CREAM-RIPENING. 201 



acid. Some undesirable germs also, in a vegetative stage, are 

 not destroyed at this temperature. For this reason cream 

 should be heated to about 180° F. At this temperature, the 

 germs causing tuberculosis are destroyed. It is in order to com- 

 bat this disease that the Danish Government compels all cream 

 to be pasteurized before it is made into butter, and also all of 

 the skim-milk before it is returned to the farmer. The germs 

 causing tuberculosis are destroyed at a lower temperature than 

 this (180° F.), provided they are exposed to the temperature for 

 some time. In creameries the intermittent method of pasteur- 

 ization is used. In this method the time of exposure to the heat 

 is short, and consequently a higher temperature is necessary. 



By heating milk to such a temperature practically all of the 

 germs, desirable and undesirable, are destroyed with the ex- 

 ception of those that are present in the spore form. If this 

 cream is inoculated with the desirable germs, then theoretically 

 and practically, good uniform results should be obtained. 



It was mentioned above that the spore-bearing bacteria were 

 not destroyed by the degree of heating to which cream is ex- 

 posed. If the cream is allowed to stand any length of time at 

 a favorable temperature without a starter in it, these spores 

 will develop and cause undesirable results. If pasteurized 

 cream is allowed to ripen naturally, a very bitter flavor usually 

 develops. In order to overcome this undesirable fermentation, 

 it is essential that the starter should be added as soon as possible 

 after the cream has been cooled down to the desirable ripening 

 temperature. It should be remembered that this starter should 

 never be added to the cream while it is still hot, as the lactic- 

 acid-producing germs in the starter would then be destroyed. 



Ripening Cream When Churning is Done Once Every Other 

 Day. — At certain seasons of the year the milk delivered to the 

 creamery is not sufficient in quantity to produce enough cream 

 so that it is worth while to churn every day. Many makers 

 profitably utilize their time by churning only every other day. 

 The question then comes, how may the cream be preserved in 

 the best possible condition? Some prefer to cool the cream to 



