. 



Addition of Starch. The pasty and thick consistency" of 

 sweetened condensed milk frequently suggests to the public that 

 it contains starch. This is erroneous, for it is doubtful if con- 

 densed milk is ever adulterated with starch. There would be 

 nothing gained by so doing, and the presence of starch in con- 

 densed milk could be readily detected with iodine. Iodine gives 

 the starch cells a deep blue color. 



