222 BUTTER-MAKING. 



for inoculation are the same from day to day, the starter will 

 be ripe at nearly the same hour every day, and, consequently, 

 more uniform ripening results can be obtained. The notice- 

 able coagulation of the starter when skim-milk is used will 

 usually take place when there is about .6% of acidity. A 

 slight coagulation will take place when there is about .5% of 

 acidity, but it is hardly noticeable. The coagulation-point may 

 vary with different samples of milk. 



If a mother-starter is to be kept any length of time it 

 should be inoculated into a sample of good fresh pasteurized 

 milk about every other day. If a mother-starter, or starter 

 of any kind, is allowed to stand too long at a low temperature, 

 the desirable germs will become dormant, and some undesirable 

 germs will gradually gain a foothold. It is a good plan to 

 carry any mother-starter along for two or three days before it 

 is used to inoculate a large sample of milk. When the mother- 

 starter is first prepared it sometimes contains an undesirable 

 taste and smell from the medium in which the germs were 

 put up at the laboratory. This smell and taste is eliminated 

 by carrying it on two or three days previous to its use. 



While the starter, or mother-starter, is in the stage of 

 ripening it should occasionally be gently stirred. As soon as 

 coagulation of the milk begins, then starters of any kind should 

 never be stirred. If a sample of coagulated milk is stirred 

 before it is ready for use, it is more likely to "whey off." 



Length of Time a Starter Can be Carried. — In this country, 

 even if special precautions are taken, it seems almost im- 

 possible to carry on a starter for more than four weeks without 

 having undesirable ferments enter. The length of time a starter 

 can be carried undoubtedly depends upon conditions, and the 

 care with which it has been handled. When a starter is properly 

 prepared, cooled gradually before coagulation, and not overri- 

 pened, it will contain a smooth soft curd, and retain its mild acid 

 flavor for at least a month. The Danes, who use starters in 

 butter-making more regularly than any other people, are able to 

 carry a starter along for six months or more without renewing it. 



