330 DEFECTS FOUND IN BUTTER 



were 339 and 356 days. The skim-milk from the stripper milk 

 was permitted to sour and was then used as a starter for souring 

 or ripening the cream separated from the stripper milk. The 

 fresh cow's milk used for a starter was produced by a cow that 

 had been thirty days in lactation. The skim-milk was per- 

 mitted to sour in the same way as that from the milk of stripper 

 cows. 



Various tests were made of the butter made from the dif- 

 ferent milks. This butter was scored by W. S. Moore, who was 

 then official scorer for the Elgin Board of Trade, and knew 

 nothing of the nature of the experiment. The tubs of butter 

 were all scored by number, and received practically the same 

 score. The two highest-scoring lots of butter scored 95; one 

 of these lots was made from the stripper milk and the other 

 from fresh cows' milk. 



From 'this and similar experiments reported in Bulletin No. 32, 

 Iowa Experiment Station, it would seem that the period of lac- 

 tation has little or.no effect upon the flavor of butter, that is, 

 when the milk is separated by centrifugal force, or by the little 

 hand separator. Under the gravity system there may be some 

 difference, as many dairymen claim there is. A possible explana- 

 tion is that the fat-globules, as is well known, are smaller in the 

 milk of cows well advanced in lactation, and when cream from 

 such milk is raised by the gravity process more time is required 

 for the cream to rise than when the milk is from fresh cows 

 whose milk contains fat-globules of much greater size. 



A bitter flavor is frequently found in milk or cream that is 

 kept for a long time at a low temperature. There seems to be 

 present in almost all milk an organism that is able to produce a 

 bitter flavor in. milk or cream at low temperatures, which are 

 unfavorable to the development of the lactic acid organisms. 

 Hence, the defects attributed to the period of lactation of the cow 

 may be due to the method of separating the cream. 



It is the aim of almost all farmers to have their cows come in 

 fresh in the spring. Therefore, during the early winter months 

 most of the cows are well advanced in their period of lactation. 

 At this time they are milked in the stables and fed on dry feed, 



