COMMERCIAL STAIiTERS IN BUTTER MAKING. 49 



58. Preparing milk for the first propagation. (Per- 

 not.*) — The preparation of milk for the propagation 

 of a pure culture is very simple. Select two quarts 

 of good sweet whole milk or skim milk for this pur- 

 pose. (Either may be used satisfactorily but sweet 

 whole milk gives the Startoline more of a smooth, 

 pleasing taste than skim milk does.) Set two vessels 

 each containing one quart of milk into water and 

 heat it to 170° F.— 190° F. and hold at this tempera- 

 ture for about forty minutes. Cool quickly to 80° 

 F. and it is then ready for the addition of the pure 

 culture. For very large creameries use a large sized 

 bottle of pure culture and use one gallon of milk 

 divided into two jars of two quarts each. An excel- 

 lent method is to place the jars of selected milk in a 

 steam tight, wooden, tin-lined box the temperature 

 of which can be perfectly i-egulated and pasteuriza- 

 tion assured. Another method is to tie parchment 

 paper over the necks of the jars and then place the 

 jars on a shelf through which steam is conducted. 

 Turn a large tin pail over them, turn on the steam 

 and heat as mentioned above. Then cool by placing 

 the jars first in warm water (to avoid breaking 

 them) and then gradually running cold water 

 around them. 



59. Adding the lactic ferment culture. When 

 the milk is prepared as previously directed get the 

 little bottle of pure culture, clean the sealing was 

 carefully from the neck of the bottle and empty 

 one-half of the contents into each bottle of the pas- 

 teurized milk. Now close the jars or vessels con- 



* Pernot, E. F. Bui. No. 83. Oregon, 1904. 



