FARM DAIRYING 403 



Propagation of starter for butter-making (Guthrie and Fisk) . • 



A starter is a material containing desirable bacteria for the 

 ripening, or souring, of dairy products. These bacteria may 

 be purchased of companies whose advertisements appear in the 

 dairy journals. The growing of the bacteria in whole milk or 

 in skimmed milk is known as starter making. 



The method presented may sometimes be varied and still 

 good results be secured, but a beginner should not experiment 

 until he fully understands the principles involved in the propa- 

 gation of starter. 



In the cultivation of starter the usual practice is to carry 

 the starter from day to day in a small quantity, which is more 

 carefully handled than the major part. This small amount of 

 starter is termed "mother starter." The choice of containers 

 for mother starter depends largely on conditions and on the 

 preference of the operator. Glass is somewhat preferable, for 

 through it dirt is easily detected and the condition of the curd 

 is readily noted. Two or three bottles should be used, for in 

 pasteurization they may break. Metal holders, as copper 

 properly tinned, or heavy tin, may be used. It is always well 

 to use a sufficient number of containers so that careful selection 

 is possible. 



Usually it is necessary to propagate the mother starter two 

 or three times before the flavor of the commercial culture, which 

 is often very disagreeable, will disappear. 



The steps in propagation of mother starter are as follows : 



1. Take three one-quart bottles or fruit jars. 1 



2. Use fresh, clean milk, which must have a good flavor. 

 It may be either whole milk or skimmed milk. Usually it is 

 advisable to use whole milk, for it is easier to choose desirable 

 samples before milk has passed through the separator than 

 afterward. 



3. Fill the containers one-half to two-thirds full of milk. If 



1 Larger receptacles may be used if desired. 



