74 



DAIRY TECHNOLOGY 



or 500 quarts of milk i 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 $i 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. 



