FARMERS' INSTITUTES. 155 



my experience goes there is no advantage in letting milk stand in cold 

 deep settings longer than 24 hours — but 36 is better for shallow pans, 

 so long as the milk does not sour. 



If the milk is separated by means of a centrifugal separator there is no 

 better time to do it than when it is fresh from the cow. If the milk has 

 become cool, however, it should be warmed up to about 86°. 



The advantages of the separator are that there is less loss of butter fat 

 in the skim milk, the cream is of a uniform consistency, less tank room 

 and ice are required and the skim milk is in the best possible condition 

 to feed the calves. 



I have no doubt that in every hundred pounds of skim milk from shal- 

 low pans there is enough butter fat to make a pound of butter. By the 

 use of the separator practically all of this loss is saved. 



HANDLING THE CREAM. 



In whatever way the cream is gathered great care must be exercised 

 in handling it. The small lots of cream which have to be saved till we 

 get a churning should be kept as cool as possible and should be stirred 

 every time a new lot is added. When enough for a churning has been 

 obtained, remove to a warm place or heat up to from 60° to 65° and allow 

 to stand for twenty-four to forty-eight hours to ripen. If you are in a 

 hurry, a little good sour milk or buttermilk may be added as a starter. 

 The purpose of allowing the cream to stand at this warmer temperature 

 and of adding the starter is to induce souring, or ripening as it is called. 



There are several reasons for ripening cream; we get a better flavored 

 butter; we get a more exhaustive churning; less butter fat is lost in the 

 buttermilk, and it does not take so long to churn. 



Then there are reasons why the temperature of 60° to 65° is best for 

 ripening. Milk sours as a result of the growth of minute germs in it; 

 the acid which makes the cream sour and gives the butter its flavor is 

 a by-product of their growth. There is no less than twenty different 

 forms of bacteria which produce acid in milk, and numerous other forms 

 are probably always present. By experiment it has been determined that 

 those forms most favorable to good results in butter making thrive best 

 at the temperatures named. At low temperatures there is danger of the 

 bitter fermentation, while at higher, slimy and other objectionable 

 changes are liable to occur. 



As soon as the cream is ripe, having a pleasant acid taste, and thick 

 in consistency, it should be cooled down to a low temperature for churn- 

 ing. Churn at as low a temperature as possible and have the butter come 

 in a reasonable length of time. 



The point is to have the butter come at a low temperature. In sum- 

 mer I would churn cream at as low a temperature as I could get it, and 

 in the winter I would not churn it above 56° or 58°. 



The richer the cream the less butter fat there will be lost in the butter- 

 milk and the sooner the butter will come. Cream from cold, deep settings 

 should therefore be churned at higher temperatures than thick separa- 

 tor cream. 



