THIRD ANNUAL YEAR BOOK — TART IX. 571 



wasn't accurate. Let me say that the creamery test is exactly 

 correct. Now would you advise these farmers to have these ma- 

 chines on the farms and test their own cream ? He tells his 

 neighbor about the discrepancy and they are both suspicious. 

 Supposing of course the creamery tests correctly. 



]\Ir. Farrington: Then I would advise the creamery <nan 

 to go out and teach him how to run his tests correctly. 



President: The next is "Pasteurization," by M. Mortensen. 



PASTEURIZATION. 



M. Mortensen, Sioux City, Iowa. 



It is the desire of every butter maker at the present day to make him- 

 self familiar with the subject of pasteurization. We pasteurize our milk 

 for starters so as to acquire control of the fermentation. We pasteurize 

 the skimmed mild in order that the farmer may have a better article for 

 feeding purposes, yet pasteurization of cream for butter making is only 

 practiced at a few creameries. 



By pasteurization we understand the application of heat to such a 

 degree that most of the bacteria are destroyed ; the temperature generally 

 made use of ranges between 140-185 degrees Fahrenheit. This should not 

 be confused with sterilization, by which we understand complete destruc- 

 tion of bacterial; this may be accomplished either by application of heat 

 or by use of chemicals. 



Every butter maker at present has become so familiar with pasteuriza- 

 tion that he can without difficulty pasteurize milk for starters, but pasteur- 

 ization of milk and cream for city supply, and especially cream for butter 

 making requires more experience and very careful work. The cooked 

 flavor which milk acquires after it has been heated to a temperature of 150 

 degrees Fahrenheit must be prevented when milk is to be sold for direct 

 consumption. The consumer generally objects to the cooked flavor; only a 

 few understand that the flavor serves as a guarantee that this milk is a 

 pure, healthy food. 



The Wisconsin Experiment Station recommends that the milk be 

 heated to 140 degrees Fahrenheit, for 30 minutes; that does not produce 

 the cooked flavor and does not affect the rising of the cream as do higher 

 temperatures. 



Pasteurization of milk and cream for direct consumption is continually 

 growing in favor. As to the digestibility of pasteurized milk compared 

 with raw milk, opinions are divided. Experiments along that line of 

 work have been conducted at the Maryland Experiment Station, where 

 they arrived at the conclusion that raw milk is more easily digested when 

 fed to calves than either pasteurized or cooked milk; they also corre- 

 sponded with physicians in charge of children's hospitals, and the majority 

 of them favored the use of raw milk for infants, when the milk was known 



