620 BOARD OF AGRICULTUKE, 



acid bacteria, and no other, which thus far has not been excelled as tho 

 buttcrnuilvers' I'riend. 



Tlie following are the methods used in the Dairy Department of I'lu- 

 diu' University in preparing commercial starters. In selecting milk for 

 the preparation of starters we find it ditlicult to secure good quality. It 

 is our practice to heat the milk to about UU, at which temperature we can 

 detect undesirable odors which would not be found in the cold milk. Hav- 

 ing found satisfactory milk, it is pasteurized at a temperature of 200 de- 

 grees, held at least twenty minutes at this temperature, then cooled down 

 to S.J or 'JO and the pure culture added, keeping it at this temperature until 

 coagulate4. With the ordinary small sized bottle of pure culture we use a 

 pint of pasteurized milk if we want it ready in twenty-four hours. If 

 wanted sooner, use less milk, or if to be held forty-eight hours use a 

 (luart of milk. 



An important point is stopping the souring process at the proper stage. 

 I have found it best to reset, or use when acidity has reached six-tenths 

 of one per cent. It is a bad practice to let your starter get too much 

 acidity. Better be used Avith not enough than too much, because as soon 

 as the culture begins to coagulate the starter deteriorates. After you 

 have carried the pure culture to the point of coagulation it should be 

 reset, or used in the main starter, as we term it. This should be set at 

 a temi)erature of 65. The amount used should be about one-half to two 

 per cent, of mother starter, depending upon the strength of the culture, 

 as some work more rapidly than others. The per cent, to be used in the 

 cream depends entirely on conditions. Pasteurized cream should have 

 one-third more starter than raw cream, the amount depends on whether 

 you cau hold your cream at an even temperature, whether the cream is 

 high or low in per cent, of fat, and many other conditions which are too 

 numerous to mention, each one must study for himself. Generally speak- 

 ing, with unpasteurized cream, I would use ten to fifteen per cent, de- 

 pending altogether on the time before churning. 



The first thing to do in handling starter is that every vessel the cul- 

 ture comes in contact Avith must be thoroughly sterilized. Metal vessels 

 are preferable, as they can be kept more thoroughly steamed without 

 breaking. Second, the starter must be kept at an even temperature. 

 Third, we must educate our tastes so as to be capable of judging whether 

 or not the starter is of a quality that will improve our butter. A bad 

 starter will do as much harm as a good one will good. 



