110 Evaporated MiIvK — Homogenizing 



145.5 

 Specific gravity = ' " -'— — ; B = Beaume reading at 60 



degrees F. 



Example: Beaume reading at 60 degrees F. is 8 degrees B. 

 What is the specific gravity? 



145.5 



Specific gravity = -— = 1.0582 



145.. 5 — o 



Chapter IX. 



HOMOGENIZING 



Purpose. — The introduction of the homogenizer in milk con- 

 densing factories is a comparatively recent innovation. TLe ob- 

 ject of its use is to avoid the separation of the butter fat in the 

 evaporated milk after manufacture. 



The butter fat is present in milk in the form of minute 

 globules. These fat globules are lighter than the rest of the 

 ingredients of the milk. They, therefore, show a strong tendency 

 to rise to the surface and to form a layer of thick cream in the 

 cans. When these cans are subsequently subjected to agitation, 

 as is the case in transportation, this cream churns, forming lumps 

 of butter. This tendency of evaporated milk to separate in stor- 

 age and churn in transportation is especially noticeable with 

 milk rich in fat und in which the large fat giobules predoiminate. 

 In Jersey and Guernsey localities, it is more difficult, therefore, 

 to manufacture evaporated milk that does not separate, than in 

 Holstein and Ayrshire localities. While separated and churned 

 evaporated milk is perfectly sound and in every way as valuable 

 as a food, as it would be without this separation, it does not sell 

 in this condition. It is rejected on the market. 



This tendency toward fat separation can be minimized and 

 frequently entirely prevented by increasing the viscosity of the 

 evaporated milk. This can be accomplished by superheating the 

 milk in the pan or after it leaves the pan, and by prolonging 

 the sterilizing process, raising the heat very slowly or stopping 

 the reel of the sterilizer at certain stages of the process. How- 



