194 BUTTER-MAKING. 



dency of the desirable. When such overripened cream is 

 churned, these undesirable germs are transmitted to the butter, 

 and cause deterioration. If the butter is churned from properly 

 ripened cream, and at the proper ripening stage, and the butter 

 washed in purified water, very few undesirable germs are trans- 

 mitted to the butter, and, as a consequence, it keeps better. 



Ripening Temperature of Cream. In practice, the ripening 

 temperature of cream varies within wide limits. Some makers 

 prefer to ripen cream at a temperature of about 80 F., others 

 ripen at about 70 F., and still others prefer to ripen at a tem- 

 perature between 60 and 70 F. Undoubtedly, the conditions 

 in the creamery will to some extent govern the ripening tem- 

 perature. Up to a certain limit the higher the temperature, 

 the quicker the ripening process. In some instances, it is 

 desirable to ripen and cool cream in a few hours, and then 

 churn the same day. Under such conditions a comparatively 

 high ripening temperature is undoubtedly preferable, as the 

 cream will sour more quickly at such a temperature. Un- 

 doubtedly good butter can be made at any of the temperatures 

 mentioned above, but when we are to decide which temperature 

 is the best, we are, through experimental evidence, forced to 

 come to the conclusion that a ripening temperature between 

 60 and 70 F. gives the best results. 



When cream is ripened at a high temperature it needs to be 

 cooled very little previous to ripening. Milk is usually sepa- 

 rated at a little above 80 F., and if the starter is added imme- 

 diately after separation, it will ripen in a very short time. 

 If ripened at a lower temperature, a longer time will be re- 

 quired to develop the same amount of acid, and hence with a 

 prolonged ripening period more attention is necessary. The 

 Danish butter-makers ripen their cream at a comparatively 

 low temperature, usually between 60 and 65 F., and obtain 

 the best results. 



The germs producing lactic acid grow within a wide range 

 of temperature; viz.: from about 50 to 100 F. The extreme 

 temperatures are not favorable to the greatest possible growth. 



