2) 
2, SWEETENED CONDENSED Mi.K—HEaATING 
best, much of the steam used condenses in the milk, increasing 
the amount of water that has to be evaporated. It, therefore, 
prolongs the process of condensing and increases the cost of 
manufacture. This is especially true where the boilers are 
located at some distance from the hot wells and the steam pipes 
are not well insulated, causing the steam to be “wet,” and when 
the milk to be heated is cold. It 1s estimated that the amount 
of extraneous water thus added to the milk increases the bulk 
of the milk by about one-sixth of its original volume. The steam 
is often associated with impurities, such as cylinder oil from 
the engine, boiler compounds used in the boilers, scales from the 
inside cf the pipes, ete. These various impurities cannot possbily 
improve, but may seriously injure the quality of the milk. It is 
generally conceded by those who have given this matter careful 
Fig. 14. Steam rosette for heating milk 
Courtesy of Arthur Harris & Co. 
thought, that the turning of steam direct into the milk shortens 
the life of the product and causes it to develop a stale flavor, 
which may degenerate into an oily flavor. The same defect is 
noted also when cream is heated by turning steam into it. The 
prolonged exposure of the milk to the condensing process, as the 
result of the addition to the milk of considerable quantities of 
condensed steam, is an additional objection. 
From the above discussion it is obvious that the heating of 
the milk by bringing it in direct contact with free steam has 
some objections. Just to what extent this practice jeopardizes 
the quality has not been very conclusively demonstrated. But 
it is recommended that the heating with direct steam, if it must 
be practised, be confined to the last stages of the heating process, 
