PASTEURIZATION OF MILK AND CREAM 113 
On an average about 2 per cent of the total bacteria 
found in milk are present in the spore stage in which 
they cannot be destroyed by the pasteurizing process; 
hence the necessity of holding milk at such low tempera- 
ture as will prevent the development of these spores into 
actively growing organisms. ‘These spores, if enabled to 
develop sufficiently, will impart undesirable flavors to 
milk; and, furthermore, it is these putrefactive kinds 
which are responsible, too, for a great many diarrheal and 
gastro-intestinal troubles of children. Pasteurized milk 
may appear perfectly sweet to the consumer but may be 
actually dangerous to children if it is kept at tempera- 
tures which will permit a rapid development of putre- 
factive and other kinds of spores. To keep pasteurized 
milk in a good condition, its temperature should not be 
allowed to exceed 50° F., and much lower temperatures 
are desirable. 
Viscogen. Thorough pasteurization reduces the vis- 
cosity or whipping property of cream. To assist in re- 
storing the original viscocity, a solution of sucrate of 
lime is added which is known as viscogen. This solu- 
tion is made by adding an excess of slaked lime to three 
parts of sugar dissolved in five parts of water. The 
mixture is allowed to stand twenty-four hours, after 
which the clear liquid at the top is poured from the 
sediment and preserved in a stoppered bottle at a low 
temperature, 
Add one part viscogen to about 150 parts of cream. 
Never add so much as to render the cream alkaline. 
While viscogen is entirely harmless, it is nevertheless 
an adulterant and cream treated with it must be labelled 
so as to indicate that it has been treated with viscogen. 
By holding pasteurized cream at low temperatures a 
