74 



DAIRY TECHNOLOGY 



or 500 quarts of milk 1° F. It is necessary to heat the 

 milk about 100° F. 100 pounds of steam are then re- 

 quired to heat 1000 pounds of milk 100° F. As i pound 

 of coal produces about six pounds of steam, about seven- 

 teen pounds of coal are necessary to pasteurize the 1000 

 pounds of milk. The cost of this coal at $6.00 per ton, 

 is about 5.1 cents. It costs an equal amount, 5.1 cents, 

 to bring the temperature of the boiler up to the point of 



Fig. 6. — View of C. P. pasteurizing machine. 



steam pressure. The cost of cooling this amount of milk 

 may be estimated at 50 cents. If the pasteurizing ma- 

 chinery costs $2000 the depreciation of same may be 

 estimated at $1 per day; thus the machinery should last 

 10 years. The interest at 7 per cent amounts to about 

 forty cents per day. In addition it costs $1.50 for one- 

 half day's labor. The total cost of pasteurizing 500 quarts 

 of milk 100° F. is then about $3.50 per day, or 0.7 cent 

 per quart. 



